Eao annual scientific meeting report 2015

Congress Scientific Report EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

Issue 1, April 2016

Contents Introduction �����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������1 Acknowledgements �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������1 Methodology �����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������1 Copyright �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������1

50 years of clinical osseointegration – the early contributions and current effectiveness in implant dentistry ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������2 Per-Ingvar Brånemark concept. ���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 2 André Schroeder concept ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������3 Willy Schulte concept ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������4 Effectiveness in implant dentistry ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������5 Chairpersons’ conclusion ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������5

Tissue reconstruction/regeneration ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 6 What the dentist needs to know about tissue reconstruction/regeneration ����������������������������������������������������������������� 6 Extracts from the video ‘Cell-to-Cell Communication’ ��������������������������������������������������������������������������������������������������������������������������������������������7 Regeneration/reconstruction of peri-implant soft tissues ����������������������������������������������������������������������������������������������������������������������������� 8 Tissue regeneration via the use of L-PRF ���������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 10

Challenges for implant treatment of the ageing population ������������������������������������������������������������������������������������������� 11 Bisphosphonates; a threat or an option? ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 11 No teeth, no money: what to do in the elderly patient? �������������������������������������������������������������������������������������������������������������������������������������13 Minimal number of implants in the upper jaw? ���������������������������������������������������������������������������������������������������������������������������������������������������������������� 15 Minimal number of implants in the lower jaw? ������������������������������������������������������������������������������������������������������������������������������������������������������������������16

Implants in the future: CAD-CAM, precision of fit ������������������������������������������������������������������������������������������������������������������������������������ 17 The future implant crown: chairside vs. labside ���������������������������������������������������������������������������������������������������������������������������������������������������������������17 Is ceramic the material of choice for future implants? ���������������������������������������������������������������������������������������������������������������������������������������� 19 CAD/CAM in removable prosthodontics ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 20

To learn from complications ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 21 Maxillary sinus grafting complications and how to avoid them. �����������������������������������������������������������������������������������������������������������21 The surgeon as the complicating factor. ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������23 On the evolution of complications in implant prosthodontics. ��������������������������������������������������������������������������������������������������������������24 What have we learned from mucogingival complications? ����������������������������������������������������������������������������������������������������������������������25 What have we learned from immediate implant placement and immediate restoration? ������������������25

Treatment and outcome challenges ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 26 The current use of patient centred/reported outcomes in implant dentistry. ��������������������������������������������������������� 26 Quality of life in patients undergoing bone grafting procedures ������������������������������������������������������������������������������������������������������27 Management of bone defects in the aesthetic zone. ��������������������������������������������������������������������������������������������������������������������������������������������27

Implants in the future: virtual planning, 3D printing and more ��������������������������������������������������������������������������������� 30 The virtual patient: how far away are we? ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 30 The origin, present and future of 3D printing �������������������������������������������������������������������������������������������������������������������������������������������������������������������������31 3D printing in maxillofacial surgery ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������31 3D printing in prosthodontics �������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 32

Consensus Conference 2015 ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 34 The patient undergoing implant therapy ������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������34 Digital technologies to support planning, treatment, and fabrication processes and outcome assessments in implant dentistry. ��������������������������������������������������������������������������������������������������������������������������������������������������������� 36 Soft and hard tissue aspects. ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������37 Therapeutic concepts and methods for improving dental implant outcomes. ������������������������������������������������������� 39

Successful supportive treatment – evidence for clinical efficacy ���������������������������������������������������������������������� 41 Peri-implantitis: diagnosis and prevention through case selection and proper treatment execution ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������41 Supportive therapy following treatment of peri-implant disease ����������������������������������������������������������������������������������������������������43 How successful is supportive therapy in prevention of peri-implant disease ������������������������������������������������������������43

Imaging (radiology) in treatment planning and follow-up ������������������������������������������������������������������������������������������������� 45 Presurgical imaging in implant treatment: from guidelines to clinical use ��������������������������������������������������������������������� 45 Do we still need to use Hounsfield scores in presurgical planning? ����������������������������������������������������������������������������������������� 46 Radiographic bone quality aspects in planning implant surgery ������������������������������������������������������������������������������������������������������47 Creating the virtual patient: how to integrate facial, optical and radiological imaging components ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 48

Peri-implantitis ����������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 49 The relevance of implant materials for peri-implantitis ������������������������������������������������������������������������������������������������������������������������������������ 49 The patient and the problem awaits Monday morning. What do I do? ����������������������������������������������������������������������������������� 50 Challenges in the treatment of peri-implantitis ���������������������������������������������������������������������������������������������������������������������������������������������������������������51 A comparison between periodontitis and peri-implantitis lesions ��������������������������������������������������������������������������������������������������52

Emerging surgical concepts ��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������� 53 Do we still need autogenous bone for ridge augmentation or can we use growth factors? ����������� 53 Soft tissue grafts out of the box. What can we expect in clinics? ��������������������������������������������������������������������������������������������������� 55 Emerging concepts in maxillofacial surgery: indications for graft materials ��������������������������������������������������������������� 56 The future of wound healing: can it still be improved? ����������������������������������������������������������������������������������������������������������������������������������������57

EAO Office 38 rue Croix des Petits Champs 75001 Paris Tel: +33 1 42 36 62 23 Email: info@eao.org Web: www.eao.org

European Association for Osseointegration europeanassociationforosseointegration eao_association

Introduction This report provides a summary of the 12 principal sessions that took place at the EAO’s 24th annual Scientific Meeting. The report was written by a group of delegates at the meeting, who have previously prepared a similar summary for circulation among their friends following past EAO meetings.

As described in the methodology below, all speakers were given the opportunity to review and amend the editorial that had been written about their presentation, although a significant minority did not respond to the editors’ requests for feedback. The EAO wishes to emphasise that this is not a peer reviewed scientific report. It was written by the team of volunteer delegates, albeit with input from a large number of the speakers represented. The contents do not necessarily represent the view of the EAO and readers are responsible for independently evaluating any information contained in the report. Nonetheless, the EAO hopes that the report will provide a useful and informative summary of the proceedings of its 24th annual Scientific Meeting.

Acknowledgements The EAO would like to gratefully acknowledge the substantial work carried out by Lino Esteve and Alberto Salgado in writing this report. They were supported by Ambrosio Bernabeu, David Esteve, Guillem Esteve, Emilio Sánchez Talaverano, and Andres Valdes.

Methodology The methodology underpinning this report is as follows: 1. A team of dentist delegates volunteered to write the report and arranged to attend all the sessions covered in it during the EAO’s 2015 meeting in Stockholm 2. They provided a draft summary of each presentation to the EAO, which arranged for a copywriting team to edit it. This was not a scientific editing process, and instead concentrated on grammar and consistency 3. The editors returned the edited contributions to the dentist delegates highlighting any questions they had 4. On receipt of responses to their questions, the editors updated the contributions, then forwarded them to each of the speakers featured, along with a request for a selection of their slides (selected by the writers) 5. Each author was emailed up to three times to request their feedback. The majority replied, and around 50% also supplied slides. Some speakers provided textual corrections but declined to provide copies of their slides 6. A small number of speakers did not respond to any of the emails sent to them, and as a result the editorial on their sessions has not been reviewed by them

Copyright A number of speakers allowed a selection of their slides to be included in this report. Readers should be aware that copyright in any original content included in these slides remains the property of the speakers, and/or any other third-party copyright holders. These slides must not be circulated other than as part of this report, and should not be copied or reused without the express permission of the relevant speakers.

Congress Scientific Report: EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

1

50 years of clinical osseointegration – the early contributions and current effectiveness in implant dentistry As is often the case with significant scientific developments, the early research that underpinned the development of osseointegrated implants occurred in several locations. Per-Ingvar Brånemark made the initial discovery and subsequently defined the term osseointegration, and as he began to publish his research, other centres conducted their own experiments into different aspects of this rapidly developing field. The three most important European foci of the early development of modern implant dentistry were Gothenburg, Bern and Tübingen. The first three speakers of this session discussed the work that was taking place in each of these centres. The final speaker went on to talk about the global consequences of implant therapy and its current impact and effectiveness.

Per-Ingvar Brånemark concept.

Tomas Albrektsson In the late 1950s P-I Brånemark was working in the field of micro-circulation at the University of Lund, and it was the knowledge he gathered there that led to his later discovery. While studying micro-circulation in rabbit bone, he noticed that the device he had implanted was stable in the bone and he couldn’t remove it. He saw the potential of this discovery, and three years later placed his first implant in a patient.

The initial results weren’t very good, with a success rate of the order of 50% in the first five years. There was a strong academic struggle and Brånemark’s ideas were initially considered dangerous. However, three independent Swedish professors subsequently wrote a positive statement about implants and opinion began to move in his favour.

The term osseointegration first appeared in a book in 1977, although Brånemark certainly claimed there was direct anchorage to bone beforehand. Initially, the limits of histology meant that he was not able to objectively demonstrate osseointegration.

P-I Brånemark was a brilliant clinical scientist who chose to explore the possibilities offered by osseointegration, rather than working on cellular research. Most of what he postulated in the 1960s was later verified, but not even he would have estimated the number of oral implants that are placed annually today. The official figure is 20 million, but some people say it is more. Either way it is an astonishing figure, and although he was convinced of his success he could not possibly have estimated the extent of that success.

Congress Scientific Report: EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

2

André Schroeder concept Daniel Buser The late Professor André Schroeder was an endodontist at the University of Bern. In the late 1960s he began to experiment with various implant materials in animal studies.

In close collaboration with Straumann, his team developed various kinds of prototype titanium implants based on the later abandoned concept of hollow-cylinder implants. The results of his animal experiments were published in German in the Swiss Dental Journal in 1976, 1978, and 1981. These were the first studies to demonstrate direct bone anchorage to implants using his own histologic method with non-decalcified sections. He called the anchorage he observed ‘functional ankylosis’.

Schroeder’s work has enriched the development of the field in three main aspects:

his team pioneered the use of a titanium plasmasprayed (TPS) surface. This was probably one of the first modified titanium surfaces, and was introduced in an effort to achieve maximum bone anchorage they introduced the conical connection, which was quite different from Brånemark’s hexagon and has now become almost universal Professor Schroeder’s third contribution is probably the most important: the introduction of non-submerged healing of one-piece implants that has led to today’s concept of tissue-level implants In addition to the direct scientific contributions he made, Professor Schroeder co-founded the ITI in 1980, followed by the ITI Foundation in 1988. Today, the majority of the ITI’s activities are educational.

The ITI Foundation has supported more than 400 studies throughout the world and granted more than $45 million for these studies.

Rough implant surface and a non-submerged healing • All implant prototypes in the mid 1970’s had a TPS implant surface and were 1-piece implants ✓ A non-submerged healing was mandatory ✓ At that time, implants were only placed in healed sites with sufficient bone volume

early 1970’s

late 1970’s

late 1970’s

2013: 30 years follow-up

Figure 1.2.1

Non-submerged healing of Implants • In 1986, after 12 years of clinical testing, André Schroeder initiated a new implant system with 2-piece implants ✓ Hollow-cylinder, hollow-screw and solid screw implants are integrated into one implant system ✓ In the beginning, a non-submerged healing was used, with GBR cases, a submerged healing was also applied

Buser, Weber, Lang: Tissue integration of non-submerged implants. 1-year results of a prospective study with 100 ITI hollow-cylinder and hollow-screw implants. Clin Oral Implants Res 1: 33, 1990 Buser, Mericske-Stern, Bernard, Behneke, Behneke, Hirt, Belser, Lang: Long-term evaluation of non-submerged ITI implants. Part I: An 8-year life table analysis of a prospective multi center study with 2359 implants. Clin Oral Implants Res 8:161, 1997 Chappuis, Buser, Bragger, Bornstein, Salvi, Buser: Long-term outcomes of dental implants with a titanium plasma-sprayed (TPS) surface: A 20-year prospective case series study in partially edentulous patients. Clin Impl Dent Rel Res 15:780-90, 2013

1986

Figure 1.2.2

Smooth vs. micro-rough vs. rough Implant Surfaces • In 1988, an animal study was performed together with Sam Steinmann and Bob Schenk to examine implant 80 surfaces ✓ Goal: Find a better, non-coated titanium surface

3 weeks

6 weeks

60

40

20

0

E

SMP

SL

TPS

SLA

HA

Buser, Schenk, Steinemann, Fiorellini, Fox, Stich: Influence of surface characteristics on bone integration of titanium implants. J Biomed Mater Res 25: 889, 1991

Figure 1.2.3 Congress Scientific Report: EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

3

Willy Schulte concept Joerg Meyle The Frialit I immediate implant (Tuebingen implant) was developed in 1975 at the University of Tübingen and started being used in clinical practice in the 1980s. It was made of a polycrystalline ceramic of aluminium oxide and had an increased surface area due to its roughness in the endosseous part.

Conceived to fill the post-extraction alveolar socket after an impacted flapless insertion, its design took the form of a stepped cylinder. Problems arose because the material was more fragile, especially

in the smaller diameters. It was also based on the concept of filling the whole alveolar volume at the same time of tooth extraction. The next evolution was the Frialit-II, made of titanium, whose design evolved to a threaded but still stepped cylinder.

The main contribution this concept made to the field was pioneering the immediate insertion of implants post-extraction, which has now become a routine treatment.

The Schulte Concept and the Tuebingen Implant

The Schulte Concept and the Tuebingen Implant

Principles  Increase of surface area compared with root surface of extracted tooth

Schulte W, Heimke G: [The Tuebingen immediate implant] Concept Development Clinical Application Prof. Dr. Dr. h.c. Willi Schulte 1929 - 2009

Quintessenz 27, 1 (1976)

Consequences

100%

114%

145%

140%

Dtsch Zahnaerztl Z 33, 319 - 325 (1978)

Figure 1.3.1

Polycristalline Aluminumoxide Ceramics

Figure 1.3.2

The Schulte Concept and the Tuebingen Implant

Concept

The Schulte Concept and the Tuebingen Implant

Principles  Immediate insertion after tooth extraction  Flapless insertion  Primary stability

Development Clinical Application Consequences

D‘Hoedt B: Dental Implants of polycrystalline aluminum oxide ceramics - healing and longterm results Habilitation Thesis (1991)

Figure 1.3.3

Figure 1.3.4

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Effectiveness in implant dentistry Jan Derks Existing research does not provide insight into the overall effectiveness of implant dentistry, i.e. outcomes in a general population treated in everyday conditions. The majority of papers published in the implant literature are case series, which usually include small, selected patient groups (evaluation of efficacy)1 and are limited to reports on implant survival or implant success. To extend our understanding, additional parameters, such as patient satisfaction and the occurrence of complications, have moved into focus. In addition, it was suggested to identify the patient as the unit of analysis, rather than considering the single implant, thus facilitating the clinical relevance of research data. Assessments of effectiveness require large and randomly selected patient cohorts in which both rare and more common events may be studied. Assessments of risk, i.e. risk indicators, can be performed.

The speaker presented results from a project recently performed at the Department of Periodontology, The Sahlgrenska Academy at University of Gothenburg.

The included patient cohort represented a background population of 25,000 Swedish citizens who had all been provided with implant-supported therapy in 2003. The cohort was identified in the database of the Swedish Social Insurance Agency and, thus, included patients treated by various clinicians in different clinical settings. Patient files of 2,765 individuals were obtained and, in addition, 596 patients were clinically and radiographically examined 9 years after therapy.

Patient satisfaction In an initial questionnaire study on patient-reported outcomes, performed 6 years after completed therapy, it was concluded that patient satisfaction was generally high2. Outcomes were related to the following background factors: age and gender of the patient the extent of implant-supported restorative therapy 1 Berglundh & Giannobile J Dent Res 2013 2 Derks et al. Clin Oral Impl Res 2015

the clinician performing the treatment (specialist vs. general practitioner) Implant loss The occurrence of implant loss was evaluated. Early implant loss was assessed in patient files, while late loss was scored at the 9-year clinical examination3. It was found that: 7.6 % of all patients were affected by implant loss over the 9-year period risk indicators for early implant loss were: periodontitis; smoking; implant length and implant brand risk indicator for late implant loss was: implant brand Peri-implantitis A further study, under preparation at the time of the presentation but now published, presented the prevalence of peri-implantitis4. Peri-implantitis was assessed in 596 patients attending the clinical and radiographic examination 9 years after therapy. The data revealed that: 23% of all patients presented with peri-implant health (absence of bleeding on probing) at all implant sites 32% of all patients presented with peri-implant mucositis (bleeding on probing but no bone loss >0.5 mm) 45% of all patients presented with peri-implantitis (bleeding on probing and bone loss >0.5 mm) 14.5 % of all patients presented with moderate/ severe peri-implantitis (bleeding on probing and bone loss >2 mm) risk indicators for moderate/severe periimplantitis were: periodontitis; number of implants; clinician providing the restoration; implant brand; jaw of treatment; distance from prosthetic margin to crestal bone at baseline

3 Derks et al. J Dent Res 2015 4 Derks et al. J Dent Res 2016

Chairpersons’ conclusion Other European pioneers also took part in the initial development of osseointegrated implants, along with some Americans, but the three groups described in this session were those which paved the way for the fundamental concepts of today’s implants. From this initial diversity, there was a pattern of convergence to the proven concepts that have successfully passed the filter of scientific evidence. The three historical contributions described (among many others) have led to the current situation, in which implant-based treatment has become, or is becoming, the worldwide standard for edentulous patients.

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Tissue reconstruction/regeneration This session provided an overview of current indications for predictable hard tissue augmentation, along with the latest understanding of the relationship between peri-implant soft tissue and crestal bone loss, plus techniques for harnessing the regenerative benefits of L-PRF. It also featured a discussion of how complex biological concepts can be communicated using the latest animation techniques, with a description of a series of films entitled ‘Cell to cell communication’.

What the dentist needs to know about tissue reconstruction/regeneration Luca Cordaro In recent years, tissue augmentation has become an increasingly routine tool within the dentist’s armoury. Current best practice dictates that implants are placed in a prosthetically driven way, and this frequently results in the need for peri-implant augmentation procedures. This general trend towards augmentation has created some clinical challenges. It has developed alongside demands for increasingly simple treatment protocols, as well as a desire to reduce patient morbidity, along with the ever-growing pressure to deliver predictable, aesthetically excellent results without complications.

In order to achieve these goals, it is necessary to understand the predictability of each of the clinical situations in which tissue augmentation may be used. The key factor underlying this is the type of defect. These can be categorised as follows.

horizontal self-maintaining horizontal vertical combined

Situations in which bone augmentation can be considered predictable are as follows: GBR for fenestration/dehiscence defects at the time of implant placement staged GBR or block grafting for horizontal augmentation in partially edentulous patients sinus floor elevation. There is evidence that autogenous bone grafting of the sinus shows a higher implant success rate, when compared with bone substitutes, in cases of residual ridge height of less than 5mm1

1 Pjetursson et al. J Clin Periodontol 2008

However, vertical augmentation in the mandible and in the aesthetic zone seems to be less predictable.

The results of a recent systematic review2 were summarised by the speaker in a table indicating the different defects and the corresponding techniques available.

For small defects, when it is possible to carry out grafting simultaneously with implant placement, do we need to submerge?

The evidence indicates that for a single implant in the aesthetic zone, with simultaneous bone augmentation for a moderate peri-implant defect, both transmucosal and submerged healing provide similar outcomes. Hence there is no need to submerge an implant in this clinical situation3.

What are the indications for block grafts, and what is the associated morbidity?

The use of block grafts for staged augmentation is well documented. The morbidity of intraoral bone harvesting seems to be lower than previously reported. Opinion differs as to the preferred choice of intraoral site in order to minimise complications.

What is a short implant?

The definition of a short implant is currently the subject of some controversy. There are three definitions in use: a conventionally short implant is defined as being less than 10mm long the EAO Consensus Conference 2015 defined a short implant as one with an infrabony component of ≤ 8mm

2 Milinkovic & Cordaro. Int J Oral Maxillofac Surg. 2014 3 Cordaro et al. Clin Oral Impl Res. 2012

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a recent new definition is based on an implant length of ≤6 mm Regardless of the definition, the literature tends to demonstrate acceptable outcomes in posterior maxillary and mandibular ridges for short implants when compared with conventional implants. Hence, short implants may be considered instead of vertical augmentation in posterior zones.

Narrow diameter implants (NDIs) NDIs have well documented clinical indications, including reduced mesio-distal space or reduced ridge volume, provided that the rules of implant positioning are followed. Despite this, the risk of biomechanical complications, especially implant fracture, should be taken in account.

Extracts from the video ‘Cell-to-Cell Communication’ Bernd Stadlinger Using visual techniques to illustrate and explain biological processes has been a challenging issue for scientists for centuries. As science has evolved, different approaches have been employed to help communicate the new knowledge that scientists have gained through their research. Early examples of this desire to communicate visually are the drawings created by neuroanatomists at the beginning of the twentieth century.

New imaging technologies are now providing additional opportunities to illustrate biological processes, and can be used to create important educational tools. Computer animation has a crucial role to play in this process.

This lecture described and introduced the series of 3D computer animated films called ‘Cell-toCell Communication’. There are four films in the series, entitled: ‘Osseointegration’, ‘Inflammatory

Figure 2.2.1

Reactions’, ‘Periodontal Regeneration’ and ‘Oral Health and Systemic Health’.

The films illustrate the cellular and molecular processes that are the basis of therapies underpinning implant dentistry. The animations they feature are based on current scientific knowledge, and represent the processes in 3D. They were produced by combining scanning electron microscopic images of relevant structures with the most up to date research on cells and molecular mediators. To illustrate what occurs at macro-, microand submicroscopic levels, the camera perspective shifts between three image planes. This enables viewers to gain a better understanding of the timeline of cellular processes, and uniquely offers a view of them in three dimensions. In the presenter’s words, the ultimate goal is to facilitate biological understanding and to stimulate an interest in the underlying science.

Figure 2.2.2

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Regeneration/reconstruction of peri-implant soft tissues Tomas Linkevičius Crestal bone loss (CBL) is thought to result from a combination of multiple factors, including implant hardware; crestal position; patient factors; and clinical handling, although the precise mode of its progression continues to be controversial. Early CBL arises at the time of establishing the biological width, while resorption at a later date can be seen in an ailing or failing implant.

Early CBL could be a predisposing factor for subsequent biological problems, since it may result in peri-implant pockets. Moreover, CBL may also lead to soft tissue recession, impairing the aesthetic result. This lecture discussed the contribution that mucosal thickness makes to CBL (Figures 2.3.1 and 2.3.2).

In an experimental study, peri-implant bone loss after abutment connection was correlated with a thin mucosa (<2mm)4. These results have been confirmed clinically in cases where it can be clearly stated that initial gingival tissue thickness at the crest was the significant factor influencing marginal peri-implant bone stability5, in both supra- and equi-crestal placements. Another clinical study by the same group concluded that platform-switching abutments did not preserve crestal bone better than conventional ones after one year of observation if thin mucosal tissues were present at the crest when implants were placed6 (Figures 2.3.3 and 2.3.4). This

4 Berglundh et al. J Clin Periodontol 1996 5 Linkevicius et al. IJOMI 2009 6 Linkevicius et al. JOMS 2010

data is consistent with another clinical observation of a correlation between CBL and abutment height7.

Given these results, how should clinicians best manage cases that involve thin mucosa (Figure 2.3.5)? The proposals put forward depend on the bone height: if bone height is >8mm, the three options are: bone reduction to passively augment soft tissue proportion; subcrestal placement to try and achieve greater soft tissue contact; or a ‘tent’ technique that involves covering the abutment with the flap to provide soft tissue growth (only viable if a major flap relapse can be obtained) if bone height is <8mm, vertical augmentation of the soft tissue is recommended. This can be carried out simultaneously with implant placement Three alternatives for soft tissue augmentation were put forward: using an autograft; a xenograft; or a dermis-derived allograft. Autografts produce significant soft tissue augmentation but do not appear to prevent bone loss. Collagen-matrix xenografts result in less augment of volume, since some recession is likely to occur. In a prospective controlled clinical trial, the authors used an allograft (human dermis-derived; Alloderm) and reported significantly less bone loss, probably due to its membrane effect8 (Figures 2.3.6 and 2.3.7).

7 Galindo-Moreno et al. J Dent Res 2014 8 Linkevicius et al. CIDDR 2013

Figure 2.3.1

Figure 2.3.2

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Figure 2.3.3

Figure 2.3.4

Figure 2.3.5

Figure 2.3.5

Figure 2.3.6

Figure 2.3.7

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Tissue regeneration via the use of L-PRF Marc Quirynen Platelet degranulation happens in the very early moments of the healing cascade, giving place to coagulum formation and the release of cytokines to orchestrate the inflammatory process. The idea of concentrating platelets to improve the wound healing process is not a new one. Platelet rich plasma concentrates (PRPs) have been investigated since the 1990s and their use has become increasingly widespread across a range of medical disciplines.

Faced with conflicting data and frequently biased reporting (closely linked to undisclosed commercial interests) the use of PRPs was almost abandoned in oral and maxillofacial surgery. However, what appears to be their inconsistent performance may be explained by the wide variety of products that were produced during a rush for patents.

Second generation platelet aggregates called platelet rich fibrin (PRF) are now available, with claims made that they have overcome the major drawbacks of the first generation products. PRF is designed to have a low cost and to be simple to prepare, without the need to add activators, enabling it to provide high concentrations of platelets without altering their activity.

Leukocyte content and fibrin architecture seem to be the two key characteristics of all platelet concentrates. These are responsible for PRF’s clinical effects and are the basis for its classification9.

In the meantime L-PRF (leukocyte-platelet rich fibrin) can be defined as follows.

L-PRF should be considered as a living human ‘tissue graft’ the preparation process was first described by Choukroun et al10 it is easily made: blood is taken without anticoagulant and is immediately centrifuged to obtain a dense fibrin-platelet clot made of a strong fibrin mesh with the platelets and leukocytes distributed within it. This architecture may be the cause of its ability to release multiple factors over a longer time frame

9 Ehrenfest et al. Curr Pharm Biotechnol 2012 10 Choukroun et al. Implantodonie 2001

L-PRF’s role as a primary wound matrix, combined with its antibacterial activity and its ‘membrane effect’ seems to offer additional explanations for its clinical benefits.

The lecturer continued with a demonstration of a variety of indications for L-PRF, including: treating osteonecrosis of the jaw protecting surgical wounds and providing better and faster healing with less post-operative symptoms, for example in third molar extractions (RCT) replacing connective tissue grafting (several RCTs) regenerating infra-bony periodontal lesions (several RCTs) replacing graft materials when augmenting the ridge (new RCT) covering a lateral window or as a sole graft material in sinus lifts (case series) as a coating on implants for better early stability and fewer losses to perform ridge preservation instead of using current grafting biomaterials In all cases, the presenter provided references, with most of the documentation published in the last three years.

L-PRF, what about the future?

L-PRF can become a standard in regenerative treatments. However, first of all, the classification of PRPs and PRFs (including L-PRF) has to be decisively standardised, along with the key parameters for their preparation and use. Even though many studies are in progress, well designed clinical studies are welcome. The effect of biomaterials in current use has to be compared with L-PRF for each of the clinical indications. A standard 3D automated method would be very useful to objectively quantify the bone formation11. Hopefully, these steps will all be achieved in the near future.

11 Van Dessel et al. Poster 613 presented at EAO 24th meeting in Stockholm 2015

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Challenges for implant treatment of the ageing population the first speaker, Per Aspenberg, discussed bisphosphonates. The use of bisphosphonates is growing worldwide, and they are commonly prescribed as a means of preventing osteoporosis. It is increasingly common to encounter patients who are candidates for dental implant treatment who are also taking bisphosphonates. As such, it is necessary to understand the issues that are associated with them the second speaker, Martin Schimmel, reviewed current approaches to treating elderly patients who are seeking implant treatment and are increasingly poor and frail, along with the particular factors that need to be taken into account among this population the other two speakers, Anja Zembic and Gerry Raghoebar, explored the possibility of reducing the number of implants in the upper and lower jaw respectively. They also looked at issues around morbidity and cost, both of which have particular relevance to older patients

Bisphosphonates; a threat or an option?

Per Aspenberg Bisphosphonates have a strong affinity with bone and bind to hydroxyapatite, producing a strong inhibitory effect against bone resorption. Their mechanism involves the inactivation and apoptosis of osteoclasts, leading to decreased bone resorption and remodelling (Figure 3.1.1).

area. This then becomes isolated by granulation tissue, before being expelled as a sequestration.

In ONJ, this sequence of events fails, as does the osteoclastogenesis, and as a consequence necrotic bone remains and infection spreads, establishing itself as ONJ (Figure 3.1.2).

As dentists we need to be particularly aware of a severe side effect of bisphosphonates (and other antiresorptive drugs such as denosumab): osteonecrosis of the jaw (ONJ). Although this is a multifactorial condition whose pathogenesis is not yet fully understood, its action can be summarised in a few words. Bone resorption is a protective mechanism that fails when osteoclasts are inactivated by bisphosphonates. When bone is traumatised or infected, osteoclasts are activated and rapidly resorb the neighbourhood of the infected

On the other hand, when applied locally, bisphosphonates have a ‘good’ side, changing the local balance between formation and resorption of bone (Figures 3.1.3–3.1.6). In one experimental study1, a 28% (p=0.0009) higher pull-out force and 90% increased pull-out energy was observed for bisphosphonate-coated screws, supporting the idea that implant surface immobilised bisphosphonates can be used to improve fixation in bone. These 1 Tengvall et al. Biomaterials 2004

Figure 3.1.1

Figure 3.1.2

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Figure 3.1.3

Figure 3.1.4

Figure 3.1.5 Figure 3.1.6

Figure 3.1.7

Figure 3.1.8

Figure 3.1.9

Figure 3.1.10

Figure 3.1.11

Figure 3.1.12

Figure 3.1.13

Figure 3.1.14

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results have been repeatedly confirmed in various animal models2 (Figures 3.1.7–3.1.9). The same group carried out an experiment on 16 patients, each of whom received two implants. The test implants 2 Wermelin et al. Acta Orthop 2007; Bobyn et al. J Bone Joint Surg Am 2009; Abtahi et al. J Dent Res 2012; Agholme et al. J Mater Sci Mater Med 2012

(bisphosphonate-coated) showed significantly higher implant stability quotient values and less marginal bone resorption (Figures 3.1.10–3.1.13).

The speaker concluded by saying that systemic use of bisphosphonates may cause ONJ, but local application can improve implant fixation (Figure 3.1.14).

No teeth, no money: what to do in the elderly patient?

Martin Schimmel Although the incidence of edentulism is falling in Europe, it still persists in some groups of the population who are at risk of being unable to benefit from treatment because they cannot meet its cost. The impact of edentulism on the patient’s health is important, and it is usually accompanied by some comorbidities, making treatment difficult (Figures 3.2.1 and 3.2.2).

Apart from the technical difficulties of treating medically compromised patients, there is a need to minimise the treatment burden and simultaneously keep the cost low. We need to consider how that might be possible.

Complete removable prostheses can now be made using CAD-CAM technology. Chair-side work can be simplified using a standardised procedure, and costs reduced using semi-industrial fabrication.

Figure 3.2.1

Figure 3.2.2

Figure 3.2.3

Figure 3.2.4

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Despite these opportunities, the pros and cons still need to be precisely established because the technique is still in the early stages of development (Figures 3.2.3 and 3.2.4).

are also good, with a positive impact on quality of life (Figure 3.2.5).

Often, the first prosthetic option to be considered in elderly patients is a conventional denture in the upper jaw and a two implant overdenture in the lower jaw. Overdentures can also replace the volume lost in atrophic jaws in a less invasive way than fixed implant-supported prostheses, and are easier to clean. The McGill Consensus (2002) stated that the mandibular overdenture on two implants should be considered the recommended standard of care3. The cumulative survival rate of implants placed as part of this treatment is high. Patient satisfaction levels

The trend towards conservative surgery in elderly patient has led to the increased use of reduced length and reduced diameter implants. Shorter and narrower implants allow more placements without bone augmentation surgery, thus helping to simplify treatment and reduce patient morbidity, cost and time. In a recent systematic review4, narrow implants were demonstrated to have a high mean cumulative survival rate. This held true even for the narrowest (<3 mm) implants and mini implants (Figures 3.2.6â&#x20AC;&#x201C;3.2.8). Such treatments must always be part of ongoing dental care approach, especially in frail elders.

3 Feine et al. Int J Prosthodont 2002; Thomason et al. Br Dental J. 2009;207(4):185â&#x20AC;&#x201C;6

4 Klein et al. IJOMI 2014

Figure 3.2.5

Figure 3.2.6

Figure 3.2.7

Figure 3.2.8

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Minimal number of implants in the upper jaw?

Anja Zembic When providing dental implant treatment to elderly patients, the goal is typically to keep the costs low while minimising surgical risks. One way to do this is to reduce the number of implants required to successfully support the restoration. Unfortunately, the number of implants cannot always be presumed to be the same as the number of teeth that would be required to support the same restoration.

Until recently, it was recommended that maxillary overdentures were supported by four implants, as a high failure rate was observed with two implants.

However, these conclusions were based on the use of machined implants, and increased survival rates have recently been reported for rough implants.

These surface-modified implants represent a new treatment option which requires further study, so the question of the ‘optimal’ number of implants is still a matter of debate.

Survival rates and number of implants The literature yields insufficient and low quality evidence about the success and survival rates of both maxillary overdentures and fixed prostheses, with regard to the number of implants: in a recent overall comparison5, implant loss rates for maxillary overdentures on < 4 implants were significantly higher than for four implants. Maxillary bone quality may be a factor influencing these findings. In a recent one year randomised controlled trial comparing maxillary bar overdentures on 4 or 6 implants, no significant differences were observed6 for fixed implant-supported prostheses, using 4–6 implants is a well-documented treatment option with a 95% estimated 10-year survival7. The indication for more than six implants is unclear from the current evidence

5 Kern et al. COIR 2015 6 Slot et al. J Clin Periodontol 2013 7 Heydecke et al. COIR 2012

Patient satisfaction and number of implants Patient-centred outcome measures suggest that the number of implants placed does not affect patient satisfaction8. Levels of patient satisfaction are considered to be an essential aspect of evaluating treatment outcome.

What is preferable, fixed or removable?

Overdentures are associated with more complications, but are easier to clean, cheaper, and provide superior patient satisfaction in terms of aesthetics, taste and speech. The duration of the period of edentulism is a crucial factor in the choice.

The longer the patient has been edentulous, the greater their preference for overdentures. A shorter period of edentulism is associated with a preference for fixed prostheses. Generally speaking, removable prostheses are the treatment of choice for the elderly.

Is fewer than four implants in the maxilla an option?

One three-year study involving 40 patients used only three narrow diameter implants to retain a maxillary overdenture. Participants found this option to be successful, and it was effective whether the implants were splinted or not; both for total or partial palatal coverage; and whether the method of attachment was a bar or a ball9. Another study which involved using two single implants in the canine region of the maxilla to support a removable denture yielded an 86% four-year survival rate with balls10.

A similar study involving a telescopic connection yielded 82% survival after two years, although it was concluded that this type of connection might be too rigid, thus leading to overloading11. There have been attempts to secure fixed prostheses on both three implants12 and even on two, and a viable treatment concept was found.

8 De Bruyn et al COIR 2015 9 Al-Zubeidi et al. Clin Implant Dent Rel Res 2011 10 Zembic et al. in preparation 11 Weng & Richter Int J Periodontics Rest Dent 2007 12 Oliva et al. IJOMI 2012

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Minimal number of implants in the lower jaw?

Gerry Raghoebar Patients with conventional mandibular dentures are often dissatisfied by the lack of stability they offer, as well as problems with retention. This can lead to pain during mastication, with a potentially significant impact on their nutritional and psychosocial condition, resulting in a reduction in their quality of life. To treat this problem, the ‘gold standard’ is the mandibular overdenture supported by two implants, as has been corroborated by a 10-year randomised controlled trial13.

In cases of extreme resorption of the mandible, is bone augmentation needed or can short implants also do the job?

Three different treatment options were compared in an RCT: a transmandibular implant; a sandwich osteotomy and implants; and short implants. Patient satisfaction was the same, regardless of the option, and no differences were demonstrated with regard to masticatory function14. Over the 10-year follow-up period, survival rates were slightly superior in the short implant group, where no retreatment was needed. No differences were recorded in radiographic bone levels15. As a result, the evidence is categorically in favour of short implants.

13 Raghoebar et al. Int J Oral Maxillofac Surg 2003 14 Stellingsma et al. J Oral Rehab 2005 15 Stellingsma et al. COIR 2014

Is age a problem?

The influence of patient age on clinical outcomes for two-implant mandibular overdentures has recently been compared in a 10-year observational study16. The data obtained for the younger and older groups was similar. Based on this, age should not be considered as the sole factor on which to exclude a patient.

A treatment proposal for the mandible based on bone height and width:17 12mm–6mm/≧6mm: no significant differences in implant survival, prosthetic aftercare and patient satisfaction between two or four implants during a 10-year evaluation period, even with 6mm implants 12mm–6mm/< 6mm: the same as with simultaneous augmentation <6mm: augmentation with iliac crest, with the placement of two or four implants at a second stage Might one implant be sufficient?

A five-year RCT that compared mandibular overdentures retained with one or two implants recorded no significant differences between the two groups18. The same conclusion has recently been reached in a systematic review and meta-analysis19.

16 Hoeksema et al. Clin Implant Dent Rel Res 2015 17 Raghoebar et al. IJOMI 2011 18 Bryant et al. J Dent Res 2015 19 Srinivasan et al. COIR 2015

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Implants in the future: CAD-CAM, precision of fit The first lecture in this session described the role of monolithic zirconia in manufacturing frameworks and implant crowns, underpinned by CAD-CAM procedures as tools for planning, designing and manufacturing dental reconstructions. The second speaker described his clinical experiences of one-piece ceramic implants, which are now a real therapeutic option. The third lecture looked at CAM manufacturing technologies as applied to removable prosthodontics.

The future implant crown: chairside vs� labside Per Vult von Steyern More than 80% of conventional impressions have observable errors that may affect the fit. To address this, the use of intraoral scanners is highly recommended, particularly since manufacturers have now improved the integration of their hardware and software with dental laboratories.

Monolithic zirconia Monolithic zirconia is perhaps the most interesting new material that is available. It can be used to fabricate the frameworks of implant-supported restorations. Although there have been few clinical studies to evaluate its use for crowns, monolithic translucent zirconia can be used to create a one-piece crown without veneering, and unlike traditional veneered zirconia, which is associated with frequent chipping, it is highly resistant to fracture1 (Figure

4.1.1). In order to improve its aesthetic appearance, a promising idea could be to add a vestibular veneer protected by an occlusal flange incorporated into the zirconia itself (Figure 4.1.2).

To properly handle these zirconia frameworks, some limitations must be overcome, as the material is hard to reshape and therefore it is difficult to make occlusal adjustments or to correct any imprecision or lack of passivity. The dimensions of the framework (which are different from metal-based restorations) also lead to some aspects that can be uncomfortable for the patient. The speakers’ method is as follows: take a conventional impression to assure the accuracy of this, verify the model using an acrylic jig

1 Johansson C, Kmet G, Rivera J, Larsson C, Vult Von Steyern P. Fracture strength of monolithic allceramic crowns made of high translucent yttrium

Material alternatives

oxide-stabilized zirconium dioxide compared to porcelain-veneered crowns and lithium disilicate crowns.

Acta Odontol Scand 2014;72(2):145–53.

Semi-monolithic zirconium dioxide

900-1200 MPa

Monolithic translucent zirconium dioxide

Traditional ”Zircona” Figure: Fahad Bakitian

Figure 4.1.1

Figure 4.1.2

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scan the master cast, with the scan bodies placed on to the implant analogues ask the lab to create an acrylic pre-shape made from the CAD file (Figure 4.1.3) this will be used functionally by the patient for two weeks to permit a full evaluation by the dentist and to get feedback from the patient during this test period necessary adjustments can be made, such as adjusting the occlusion, or reshaping for improved comfort or hygiene when the patient is happy with the pre-shape, it is scanned by the lab and the zirconia framework is ordered from the milling centre the lab then makes the white and pink porcelain veneering on the zirconia framework and cements the titanium interfaces between the implants and the zirconia structure Peri-implant soft tissue modelling: direct and indirect methods Peri-implant soft tissue around single crowns can be sculpted by repeatedly remodelling the

temporary crown with composite material. To this end it is useful to have an acrylic veneer made on the CAD file that mirrors the contralateral tooth.

This means the technician has to imitate a proven design that has been sculpted in the mouth. An alternative, faster technique is for the lab to send the practice the restoration directly, but in this case a skilled technician is required, along with very good communication between the clinician and the lab (Figures 4.1.4 and 4.1.5).

A new technique to objectively assess changes of volume The results of augmentation techniques are difficult to assess objectively. Intraoral scanning could prove to be a valuable method for standardising the results, enabling comparison of the different techniques (Figure 4.1.6). A prospective comparative clinical study was due to be published by the end of 2015.

Disadvantages

Evaluation under function using an acrylic preshape made from the completed CAD-file…

Time and expense Disturbs the tissue healing • Repetead removal of the provisionals • Composite (irritation)

Advantages?

Believed to be predictable Visualizes the design for the DT The patient can see the result before making the permanent reconstruction

Figure 4.1.3

Figure 4.1.4

The direct method Advantages?

Disadvantages

Fast/inexpensive

Require good communication with the DT

No material induced inflammation/irritation Uninterrupted healing

Require a skilled DT Risks with the ischemia?

Evaluation: using intraoral scanner to measure soft tissue volume changes Starting before surgery, then… during surgery after surgery after healing at follow-ups Preliminary results?

Figure 4.1.5

Figure 4.1.6

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Is ceramic the material of choice for future implants?

Eric Van Dooren Managing ‘the eternal dilemma’: thin biotype and discoloured substrate Zirconia is highly biocompatible and not prone to corrosion or chemical reactions. It is the strongest restorative ceramic material available, and improves aesthetic appearance with its white colour. It currently represents the ideal option for patients requiring metal-free restorations.

In the anterior maxilla, due to the gingival translucency, the grey of the titanium substrate becomes visible at the margin of the restoration. It is necessary to have a soft tissue thickness of about 3mm to mask this grey effect2, and this gingival thickness is rather unusual in the aesthetic zone.

With this in mind, the speaker described a zirconia monoblock implant that had been designed by Drs Rompen, Van Dooren and Touati to overcome this negative aesthetic effect. The challenge is that its position has to be precisely controlled both horizontally and vertically.

Prosthetic manipulation offers an additional opportunity to improve the appearance of the soft tissue margin, even in cases with compromised implant positions. For example, abutments with concave transmucosal profiles seem to allow for better and more predictable soft tissue stability and less mucosal recession than divergent profiles3.

2 Jung et al. In Vitro Color Changes of Soft Tissues Caused

by Restorative Materials. Int J Periodontics Restorative Dent. 2007;27(3):251–7 3 Rompen et al. Soft tissue stability at the facial aspect of gingivally converging abutments in the esthetic zone: A pilot clinical study. J Prosthet Dent 2007; 97(6): S119–S125

This leads on to the question of whether this material, when used with a concave profile, has sufficient resistance. Biomechanical studies have demonstrated that the impact fracture of one-piece zirconia implants does not differ from two-piece titanium implants when they are embedded in a material with a similar elastic modulus to alveolar bone4. This investigation also showed that the fracture line in the zirconia implants was in the first thread and not around the transmucosal waist, as could have been expected. Even after occlusal and buccal reduction, one-piece zirconia implants barely lose their fracture resistance5.

Thickening the buccal aspect by means of soft tissue grafting is another way of optimising the colour of the peri-implant mucosa. The speaker’s usual protocol for patients with a thin biotype involves socket preservation, combined with a connective tissue graft as coverage. It is also worth noting that irrespective of the bone or soft tissue dimensions6, zirconium implants always offer an aesthetic benefit compared with titanium implants.

With zirconium implants, the emergence profile is difficult to configure. Due to the abutment diameter of the one-piece implant, it is dependent on the crown. This can create a problem with subgingival cementation.

4 Silva et al. Impact Fracture Resistance of Two TitaniumAbutment Systems Versus a Single-Piece Ceramic Implant. Clin Implant Dent Rel Res 2011;13(2):168–73 5 Silva et al. Reliability of one-piece ceramic implant. J Biomed Mater Res. 2009;88B: 419–26.

6 Thoma et al. Discoloration of the Peri-implant Mucosa Caused by Zirconia and Titanium Implants. Int J Periodontics Restorative Dent. 2016;36(1):39–45

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CAD/CAM in removable prosthodontics Daniel Wismeijer CAD/CAM-fabricated implant-supported restorations Digitally fabricated removable prostheses are a reality today. The prostheses can be CAM manufactured using either subtractive or additive technologies. The former involves a milling process and uses a pre-polymerised acrylic block. The latter is achieved using stereo-lithography or other 3D printing systems. It is slowly replacing the subtractive technique. CAM fabrication lowers costs and reduces chair time.

The current commercially available systems all begin with analogue impressions which are subsequently scanned in the laboratory. Occlusal aspects and tooth positions have to be adjusted with the restoration in position. So, instead of talking about a fully digital process, we should instead describe it as an analogue technique with some digital components.

The workflow is as follows (Figure 4.3.1): during the first appointment the dentist takes the impressions, creates inter-occlusal records and positions the teeth.

Once these records have been scanned, the data are imported into a program which allows the teeth to be virtually articulated and the prosthesis to be virtually designed (CAD) (Figure 4.3.2). The file is then exported to a milling device or 3D printer for the fabrication of the denture (CAM) which is ready to be placed during the second appointment.

In the near future it will be possible to capture the ‘whole patient’ digitally by merging data from different scans with the bone dimensions recorded and virtual representations of the real smile, surrounded by the patient’s facial soft tissues (Figure 4.3.3). There are still some problems in achieving this goal. These include the ability to take dynamic impressions of the patient; the ability to digitally record jaw border movements; and finally the ability to superimpose all data with sufficient precision.

Avadent production process

1

Scan impressions

2

Scan AMD

3

Digital design

4

Milling denture

CAD CAM in removable prosthodontics Figure 4.3.1

5

Finishing

CAD CAM in removable prosthodontics Figure 4.3.2

CAD CAM in removable prosthodontics Figure 4.3.3

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To learn from complications Maxillary sinus grafting complications and how to avoid them� Pascal Valentini Sinus grafting is a well-documented and frequently used augmentation technique. In a recent retrospective study, 54.2% of maxillary posterior implants were associated with a sinus augmentation1.

Although the procedure is undoubtedly predictable2, a variable percentage of complications have been reported, some of which are severe. The complications can be intra- or postoperative. Intraoperative complications may lead to postoperative 1 Seong et al. 2013 2 Valentini & Abensur. IJOMI 2003

complications, and both are closely linked to infection.

How to prevent these complications?

There are two main ways of preventing complications prior to surgery, and both relate to appropriate case selection: having precise knowledge of the anatomy of the sinuses in order to foresee and to manage intraoperative complications diagnosing the health status of the sinus and the anatomical particularities of the sinus to

Schwarz L, Schiebel V, Hof M, Ulm C, Watzek G, Pommer B. Risk Factors of Membrane Perforation and Postoperative Complications in Sinus Floor Elevation Surgery: Review of 407 Augmentation Procedures.

Prevention:

Dissection by erosion (ultra sonic sugery)

J Oral Maxillofac Surg. 2015 Jul;73(7):1275-82.

-

Septa Bone height < 3.5 mm Smokers 31.4% sinusitis in case of perfo (even treated with adsorbable membranes)

pascal/valentini

Figure 5.1.1

pascal/valentini

Figure 5.1.2

Idiopathic

Deviation of nasal septum

Del Gaudio & Wise 2006

Orlandi 2010

Uncinectomy

Septoplasty

Concha bullosa Ozkiriş M et al 2013

Turbinectomy

pascal/valentini

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rule out disturbed drainage in order to prevent postoperative complications The most common intra-operative complication is the perforation of the membrane lining the sinus (Figure 5.1.1). The prevalence of these perforations is reported with great disparity by different authors as ranging from 14 to 56%. The risk factors associated with sinus membrane perforation, listed in order of statistical significance, are3: septa and complex sinus morphology residual bone height less than 3.5mm smokers Membrane perforation is not easy to handle. The lecturer illustrated a closure procedure using one resorbable collagen membrane and titanium pins.

In cases of membrane perforation, there was a higher prevalence of sinusitis (31.4%), even after intra-operative closure, due to bacterial graft contamination or graft migration into the sinus cavity.

The second common complication is a vascular damage due to the presence of the alveolar antral artery with an intra bony passage. The best way to prevent intra- or postoperative bleeding is to dissect this vessel using ultrasonic surgery (Figure 5.1.2).

Postoperative complications The most frequent is an acute sinusitis which can occur 3 to 4 weeks post surgery. According to the literature, sinusitis seems to principally occur in patients who are predisposed to it. This predisposition can be diagnosed with a preoperative cone beam CT , CT scan or a presurgical endoscopic evaluation. Those examinations will allow us to detect a sinus pathology which can be a relative or an absolute contraindication. It is also possible to detect some anatomical particularities (Figure 5.1.3) which could disturb postoperatively

the sinus drainage as teeth which can induce a postoperative infection of the sinus graft (Figure 5.1.4). In most cases, an ear, nose and throat examination during the presurgical evaluation of the patient is recommended if they have any of the following history:

sinus inflammation polyps thickened sinus membrane nasal or sinus obstruction seasonal allergies

Generally speaking, if the patency of the ostium is insufficient, a functional endoscopic sinus surgery (FESS) procedure is indicated to restore the ventilation of the sinus (Figure 5.1.5).

The risk of postoperative infection is also increased by systemic factors. The patient’s medical status should be evaluated when planning sinus surgery to identify the following:

allergic patients (penicillin allergy?) osteoporosis treated with bisphosphonates immunocompromised patients diabetes (Hb1Ac>7%) haemostasis problems vitamin D deficiency

The following conclusions can be drawn: 1. A preoperative 3D radiographic study of the sinus is mandatory to assess the anatomical risks 2. The patient’s medical history must be checked to evaluate for systemic risks 3. Sinus grafting procedures should involve a team approach that includes ear, nose and throat colleagues in case selection and patient preparation, as well as management of possible postoperative complications

3 Schwarz et al. J Oral Maxillofac Surg 2015

antrostomy

Endodontics

acute sinusitis

Greenstein G, Cavallaro J Jr. Management of a perplexing sinus lift complication J Periodontol. 2010

Figure 5.1.4

polyposis

pascal/valentini

FESS

Figure 5.1.5

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The surgeon as the complicating factor� Franck Renouard Although some complications can be considered to be the result of errors, the role of ‘human factors’ is hardly ever taken into account when considering complications4. It is time to start examining the role that human behaviour and human attitudes play as complicating factors in implant dentistry.

Understanding the difference between faults and errors Mistakes can be divided into two main categories: faults and errors. A fault is a deliberate deviation from the rules of a particular protocol. An error is an inadvertent divergence from what the practitioner wanted to do. Fault or negligence has been found to be a factor in 27.6% of all serious adverse medical events5. A series of so-called ‘hazardous attitudes’ (for example being macho, impulsive or anti-authority; or attitudes of resignation, feeling invulnerable, or over-confidence) have been identified in the commercial aviation field. They have also been found to be present in 30% of a cohort of orthopaedic surgeons6.

Errors reduce safety margins When an error occurs in a simple case, it can normally be resolved without difficulty, but when margins are tight an error can lead to a disaster (for 4 Timmenga et al. J Oral Maxillofac Surg 1997 5 Brennan et al. Qual Saf Health Care 2004 6 Bruinsma et al. Clin Orthop Relat Res 2015; Kadzielski et al. Clin Orthop Relat Res 2015

example in anaesthesiology). Statistics from the USA which categorise deaths that are attributable to human errors are overwhelming (Figure 5.2.1).

The bad news is that, unlike complications, medical errors are rarely reported, and that is because we are scared to admit errors (Figure 5.2.2). Thus it is very hard to learn from our mistakes.

In one study which looked at 11,074 implant operations performed over 28 years, different levels of failure rates were observed between different surgeons7. These differences could have been due to individual surgeons’ attitudes and their capacity to cope with the stress.

Some tools to improve safe workplace practice The Sterile Cockpit Rule is an FAA regulation that requires pilots to refrain from non-essential activities during critical phases of flight. A similar model could be applied in surgical settings (Figure 5.2.3), for example, avoiding non-essential conversation during key stages of surgery.

The average risk of fatal events in general anaesthesia dropped progressively between 1970 to 2014, and has reached a safe level, partly thanks to a better understanding and grasp of human factors.

The same progression is possible in the field of implant dentistry (Figure 5.2.4).

7 Jemt et al. Clin Implan Dent Rel Res 2015

errors Estimated number of deaths per year in the US hospital system attributable to medical error: Death by medical error, ranking in list of most common causes of death in the US: Percentage of anesthesiologists who, when surveyed anonymously, admitted to committing an error with fatal results:

complications

98,000

incidents

5th 24%

errors (unreported occurrences)

Sources: IOM To Err is Human, , WrongDiagnosis.com Kaiser Health Poll Report 2003, Anesthesiology, 63:A497, 1985

Human attitude

Figure 5.2.1 Tools 4

Figure 5.2.2 safety Better understanding of how our bodies react to the placing of dental implants

Incorporation of Human Factors

Improvements in technology

The Sterile Cockpit Rule is an FAA regulation requiring pilots to refrain from non-essential activities during critical phases of flight,normally below 10,000 feet

Figure 5.2.3

1980

1990

2000

time

Figure 5.2.4

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On the evolution of complications in implant prosthodontics.

Bjarni Pjetursson Dental implant survival rates have been demonstrated to be very high. Real success means a long-term functional and aesthetic result that satisfies the patientâ&#x20AC;&#x2122;s needs â&#x20AC;&#x201C; that is to say, one that is free of complications. When looking at survival rates, many studies have also assessed biological complications. However, technical complications have received significantly less attention. This lecture looked at the incidence of different technical complications, and what we can learn from these.

Incidence The average complication rate reported over a 5-year period in one meta-analysis was 38.7%, and only 61.3% of patients were free of any complications8.

Rates of complications that affect the function of implant-supported reconstructions tend to increase over time. In a recent review, the 5-year rate of technical complications ranged from 16.3% to 53.2%9.

Problems with the screw and implant-abutment connection During occlusal loading, the most critical area is around the abutment screw head, where the highest torque and stress are concentrated. Hence, the most frequent technical complication reported is loosening or fracturing of the abutment screws. In one systematic review, the angle of loading and the type of connection were shown to be factors that influenced strength values in laboratory studies10.

Internal conical connections exhibited significantly greater strength and resistance to bending than external hexagonal connections. As a result, the occurrence of problems with abutment screws was lower in internal connections. However, this result is highly dependent on achieving a perfect fit. The lecturer showed a comparison between original and cloned abutments, with the latter demonstrating

a suboptimal fit, leading to a harmful stress concentration.

Recommendations to reduce the incidence of technical complications In the case of a single restoration, the lecturer recommended connecting directly to the implant using a single screwed interface. For a restoration on two implants, he recommended that at least one of these should take advantage of a full connection to the implant platform and, depending on the passive fit, the other could have an intermediate connection.

For abutments with a reduced contact area, ie multiunit abutments, he recommended using at least three implants to gain a degree of tripod resistance and reduce the associated forces. In posterior zones, it would be advisable to join the units together, although care should be taken to ensure they can still be cleaned.

How to avoid implant fractures Implant fractures are an infrequent complication with a cumulative incidence of 0.4% at 5 years and 1.8% after 10 years8. Despite their low incidence, they are the most severe category of complication as they lead to failure of both the implant and the prosthesis, with the associated surgical hazards of eventual reimplantation. Implant diameter has been shown to have a significant effect on fatigue performance during cyclic loading, but this effect is not consistent across different implant designs or implant materials.

These findings should be taken into account when designing the restoration, particularly in posterior regions and when parafunctional forces are to be expected.

Finally, comparisons between older and newer studies shows some improvements9, although there is still much work to be done before technical complications are reduced to an acceptable level.

8 Pjetursson et al. Clin Oral Impl Res 2004 9 Pjetursson et al. IJOMI 2014 10 Sailer et al. Clin Oral Impl Res 2009

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What have we learned from mucogingival complications?

Rino Burkhardt An initial analysis: complications and errors To answer the question posed in the title, we first have to establish a definition of what successful therapy is. The results of mucogingival therapy must be assessed in four areas: biology; function; aesthetics; and patient-centred outcomes. Failures in any of these four areas can result from complications or errors. A complication is an unfavourable evolution of an expected result of the therapy, i.e. unaesthetic recession of the soft tissue margin. An error is an adverse effect resulting from an unsuitable indication or the incorrect implementation of the treatment procedure.

The controversial keratinised mucosa It has been well-documented that the traditional belief in the need for an adequate width of masticatory mucosa in order to prevent loss of attachment of teeth is not scientifically founded.

But what about for implants? Four features of the peri-implant mucosa have to be assessed: width; thickness; mobility; and surface characteristics.

Is the absence of keratinised mucosa around implants an unfavourable feature with regard to soft tissue health? The number of studies that do or do not find significant differences in plaque and bleeding scores are roughly equal. There is a similar lack of clarity with regard to soft tissue dehiscences: some studies conclude that the width of keratinised mucosa is not a predictor of recession and that this only occurs in the early stage, while others cite mucosal thickness as a predictor of further recession, together with facial PPD11. To summarise, keratinised mucosa width may not be a critical factor, but mucosal thickness affects the stability of the peri-implant tissue seal. Regardless of the type of bordering tissues, significant positive correlations have been reported between plaque scores and bleeding on probing.

11 Wennström & Derks Clin Oral Impl Res 2012

What have we learned from immediate implant placement and immediate restoration?

Markus Hürzeler An evidence-based decision-making process should result from the combination of internal and external evidence, along with patients’ preferences and demands.

Primary stability, as well as the presence and dimensions of the buccal bone plate, are the main considerations used when deciding whether to place an immediate implant. In a recent systematic review, good aesthetic results were reported with the immediate approach, including positive assessment using the Pink Esthetic Score (PES).

However, marginal recession was present in 11% of the cases12. Another study, currently in preparation, reports a continued loss of volume after five years of observation, lowering the one-year success rate.

Factors which may influence the aesthetic outcome in cases involving immediate implant placement and immediate restoration are yet to be fully identified.

12 Khzam et al. J Periodontol 2015

Although implants that have been immediately loaded demonstrate high survival rates, the results from one meta-analysis have shown that they have a higher risk of failure, especially when they are unsplinted13.

Among other parameters, case selection should be based on the amount of buccal bone. With this in mind, it is sometimes possible to drill through the tooth before extraction, and to use narrow abutments plus a one-piece provisional.

In summary, comparing attitudes and results in 1997 to those 2015, patient demands are still the same, but we have more clinical experience and more internal and external evidence relating to immediate implant placement and immediate restoration. Despite this, we still need to evaluate the treatment concept with caution.

13 Sanz et al. Clin Oral Impl Res 2015

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Treatment and outcome challenges The current use of patient centred/reported outcomes in implant dentistry.

Jan Cosyn Implant treatment outcomes are usually assessed using objective parameters such as: implant and prosthesis survival rates; marginal bone loss; complications; and aesthetic indexes. However, the outcomes that patients care about may be quite different from these objective indicators. Assessing treatment on the basis of patient-centred outcomes is an increasingly common feature of research, in which the evaluation of patient satisfaction is considered crucial. Furthermore, if we want to know the real benefit of implant treatment as perceived by patients, we have to look through the eyes of the patient.

How can a subjective issue such as patient satisfaction be assessed?

As well as basic questionnaires focusing on general patient satisfaction, there is a need to ask more specific questions that examine the impact of different aspects of implant treatment on the patient’s quality of life. A systematic review has recently been published on the use of PatientReported Outcome Measures (PROMs) in implant dentistry1. The aim of this has been to try and update the list of PROMs and compare them against different types of implant treatments.

Is it possible to draw clear conclusions from PROMs? The authors of the systematic review noted that non-standardised questions and different scoring methods are commonly employed, compromising the validity and reliability of PROMS. Thus their first conclusion was that there is an urgent need for standardised reporting of PROMs. In addition to this heterogeneity, it was not always clear if patients in the studies had actively sought implant treatment; if they had been dissatisfied with their existing prostheses; or if they had paid for the treatment or

not. These are all factors that may introduce bias into the conclusions.

Are fully edentulous patients satisfied with implant treatment?

Mandibular overdentures consistently yield a higher satisfaction score than conventional dentures when assessed on parameters of comfort, chewing ability and stability. The outcomes for both types of prosthesis are comparable for speech, aesthetics and ease of cleaning. No differences in PROMs have been observed with regard to the number of implants or the type of attachments used. There is only limited PROM evidence on maxillary overdentures.

When comparing fixed versus removable implant prostheses, it seems that patients choose between the stability of the former or cleansability of the latter in a specific pattern, depending on factors including their age and the length of time they have been edentulous. As a result, patient attitudes should be taken in account during treatment planning.

What are patient perceptions of partial implant supported prostheses?

Although the number of controlled studies looking at PROMs as they relate to partial implant prostheses is scarce, it can be noted that: the timing of implant placement does not seem to affect patient satisfaction patients prefer straightforward surgery over complex surgical procedures or bone grafting a single implant is only chosen in one in five cases oral health related quality of life (OHRQoL) improves with a single or partial implant prosthesis patients express a clear desire to save natural teeth whenever possible

1 De Bruyn et al. Clin Oral Impl Res 2015

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Quality of life in patients undergoing bone grafting procedures Guido Heydecke Bone grafting is indicated to achieve stable implant placement if the available bone is insufficient.

Some adverse effects of bone grafting have to be considered, such as pain, swelling and impaired quality of life during the procedure and its healing process. Thus it seems highly appropriate to take the perspective of the patient into account during the decision-making process.

How is the burden of bone grafting perceived by the patient?

Several studies have investigated patient perceptions of bone grafting surgery, but comparison of the results is very difficult due to non-standardised approaches. The Health-Related Quality of Life (HRQoL) and Oral Health-Related Quality of Life (OHRQoL) tools are standardised, and both are wellaccepted methods for assessing patient perceptions.

Recently, HRQoL data (measured using the SF-36 questionnaire) and OHRQoL (obtained using the OHIP-49 questionnaire), along with pain data (assessed using the Visual Analogue Scale) was collected from 23 patients following intra- and extraoral bone grafting2. In addition, patients were asked a series of previously validated questions focusing on different aspects of their general and oral health, with the aim of quantifying and comparing 2 Reissmann et al. Clin Oral Impl Res 2013

levels of morbidity. A significant deterioration in physical HRQoL was reported from 3 days (processrelated) to 4 weeks (output- related) following bone grafting surgery. Levels were reported as being lower and longer-lasting for extra-oral donor sites.

By comparison, the impact of intra-oral grafting procedures on OHRQoL was quite modest. The figures showed similar changes regarding pain.

Based on these findings, intra-oral donor sites should considered preferable and selected wherever possible.

Is the patient’s perceived impact of implant placement higher than that of other surgical procedures?

Recent studies3 have shown that patients consider implant placement to be less burdensome than practitioners imagine. Results also show that they rate it as significantly less burdensome than practitioners even when bone and soft tissue manipulation is required, when compared with surgical tooth removal or apicectomy. The part of the procedure that patients consider most burdensome is local anaesthesia. Therefore, patients should be reassured that implant surgery is less burdensome and uncomfortable than other commonly performed oral surgery procedures.

3 Reissmann et al. J Dent 2015

Management of bone defects in the aesthetic zone� De-Hua Li Aesthetic appearance is a well-established criteria for implant success. Localised bone defects are anatomical challenges since they can compromise the placement of implants in a prosthetically ideal position. Thus, sufficient bone volume is considered to be a prerequisite for good aesthetic results.

The prevalence of cases in which there is insufficient bone can be estimated to be over 50%, although in situations involving anterior restorations it could be over 90%. In these clinical situations, guided bone regeneration (GBR) is often indicated, although there is a general perception that bone defect resolution is not 100% predictable in daily practice. Despite this, a

Guided bone regeneration Essentials of this technique • Stable barrier protection

recent systematic review found evidence of average survival rates of 95.4% for implants placed in either augmented bone or pristine bone. Nevertheless, the mean defect resolution was 81.7%, and complete defect fill was only reported in 68.5% of the cases4.

Clinical management of defects to solve this perceived unpredictability should be based on the following GBR principles (Figure 6.3.1 and 6.3.2): stable barrier protection adequate space for bone formation 4 Jensen et al. Int J Oral Maxillofac Implants 2009

Determinants to the stability of the grafting area • The topography of alveolar bone defects

• Adequate space for bone formation

• The location of bone defects

• Stability of the grafting area

• The modality of grafting procedure

• Osteogenic capacity of the local site

Figure 6.3.1

Figure 6.3.2

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stability of the grafted area osteogenic capacity of the local site The determinants of grafting stability are dependent on three factors (Figures 6.3.3–6.3.5): the topography of the alveolar bone, including the number of walls the location of the defect, and whether it is circular, vertical or features a perforation/ dehiscence the modality of the grafting procedure It is important to use an evidence-based defect classification when planning the treatment. Each type of defect has an associated surgical approach, level of difficulty and prognosis. A table combining topography and location can be used to classify the surgical complexity (Figure 6.3.6).

In self-containing defects, the procedure is straightforward and GBR can be performed at the

same time as implant placement. One particular type of case requires special mention: immediate postextraction implant placement. These cases should be treated as 4-wall or 3-wall defects (Figures 6.3.7 and 6.3.8).

In the aesthetic zone, immediate implant placement is a demanding procedure, given the high prevalence of gingival recession. Only cases with a thick biotype should be selected, and the implant should always be placed palatally and away from the buccal wall, thus creating a vestibular gap to be filled with particulate graft.

When dealing with 2-wall or 1-wall defects, particularly in vertical deficiencies, the technique should be considered advanced and a staged approach is mandatory in most situations. These cases should be handled using onlay grafting or titanium mesh to maintain space (Figures 6.3.9 and 6.3.10).

Determinants to the stability of the grafting area

Determinants to the stability of the grafting area

• The topography of alveolar bone

• The topography of alveolar bone

defects

defects

• The location of bone defects

• The location of bone defects

• The modality of grafting procedure

• The modality of grafting procedure

Figure 6.3.3

Figure 6.3.4

Grafting techniques • Particulate grafting • Block grafting • Reinforcements

Strategy of bone managements one-wall

two-wall

vertical

advanced (staged)

advanced (staged)

dehiscent

advanced (staged)

complex

relatively simple

perforative

complex

relatively simple

relatively simple

circular

three-wall

four-wall

simple simple

To simplify the procedure of bone management!

Figure 6.3.5

Figure 6.3.6

Figure 6.3.7

Figure 6.3.8

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In difficult cases with proper topographies of alveolar ridges, instead of using conventional bone block augmentation, the ridge expansion approach can optimise the grafting conditions and simplify the procedure, transforming a 1-wall defect into a 4-wall defect (Figure 6.3.11 and 6.3.12). Sometimes a ridge split/expansion procedure can be carried out alone to enable implant placement (Figure 6.3.13 and 6.3.14).

Of course there is always the possibility of managing insufficient bone volume prosthetically. Modified

treatment planning for this include: an angled abutment; a cantilever; pink ceramic; and narrow diameter implants.

Paraphrasing the Fourth ITI Consensus, there are specific indications for each technique and the simplest and least risky technique should be chosen.

The classification of bone defects will help with decision-making relating to bone augmentation (Figure 6.3.15).

If in a conventional way

Figure 6.3.9

Figure 6.3.11

Figure 6.3.10

Figure 6.3.13

Crest extension + GBR

Figure 6.3.12

Summary • Every surgical procedure presents speciÞc indications, advantages and disadvantages, which must be carefully evaluated before surgery. It is therefore difÞcult to provide clear indications with respect of which procedures are actually needed.

should be be given given to to those thoseprocedures procedureswhich whichlook looksimpler, simpler, •y Priority The classification of bone defects would help with less invasive, involve less risk of complications, and reach their less invasive, involve less risk of complications, and reach their the decision-making of bone augmentation goals within the the shortest shortest time timeframe. frame. Ñ ITI Consensus Conference 2008

The classification of bone defects would help with the decision-making of bone augmentation Figure 6.3.14

Figure 6.3.15

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Implants in the future: virtual planning, 3D printing and more The virtual patient: how far away are we?

Thabo Beeler Entertainment meets digital dentistry Despite a significant improvement in rendering quality, modelling human faces realistically still remains a challenge for computer graphics. The speaker is a member of the research team at Disney Research Zurich. Working in collaboration with ETH (Swiss Federal Institute of Technology, Zurich) the company has been involved in a research project to acquire and model at high resolution the geometry and appearance of the face. Although the research is mainly aimed at the entertainment industry, it has a direct application in the field of dentistry for developing virtual patients.

Creating a virtual patient is a specialist development of computer graphics that follows a well-known process which can be outlined in five steps: capturing the subject’s geometric data reconstructing the shape of the patient’s face as a computer model manipulating this model simulating the desired changes to be carried out visualising the virtual results This workflow is about to become the state-of-theart in imaging, planning and evaluating treatment for orthodontics, reconstructive dentistry and maxillofacial surgery.

Capturing a high-quality model of the patient’s face Traditional data acquisition systems incorporated artefacts due to their long duration. As a result their accuracy was limited, and in addition the process was complex and the cost was high. The goal of the project in Zurich is to make capturing the 3D geometry of the face with sub-millimetre resolution and fidelity as easy as taking a photograph. A seven-camera system is used to make a singleshot stereoscopic capture. The procedure is called

photogrammetry, a technology that uses two (or more) slightly displaced images of the same object and combines them into one 3D image on the computer. Working with various matching algorithms, the software makes a computer model that is later meshed and refined at different scales.

It is also possible to use this system to capture dynamic information and accurately measure the deformation of skin, for example a subject slapping himself and causing a shockwave in his face.

The system does, however, have its limitations. It works well for the skin, but it is not suited for hair and eyes. In the case of the hair, the hidden episurface is estimated from reconstructed hair that has to be added to the computed model of the skin. The eyes play a central role in the appearance of the face. Their features vary widely, defining the person’s individuality, and this needs to be captured with high fidelity. The proposed system works in three different steps (sclera, cornea and iris) which are combined to the complete eye model.

The acquired skin geometry is accurate to a scale of 100µ. Recently, facial scanning techniques have also been developed using consumer-grade binocular stereo cameras, video cameras and even a smart phone, indicating that the technology is ready to expand beyond the professional domain. It might soon even be possible to obtain a realistic skin mask as a 3D object using the latest-generation 3D printers.

Superimposing CBCT data, intraoral scanning, imaging of the face and brief motion data can create the virtual patient. This enables treatment to be simulated and can help illustrate treatment outcomes to patients. It is an extremely effective communication tool, the extent of whose benefits are yet to be totally identified.

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The origin, present and future of 3D printing Dianne Rekow 3D printing or additive manufacturing is the process of making three dimensional solid objects layer by layer from a digital file. This technology originated in the 1980s with the use of photohardening polymers. The evolution of 3D printing has produced a large number of additive printing processes.

An overview of the different systems reveals that there are fundamentally two families: those that spray materials though some kind of syringe or nozzle, such as fused deposition modelling (FDM), laser engineered net shaping (LENS) and PolyJet those that bind raw materials using laser or adhesion, such as stereolithography (SL), laser sintering (LS) and laminated object manufacturing (LOM) In all cases, the material options are tied to the system type and to date most machines can only handle one class of materials (for example, photopolymers or metals).

The current state-of-the-art An amazing variety of possibilities are now available for fabricating objects. Applications demonstrated include jewellery, engines, body parts, aeroplane parts and even multi-storey apartment buildings.

In dentistry, a wide range of components including

abutments; crowns; metal sub-structures; base plates; guides; splints; and complete or partial dentures can be manufactured using 3D printing. Implants can even be made using sequential layering.

The production process continues to be one-at-atime, at least for most processes, and the machine is the major cost. As a result, 3D printing is carried out almost exclusively in laboratories.

The future of 3D printing 3D printing has the promise to replace the milling machine. If that occurs, it would be prudent to rethink restoration design to capitalise on the structural advantages and intrinsic potential available with this new technology. New materials may need to be developed. Complex geometries – accurate to micrometre dimensions – are now possible. There is still much room for innovation and development, and an array of dental products could be printed chairside in the future. Many children are already learning about 3D printing in school, and this is a field that will generate numerous innovations in the near future. A possible application will likely include being able to deliver the right drugs in the right locations by incorporating them into resorbable scaffolds. The bioprinting of ‘living ink’ is already possible. In the future – in fact in the very near future – it may be possible to incorporate the appropriate cells for organ generation into printed scaffolds.

3D printing in maxillofacial surgery Lawrence Brecht The Jaw-in-a-Day procedure Resection of jaw tumours requires the replacement of bone, soft tissue and teeth. In the mandible, the fibula free flap has become the routine bone reconstructive procedure. But re-establishing adequate facial contours requires proper orthognathic relationships and appropriate dental rehabilitation. These are both major challenges and demand high levels of precision. This precision is hard to achieve freehand, but maxillofacial surgeons can now plan the treatment virtually and transfer it to the surgical field. CAD/CAM technologies can now be used to create highly accurate models, surgical splints, implant placement guides and cutting jigs, and have revolutionised these surgical interventions. Using the previous protocols, dental restoration was delayed for 3 to 6 months, but it can now be performed in one stage. The ‘jaw-in-a-day’ technique has had a significant impact on the field of maxillofacial reconstruction, offering increased accuracy while improving the patient’s function and quality of life.

Virtual surgical simulation and stereolithographic models based on CT scan data allow the

interdisciplinary team to pre-plan the surgical ablation; create selective laser sintered (SLS) cutting guides; and to have an occlusally-designed restoration fabricated digitally prior to surgery.

These measures maximise surgical accuracy during complex reconstructions involving osteotomies; bone segmentation and reshaping; the placement of implants; and occlusal restorations.

In the NYU Langone Medical Center, digital planning and 3D printing has been stimulating a progressive optimisation of template designs.

The current (fourth) generation offer custom reconstruction plates with z-axis control. Although surgeons have less experience of using it in this field, the protocol also works in the reconstruction of the maxilla.

The speaker also described other types of cases which had been treated using these new technologies. These included acquired facial deformities, such as a paediatric patient with osteoradionecrosis who underwent a virtually guided resection of the orbit, along with fibula reconstruction and adhesive prosthesis. Other cases

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involving the replacement or reconstruction of the nose or ear have been successfully addressed using virtual planning and prostheses made by 3D

printing. Finally, the author talked about his early experience of these techniques when applied to face transplantations.

3D printing in prosthodontics Vincent Fehmer and Irena Sailer Why 3D printing in prosthodontics?

Early CAD/CAM systems relied almost exclusively on milling a restoration out of prefabricated blanks of different materials. This kind of subtractive fabrication accurately creates the desired shape, although at the expense of time, high cost and with almost 90% of the material wasted.

3D printing is a rapidly emerging additive technology that is gradually changing the manufacturing protocol for dental prosthodontics.

A variety of components are now being made using 3D printing . These include surgical guides; wax patterns for fixed/removable prostheses; moulds for metal or ceramic processing; metal or ceramic frameworks; and maxillofacial prostheses.

3D printing is becoming the preferred process as it offers a range of advantages compared with subtractive alternatives: it has improved accuracy1 and doesn’t induce micro cracks it offers improved efficiency, both in terms of cost and time less raw material is wasted and there is less wear/ abrasion of cutting tools

1 Örtorp et al. The fit of cobalt-chromium three-

unit fixed dental prostheses fabricated with four different techniques: A comparative in vitro study.

Dent Mater. 2010; 27(4:356–63)

it has the capacity to reproduce complex geometries with cavities and undercuts, with highly predictable outcomes Digital diagnostics and 3D printing The ‘digital workflow’ begins with the capturing of digital intraoral scans and continues with the creation of virtual diagnostic setups from which high-resolution diagnostic models can be printed.

Conventional mock-ups are an efficient tool for communication with the patient, helping to anticipate results and offering enhanced opportunities to obtain informed consent for the treatment before it commences. But creating these conventional mock-ups is a time-consuming procedure that results in only a single version of the possible treatment outcome. Digital mock-ups using 3D diagnostic digital wax-ups or set-ups can be straightforwardly printed out of resin, and enable the try-in of multiple possible treatment solutions (Figures 7.4.1–7.4.4).

Final reconstructions and 3D printing It is now increasingly practical to fabricate a variety of final restoration parts – such as copings, crowns and frameworks for fixed and removable prostheses – using 3D printing technologies. A typical workflow involves planning implant placement using data captured from the 3D CBCT, followed by the creation of a 3D-printed surgical guide, then the adaptation of the provisional bridge printed out from the same file during the surgery (Figures 7.4.5–7.4.7).

Digital diagnostics & 3D printing conventional impression

Digital diagnostics & 3D printing

optical impression

Advanced smile diagnostics using CAD/CAM mock-ups; M Sancho-Puchades, V Fehmer, CHF Hämmerle, I Sailer, The Inernational Journal of esthetic dentistry 07/2015;10(3):374-391

Figure 7.4.1

Advanced smile diagnostics using CAD/CAM mock-ups; M Sancho-Puchades, V Fehmer, CHF Hämmerle, I Sailer, The International Journal of esthetic dentistry 07/2015;10(3):374-391

Figure 7.4.2 Digital diagnostics & 3D printing

Advanced smile diagnostics using CAD/CAM mock-ups; M Sancho-Puchades, V Fehmer, CHF Hämmerle, I Sailer, The International Journal of esthetic dentistry 07/2015;10(3):374-391

Figure 7.4.3

Digital diagnostics & 3D printing

Advanced smile diagnostics using CAD/CAM mock-ups; M Sancho-Puchades, V Fehmer, CHF Hämmerle, I Sailer, The International Journal of esthetic dentistry 07/2015;10(3):374-391

Figure 7.4.4

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3D printing can also be harnessed for the fabrication of metal structures, either indirectly by creating burn-out resins or waxes for lost-wax processes, or directly by printing using metals or metal alloys.

Although still in development, ceramic printing is an emerging procedure which can be used to make monolithic crowns and frameworks.

The ‘virtual patient’ The speaker described her involvement in the previously cited research project involving ETH

Zurich, the University of Zurich and Disney Research to develop a 3D face scanning system tailored for medical applications (Figure 7.4.8). The ‘virtual patient’ consists of a merged dataset from CBCT, intraoral scans and facial scan files. Successful development of virtual patient models opens up the possibility of virtual diagnostics; printed try-in tools; guided treatment (surgical guides, preparation guides); digital colour assessment; and printed final reconstructions.

New Methods and Materials in todays treatment concepts

New Methods and Materials in todays treatment concepts

Cerec OmniCam

Figure 7.4.5

Vita Enamic

Figure 7.4.6

The future of 3D in prosthodontics

Final reconstructions & 3D printing utilizing new technologies

ETHZ: Mörzinger R, Solenthaler B,Wu C, Gross M UGE: Sailer I Private practice: Lübbers T Disney Research Zurich: Beeler T

Figure 7.4.7

Figure 7.4.8

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Consensus Conference 2015 What is a consensus conference and how is it organised?

The EAO held its 4th Consensus Conference in Switzerland from 11–14 February 2015. This brought together experts in implant dentistry from across the world to discuss a range of key topics. After the conference, the findings were published in a supplement of Clinical Oral Implants Research.

The process for the 2015 conference began with the appointment of the three chairs who would organise it, namely Björn Klinge, Christoph Hämmerle and Marc Quirynen. They then identified an international group of scientists and practitioners to collectively recommend potential topics to be discussed at the conference. Having approved the list of topics, the committee selected the reviewers and participants (experts on individual topics) and formed four working groups.

The second step consisted of scrutinising the literature published on each topic in a systematic way to identify relevant scientific papers that related to each subject. These reviews were circulated to participants to be read before the meeting.

Once all the participants were face to face at the conference, the meeting was structured around four working groups and two types of sessions. During the work sessions, members of each of the four groups prepared draft conclusions on the topics they were examining. In the regular plenary sessions, all participants came together to discuss/agree

these drafts and work towards developing the final consensus statements.

Why is it important?

The field of implant dentistry has been almost overwhelmed by very rapid changes as new protocols, materials and strategies emerge. The research community does its best to respond as rapidly as possible to these new developments in order to assess their safety and efficacy.

Unfortunately, the evidence gathered is often not optimal, either in terms of quantity or quality.

Problems can arise if sample sizes are too small; there is an absence of long-term evidence relating to efficacy; or there is bias in the study. As a result, there is a need for guidance on which procedures are appropriate in which cases. The EAO tries to bridge this gap between research and clinical practice through its Consensus Conferences.

Why the EAO Consensus Conference is unique Much of the research available to practitioners is led or sponsored by industry, and it is often difficult to distinguish information that may be biased from independent research. Findings from events like the EAO consensus conference, which receives no industry funding whatsoever, provide valuable independent perspectives and conclusions which are not influenced by commercial interests.

The findings of all the EAO’s Consensus Conferences, including the 2015 conference, are available with open access from http://www.eao.org/consensus-paper

The patient undergoing implant therapy Group 1 (speaker: Thomas Flemmig) Perioperative antibiotics in conjunction with dental implant placement With the aim of assessing the effect of antibiotic prophylaxis on implant survival in conjunction with dental implant placement, an extensive review yielded 7 systematic reviews and 9 primary clinical trials. The result was a 2% overall reduction in risk of implant loss when using antibiotic prophylaxis compared with placebo (Figure 8.1.1).

The value of this modest figure must be put in the context of the growing problems with antibiotic resistance before antibiotic prophylaxis is adopted as a guideline. The final consensus conclusion was that antibiotic prophylaxis is not recommended in uncomplicated cases and healthy patients. In complicated cases, the beneficial effect can not be excluded.

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Risk indicators for peri-implantitis The existing evidence identifying risk indicators for peri-implantitis was reviewed in MEDLINE up to October 2014. It can be clearly stated that periimplant plaque accumulation is the cause that triggers the inflammatory response leading to periimplant mucositis/peri-implantitis. A complex microbiota has been demonstrated to be involved in the process. There is overwhelming evidence that smokers and patients with a history of periodontal disease have an increased risk of developing periimplantitis. There is also some evidence to support the role of genetic polymorphism, diabetes, and excess cement as risk indicators for the disease.

As a consequence, regular maintenance care and treatment of periodontitis prior to implant placement must be strongly recommended (Figure 8.1.2).

The current use of patient-centred/-reported outcomes in implant dentistry The aim of this review was to provide an update on the use of Patient-Reported Outcome Measures (PROMs) in implant dentistry and to compare PROMs for implant-supported prostheses with alternative treatment options or a healthy dentition (Figure 8.1.3). The search (up to December 2014) yielded 635 publications, 300 of which had been published in the last 6 years. 84 controlled studies could be identified, including 38 RCTs and 31 cohort studies.

The authors feel there is an urgent need for standardised reporting of PROMs in the field of implant dentistry. There is plenty of evidence that patients with a fully edentulous mandible experience higher satisfaction with an implantretained overdenture when compared with a conventional denture. The PROMs were not

affected either by the number of implants, or by the attachment system. Although individual perceptions may vary widely, in the maxilla no major difference in patient satisfaction was seen. There were insufficient data to compare PROMs relating to overdentures with fixed prostheses or to draw conclusions from partially edentulous patients. Nor did the timing of implant placement have any effect on PROMs. Economic evaluation of implant-supported prostheses Economic evaluations measure the efficiency of different healthcare interventions and can provide useful information for decision-making. Costeffectiveness analysis relates measures of outcome to treatment costs and is most valuable for assessing interventions that are more effective and cost more than their alternatives, in terms of incremental costeffectiveness ratios (ICERs) (Figure 8.1.4).

Various clinical scenarios were analysed and the following conclusions drawn: for central incisors with irreversible pulpitis and coronal lesions root canal treatment was the most cost-effective treatment option for replacing a single missing tooth, an implantsupported crown seems to be more cost-effective that a fixed bridge for the edentulous mandible, overdentures improved oral health-related quality of life, but cost more than conventional dentures for molars with furcations, periodontal therapy was found to be more effective and less costly than implant-supported single crowns, but this finding may need to be interpreted with caution

EAO Consensus Conference 2015

EAO Consensus Conference 2015

The Patient Undergoing Implant Therapy

Group 1

General conclusions from the paper and Group’ s consensus Antibiotic prophylaxis - 2% overall reduction in risk of implant loss - NNT 50 Uncomplicated cases and healthy patients - No benefit - Not recommended Complicated cases - Beneficial effect cannot be excluded

Perioperative Antibiotics in Conjunction with Dental Implant Placement. Complex Systematic Review Lund B, Hultin M, Tranaeus S, Naimi-Akbar A, Klinge B Clin Oral Impl Res 26(Suppl. 6) 2015

Figure 8.1.1

Group 1

The Patient Undergoing Implant Therapy

General conclusions from the paper and Group’ s consensus (cont.)

Preventive - Treatment of periodontitis - Regular maintenance care

Risk Factors for the Development of Peri-implantitis. A Narrative Review Renvert S & Quirynen M Clin Oral Impl Res 26(Suppl. 6) 2015

Figure 8.1.2

EAO Consensus Conference 2015 Group 1

EAO Consensus Conference 2015

The Patient Undergoing Implant Therapy

EAO Consensus Conference 2015 Group 1

Aim of the review

Material & Methods

Patient reported outcome measures (PROMs) - In implant dentistry - Implant-supported prostheses vs. alternative treatments

MEDLINE and Cochrane Library Until December 2014

The Patient Undergoing Implant Therapy Cost

Costs more Less effective

Costs more More effective ICER Effectiveness

Cost-minization analyses (CMA) Cost-effectivenes analyses (CEA) Cost-benefit analysis (CBA)

Costs less Less effective

Costs less More effective

Adapted from Higgins et al. 2012 Current Use of Patient Centered/Reported Outcomes in Implant Dentistry: A Systematic Review De Bruyn H, Raes S, Matthys C, Cosyn J Clin Oral Impl Res 26(Suppl. 6) 2015

Figure 8.1.3

Economic Evaluation of Implant-supported Prosthesis. A Narrative Review Beikler T & Flemmig TF Clin Oral Impl Res 26(Suppl. 6) 2015

Figure 8.1.4

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Digital technologies to support planning, treatment, and fabrication processes and outcome assessments in implant dentistry.

Group 2 (speaker: Christoph Hämmerle) Computer-supported implant planning and guided surgery The literature search aimed to provide an overview of computer-supported implant planning and guided surgery from examination to planning and execution, including possible errors and pitfalls, in order to justify the indications for guided surgery.

The conclusions are: guided implant surgery clearly reduces inaccuracy as compared with freehand surgery the accuracy obtained when following guided implant surgery protocols increases the possibility of delivering an ideal final reconstruction transferring the implant planning data to the operative field remains the most difficult part tooth-supported guides render the highest accuracy and mucosa supported guides offer higher accuracy than bone supported guides (Figure 8.2.1) future improvements may come from reducing the steps needed for guided surgery if the predictability of the treatment can be increased, the number of clinical implications can be further expanded as guided surgery adds precision to flapless surgery, it has implications in geriatric as well as medically compromised patients

stress reduction in the operating room as a result of guided surgery may be a considerable additional benefit computed tomography (CT) does not offer advantages over cone beam computed tomography (CBCT) regarding guided implant surgical procedures the clinical situations and the categories of patients who benefit the most from guided surgery should be identified more clearly CAD/CAM-fabricated implant-supported restorations Having identified and summarised the available literature related to CAD/CAM-fabricated implantsupported restorations, promising short-term results have been observed (Figure 8.2.2). Overall, the current evidence is quite limited due to the quality of studies and the paucity of data on long-term clinical outcomes.

Digital technology is used for the design and manufacture of implant prosthetic components, specifically for abutments, crown and bridge frameworks and associated veneers. Clinical feasibility has been demonstrated for most of them, offering technical, clinical and procedural benefits.

No information is presently available on monolithic

EAO Consensus Conference 2015 Group 2

Digital technologies

General conclusions from the paper

The findings of all the EAO’s Consensus Conferences, including the 2015 conference, are available with open access from http://www�eao�org/consensus-paper

• Tooth supported guides render the highest accuracy • Mucosa supported guides offer higher accuracy than bone supported guides

Computer-supported implant planning and guided surgery Marjolein Vercruyssen, Isabelle Laleman, Reinhilde Jacobs, Marc Quirynen Clin Oral Impl Res 26(Suppl. 11) 2015: 69-76

Figure 8.2.1

EAO Consensus Conference 2015 Group 2 General conclusions from the paper • Overall, the current evidence in the literature is quite limited, but short-term results are promising • Publications on single crowns and FDPs are very few • 10 papers on full-arch screw-retained FDPs reported survival rates ranging 92% – 100% during observation times of 1–10 years.

CAD/CAM-fabricated implant- supported restorations Sebastian Berthold Maximilian Patzelt, Benedikt C Spies, Ralf J Kohal Clin Oral Impl Res 26 (Suppl. 11) 2015: 77-85

Figure 8.2.2

EAO Consensus Conference 2015 Group 2

Digital technologies

Digital technologies

General conclusions from the paper • Recent technological progress has provided useful tools for assessing outcomes of oral rehabilitation with dental implant including the following techniques: -

Cone-beam computed tomography Magnetic resonance imaging Ultrasonography Optical scanning Optical coherence tomography Spectrophotometry.

Novel digital imaging techniques to assess the outcome in oral rehabilitation with dental implants Goran Benic, Moustafa Elmasry, Christoph Hammerle Clin Oral Impl Res 26 (Suppl. 11) 2015: 86-96

Figure 8.2.3

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reconstructions made entirely using CAD-CAM procedures.

In many clinical situations, computer-aided reconstructive dentistry can offer specific benefits relating to standardisation and data acquisition, communication tools, and industrialised fabrication with a reduction in time, efforts and costs.

But there are important research implications: the rapid development of CAD-CAM technologies has added a multitude of new parameters to be tested, and researchers have to identify the most relevant clinical questions and the appropriate control groups.

From the point of view of evidence-based dentistry, the authors recommend further studies designed as randomised controlled clinical trials and reported according to the CONSORT statement.

Novel digital imaging techniques to assess the outcome in oral rehabilitation with dental implants Diverse digital imaging devices (Figure 8.2.3) have recently been introduced allowing precise and reproducible assessment of implant-related outcome parameters, and therefore a standardisation of the results.

Optical scanning is being used for the 3D assessment of changes in the soft tissue contour. The combination of an optical scan with preoperative CBCT allows the determination of the implant position and its spatial relation to anatomic structures.

Spectrophotometry is commonly used to assess the colour match of prostheses and peri-implant mucosa to natural dentition and gingiva.

When available, multiple patient-related data sets (eg CBCT, intraoral and laboratory scans, virtual planning of implants and restorations) should ideally be integrated to maximise their synergistic diagnostic value: the so called ‘virtual patient’.

Regarding research on this subject, there is a need for validation and standardisation of the majority of the novel digital imaging techniques and dedicated software. At the same time, computer algorithms have to be improved to enable accurate matching of different 3D data sets (eg facial scan and CBCT) and integration into specific software. Research is required to validate these novel methods before they are used in daily clinical practice.

Soft and hard tissue aspects.

Group 3 (speaker: Alberto Sicilia) Soft tissue augmentation around dental implants: its impact on soft and hard tissue stability The systematic review prepared by this group aimed to answer the following question: ‘What is the longterm effect of soft tissue augmentation procedures around dental implants with respect to the soft and hard tissue stability?’.

Articles on peri-implant soft tissue augmentation were systematically searched for, with only prospective studies with at least 10 patients and 1 year of follow-up included. Of 4,327 articles identified, 47 were read in full and 10 were finally selected: 2 RCTs, 5 CCTs and 3 prospective clinical studies.

The outcome variables considered for analysis were:

peri-implant attached/keratinised tissue width peri-implant soft tissue changes peri-implant marginal soft tissue level changes peri-implant marginal bone level changes aesthetics, evaluated by patients aesthetics, evaluated by dentists

The general conclusion of the review was that there is no long-term evidence for whether augmented soft tissues can be maintained over time and are able to influence peri-implant bone levels. But over shorter observation periods, some limited evidence can be identified:

tissue grafting is able to increase the peri-implant soft-tissue thickness and the width of keratinised tissue (Figure 8.3.1) in posterior mandibular areas with thin crestal tissue, marginal peri-implant bone loss may be reduced by means of vertical soft tissue thickening procedures (Figure 8.3.2) only two 1-year case series studies were appropriate for meta-analysis, and showed a reduction of 1.65 ± 0.01 mm in marginal recession after peri-implant plastic surgery (Figure 8.33) subjective and objective aesthetic results may also be improved by soft tissue augmentation techniques (Figures 8.3.4 and 8.3.5) Group’s consensus statement: There are clear indications for the use of soft tissue grafts to improve the peri-implant tissue situation as well as the aesthetics. However, we have to bear in mind that there is no long-term evidence to strongly recommend peri-implant soft tissue augmentation procedures. The decision must at this stage be left to the clinician’s judgement after a thorough patient evaluation.

Long-term outcomes of bone augmentation on soft and hard tissue stability The review analysed the current literature regarding medium- and long-term data concerning the stability of peri-implant tissues after hard tissue augmentation prior to or at the same time as implant placement.

some clinical data seems to support the theory that soft tissue augmentation based on connective

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The search focused on prospective clinical studies assessing peri-implant bone and soft tissue stability over time, with a minimum follow-up of 12 months and a sample of at least 10 patients. From 1,687 articles yielded by the electronic search, 37 met the inclusion criteria, of which 10 were RCTs and 27 were CCTs. Taken together, the studies evaluated 274 implants in 230 patients.

Great heterogeneity was observed in the studies regarding the materials and techniques used for augmentation, as well as the methods used for evaluation. The outcome variables analysed were: mean marginal interproximal bone loss (periapical Rx’s) 3D evaluation by CBCT examination (three studies) soft tissue recession (periodontal probing or calibrated photographs) soft tissue dimensions with radiopaque markers (CBCT) Having reviewed all the studies, it can be concluded that there is limited information regarding both stability of the soft tissue and the underlying regenerated bone. However, some studies on simultaneous GBR procedures show significant bone gain and a positive relationship between the two tissues over a medium-term period (Figure 8.3.7).

One study using CBCT evaluation found absent buccal hard tissue at 7 years in 36% of implants, leading to a pronounced soft tissue recession.

However, GBR augmentation associated with immediate implant placement may not be recommendable, as further bone loss of the buccal plate may occur (Figure 8.36).

There is a lack of data about the medium- to long-term stability of augmented bone using surgical techniques other than GBR, although stability has been reported in the short-term with techniques using autogenous bone, with or without deproteinised bovine bone mineral, and titanium mesh or fibrin glue acting as stabilisers of the graft (Figure 8.3.8).

The effect of zirconia or titanium as abutment materials on peri-implant soft tissues The aim was to analyse research with regard to the effect of zirconia or titanium as abutment materials on peri-implant soft tissues. To this end, a search was made of articles showing a direct comparison of both types of abutment material in the same patient.

The inclusion criteria include a sample of at least 10 patients, a follow-up of at least 1 year and reporting on at least one of the outcome measures. Of 454 initial results, 11 met the inclusion criteria: 4 RCTs and 7 CCTs.

EAO Consensus Conference 2015

EAO Consensus Conference 2015

Group III Group’s Consensus 1.- Soft tissue augmentation procedures are able to increase the periimplant soft tissue thickness and the width of keratinized tissue.

Group III Group’s Consensus 2.- In posterior mandibular areas with thin crestal tissue, marginal periimplant bone loss may be reduced by means of vertical soft tissue thickening procedures.

1.2 mm 1.6 mm

Long-term stability of peri-implant tissues after bone or soft tissue augmentation. Effect of Zirconia or titanium abutments on peri-implant soft tissues. Consensus Report of Group 3.

Sicilia A, Quyrinen M et al. Clin Oral Impl Res 26 (Suppl. 11) 2015.

Figure 8.3.1

Long-term stability of peri-implant tissues after bone or soft tissue augmentation. Effect of Zirconia or titanium abutments on peri-implant soft tissues. Consensus Report of Group 3.

Sicilia A, Quyrinen M et al. Clin Oral Impl Res 26 (Suppl. 11) 2015.

Figure 8.3.2

EAO Consensus Conference 2015

EAO Consensus Conference 2015

Group III Group’s Consensus 2.- In posterior mandibular areas with thin crestal tissue, marginal periimplant bone loss may be reduced by means of vertical soft tissue thickening procedures.

Group III Group’s Consensus 3.- The coverage of exposed implant/abutment surfaces related to shallow marginal soft tissue recessions may be achieved by means of CAF+CTG.

Full Coverage 65% -1.8 mm -0.3 mm

Mean Coverage 92%

-1.1 mm -0.2 mm

Figure 8.3.3

1.5 mm 1.7 mm

Figure 8.3.4

The findings of all the EAO’s Consensus Conferences, including the 2015 conference, are available with open access from http://www�eao�org/consensus-paper Congress Scientific Report: EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

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EAO Consensus Conference 2015

EAO Consensus Conference 2015

Group III Group’s Consensus 4.- Subjective and objective aesthetic results may be improved by means of soft tissue augmentation procedures.

(Pat) p<0.01 (Dent) p<0.001 (Dent) p<0.0001

Group III Stability of the augmented bone: Only one study (CCT) examined the use of GBR techniques simultaneously with implant placement, immediately after tooth extraction. This paper reported that at 7 years and 36% of the implants treated showed almost a non-detectable buccal plate.

(Benic et al 2012).

Long-term tability of peri-implant tissues after bone or soft tissue augmentation. Effect of Zirconia or titanium abutments on peri-implant soft tissues. Consensus Report of Group 3.

Sicilia A, Quyrinen M et al. Clin Oral Impl Res 26 (Suppl. 11) 2015.

Figure 8.3.5

Figure 8.3.6

EAO Consensus Conference 2015

EAO Consensus Conference 2015

Group III Clinical recommendations: Consistent bone ridge reconstructions obtained by means of GBR procedures may facilitate the maintenance of a stable buccal soft tissue contour.

Post GBR

Implants & Provisional Prostheses

Group III Clinical recommendations: There is a lack of information about threedimensional hard and soft tissue evolution following the use of other kinds of hard tissue augmentation techniques.

2 years follow-up

Long-term tability of peri-implant tissues after bone or soft tissue augmentation. Effect of Zirconia or titanium abutments on peri-implant soft tissues. Consensus Report of Group 3.

Sicilia A, Quyrinen M et al. Clin Oral Impl Res 26 (Suppl. 11) 2015.

Figure 8.3.7

The outcome variables considered were: biological: pocket probing depth (PPD); bleeding on probing (BOP); soft tissue recession (REC); marginal bone level (MBL); and biological complications aesthetic: soft tissue colour; aesthetic patientreported-outcome; and objective aesthetic evaluation

Long-term tability of peri-implant tissues after bone or soft tissue augmentation. Effect of Zirconia or titanium abutments on peri-implant soft tissues. Consensus Report of Group 3.

Sicilia A, Quyrinen M et al. Clin Oral Impl Res 26 (Suppl. 11) 2015.

Figure 8.3.8

The consensus statement: no significant differences were seen in clinical outcomes in terms of PPD, BOP, MBL and mucosal recessions when comparing zirconia and titanium as abutment materials. Zr abutments may be associated with more biological complications, whereas they showed significant superiority in achieving natural soft tissue colour.

Therapeutic concepts and methods for improving dental implant outcomes� Group 4 (Speaker: Mariano Sanz) Short implants versus sinus lifting with longer implants to restore the posterior maxilla The focused question of this paper was: ‘Are short implants superior to longer implants in the augmented sinus in terms of survival and complication rates of implants and reconstructions, patient-reported outcome measures (PROMs) and costs?’

To answer this question a systematic literature search was performed with the objective of supporting the clinician in the decision-making process and providing information to the patient about both procedures. 8 RCTs were selected from an initial search of 851 titles. The results were as follows: survival rates were similar for both longer and shorter implants

crestal bone levels measured radiographically (reported by only three studies) did not show significant differences between the two therapeutic options complications were predominantly of biological origin; mainly occurred intraoperatively as membrane perforations; and were almost three times more frequent for longer implants in the augmented sinus compared with shorter implants with regard to PROMs, morbidity, surgical time and costs, the results were in favour of shorter implants Conclusion: Given the higher number of biological complications, increased morbidity, costs and surgical time involved in placing longer implants in the augmented sinus, shorter implants may represent the preferred treatment alternative.

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Short implants compared to implants in vertically augmented bone Focused question: ‘Are short implants comparable to longer implants placed in vertically augmented bone in terms of survival and complication rates of implants and reconstructions, radiographic bone levels, and patient-reported outcome measures (PROMs)?’

The interventions considered were: short implants (≤ 8 mm) supporting fixed restorations longer implants (> 8 mm) supporting fixed restorations After identifying 3,387 titles initially, only 4 fulfilled the inclusion criteria. The 4 RCTs with follow-up of between 1 and 5 years reported similar high implant survival rates for both groups of interventions (95.1% vs. 96.2%). Fewer surgical complications were observed when using short implants vs implants placed in vertically augmented bone (56% of patients with temporary nerve paresthesia, compared with 17% respectively). There were similar crestal bone level changes (1.51 mm vs. 1.23 mm, respectively).

These results must be interpreted with caution as all studies were performed by the same research group and the quality assessment was ranked as having a high risk of bias. Well-designed RCTs to properly compare long-term (> 5 years) success are needed.

The group’s consensus was that vertical ridge augmentation is the preferable option when the available bone is less than the available implant length. When the bone available is between 5mm and 8 mm, both short implants and vertical augmentation are valid therapeutic options, although the latter requires a favourable anatomical site (bone availability and shape, patient’s mouth aperture, surgical access conditions, etc.). Patient factors such as general health conditions, habits and preferences may favour the short option.

Does ridge preservation following tooth extraction improve implant treatment outcomes Alveolar ridge preservation, also known as ‘socket preservation’, involves any procedure developed to limit post-extraction resorption and maintain the soft and hard tissue contour of the ridge. Different types of procedures have been described in the literature, including guided bone regeneration (GBR), socket filler and socket sealing. For the time being there is a lack of consensus as to whether alveolar ridge preservation, in comparison with unassisted socket healing, directly improves implant-related outcomes such as:

improved survival/success rates and marginal bone loss of implants Furthermore, no biomaterial or type of intervention used for alveolar ridge preservation can be claimed to be superior than others in terms of implant outcomes.

Therefore, the aim of this systematic review and meta-analysis was to investigate the following: 1. The additional effect of alveolar ridge preservation on implant-related outcomes in comparison with unassisted socket healing 2. To estimate the extent/dimensions of the abovementioned outcomes according to the type of intervention (socket filling, socket seal, GBR) Regarding the feasibility to place implants, the investigation yielded similar results for alveolar ridge preservation compared with unassisted socket healing. Survival rates were similarly high in both groups. Significant differences appeared in the additional ridge augmentation needed at the time of implant placement (7/111 vs. 50/103), with a relative risk of 0.15 (0.07–0.3).

Within the limitations of present study, the following conclusions can be drawn: 1. Alveolar ridge preservation procedures may decrease the need for further ridge augmentation during implant placement in comparison with unassisted socket healing 2. There is no evidence to support the fact that implant placement feasibility is increased following alveolar ridge preservation in comparison with unassisted socket healing 3. The survival, success and marginal bone levels of implants placed in alveolar ridges following alveolar ridge preservation are comparable to those of implants placed in untreated sockets 4. No evidence was identified regarding the possible superior impact of a particular type of intervention (GBR, socket filler and socket seal) on implant outcomes. It is not currently known if one particular biomaterial or treatment protocol is superior to another 5. The majority of studies evaluating implantrelated outcomes after ARP procedures present a high or unclear risk of bias; therefore, any clinical recommendation derived from these studies should be applied with caution The findings of all the EAO’s Consensus Conferences, including the 2015 conference, are available with open access from http://www.eao.org/consensus-paper

improved implant placement feasibility reduced need for further augmentation during implant placement

The findings of all the EAO’s Consensus Conferences, including the 2015 conference, are available with open access from http://www.eao.org/consensus-paper Congress Scientific Report: EAO 24th Annual Scientific Meeting Stockholm, 24–26 September 2015

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Successful supportive treatment – evidence for clinical efficacy The clinical outcome of implant treatment has to be judged over the long-term, with the main objective of success being benefit to the patient. With this in mind, it is disturbing that levels of peri-implant inflammation appear to be extremely high. This has the potential to become a significant area of concern for public health in the growing population that has been treated with dental implants.

Addressing this problem will involve developing standardised supportive treatment that can be applied universally. At the moment, this approach seems to offer the only effective way of preventing the biological problems that have been associated with oral osseointegration.

This session described some of the available evidence relating to this serious problem: Hugo De Bruyn provided a comprehensive update on peri-implantitis, including its diagnosis, prevalence and preventive measures for each of the factors involved Lisa Heitz-Mayfield discussed the practical steps involved in supportive care for implant patients.

Evidence for the efficacy of supportive peri-implant therapy following treatment of peri-implant disease was also presented Mariano Sanz focused on the options available to prevent these problems from occurring, looking at the issue from primary, secondary and tertiary perspectives

Peri-implantitis: diagnosis and prevention through case selection and proper treatment execution Hugo De Bruyn Having begun by emphasising the significance of peri-implantitis, the speaker continued with a description of the condition based on the four interfaces where it occurs. He described how the pathogenic factors interact with bone, soft tissue, the abutment and the restoration (Figure 9.1.1).

Contamination of implant sites by oral microorganisms has been clearly demonstrated, as has the pathogenic contribution of the oral biofilm, although opinion differs as to whether this is a primary cause of peri-implantitis, or instead contributes to a secondary infection of the local pathological environment.

The adaptive bone loss that follows the early establishment of biological width must be clearly distinguish from peri-implantitis. In order to make this distinction, a baseline is required so that the progression of bone loss can be compared and a diagnosis of peri-implantitis made, if appropriate (Figures 9.1.2 and 9.1.3). As previously described in systematic reviews, the prevalence of

peri-implantitis can be considered to vary widely depending on the chosen diagnostic criteria.

At bone level, the implant surface appears to be a possible predisposing factor. Based on recent studies, an association exists between roughness and periimplantitis, although this should not be considered as a simple and direct pathogenic mechanism (Figures 9.1.4 and 9.1.5). A recent long-term study with a mean follow-up of 15 years indicated an incidence of 4.1% for peri-implantitis and concluded that implant treatment in the edentulous jaw has a predictable long-term outcome with limited complications.1 Next, the speaker described the relationship between crestal bone and abutment height (Figures 9.1.6 and 9.1.7). He discussed the need for a certain degree of soft tissue thickness to protect the tissue-implant interface. He also described the failure to leave enough bone around the implant when placing it 1 Vandeweghe et a. Clin Oral Impl Res 2015;00:1–6

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as a risk factor for bone loss. Problematic situations included location of the implant too close to the vestibular wall; inappropriate diameter of either the implant or abutment; and compromised morphology of the residual bone. These scenarios have the potential to lead to adaptive bone loss, rather than peri-implantitis itself.

With regard to bone, the speaker raised an interesting issue that requires further discussion: would grafted bone eventually lead to peri-implantitis? And in a more general way, would initial bone loss lead to periimplantitis? (Figure 9.1.8)

He concluded by saying that peri-implantitis is a complex condition with multiple predisposing factors. Understanding each one is important in order to prevent the subsequent development of the disease.

Peri-implantitis: myth, hype or evidence

Peri-implantitis: myth, hype or evidence

Interfaces

Turning to the patient factor, he noted that periodontitis and smoking have been unquestionably demonstrated as predictors for peri-implantitis, while cement remnants have been identified as restorative factors that can lead to peri-implantitis.

niches – gaps – reservoirs

Crestal bone remodeling   

10% of the individual implants have a bone level position 2 mm below abutment-implant interface already initially 20% lost above 2 mm in total after 3 years Less than 5% increased over time = bone loss = possibly peri-implantitis

3,0

Based on mean bone loss <0.2 mm yearly -> no peri-implantitis

2,5

10%

20%

2,0

Albreksson & Isidor

Quintessence 1993; 365-369

Based on 2 mm additional bone level reduction (from the expected and after 1 year) -> peri-implantitis is less than 10%

1,5

Sanz & Chapple JCP 2012; 39 (Suppl 12); 202-206

1,0

Based on any bone loss with or without pocketing -> periimplantitis is much higher

0,5

0,0 initial

3 months

12 months

24 months

36 months

Zitzman & Berghlundh JCP 2008; 35 (Suppl):286-291

De Bruyn & Collaert COIR 2008; 19:717-23

Figure 9.1.1

Figure 9.1.2

 A results of an imbalance between the bacterial challenge and the host respons.  Imbalance may affect only the peri-implant mucosa without bone loss = peri-implant mucositis  According to the European workshop criteria peri-implantitis is characterised by mucosal inflammation with additional bone loss after the first year of loading including increasing pocket depth and bleeding or suppuration

 It is not specified how much bone loss !

Baseline missing

Peri-implantitis: myth, hype or evidence

 Peri-implant disease following successful integration

Peri-implantitis: myth, hype or evidence

Peri-implantitis: myth, hype or evidence

Diagnosis of peri-implantitis

Peri-implantitis PeriPeri implantitis: moderately rough or machined surfaces

 36 patients with 218 Southern Implants  Mean follow-up:161 months (SD 52) [48-252]  Bone level: 1.57 mm

Crestal bone loss associated with abutment height

Peri-implantitis ? YES



CBL may occur for reasons other than infection

Lindhe et al. JCP 2008; 35 (suppl. 8):282-285

Figure 9.1.4

21 years

 Probing depth: 3.61 mm

Vandeweghe et al. COIR 2015 Apr 9 [Epub ahead of print]

Figure 9.1.5

Peri-implantitis: myth, hype or evidence

Peri-implantitis PeriPeri implantitis: moderately rough or machined surfaces  34.9% = turned surface (Sa 0.7)  65.1% = modified surface (Sa 0.7-1.2)  No significant difference  bone loss [median & mean] is equal  All outlyers are in the moderately rough group

2.4 mm

10%

25%

Abutment height, reflecting soft tissue thickness, affects CBL

Vandeweghe et al. COIR 2015 Apr 9 [Epub ahead of print]

Figure 9.1.6

Mean bone loss ranges from 0.2 to 1.2 mm Abutment height reflecting soft tissue thickness Ranging from 4 -1 Abutment affects CBP

   

Abutment Bone loss 1 mm => 1.2 mm 2 mm => 1.1 mm 3 mm => 0.4 mm 4 mm => 0.2 mm

Figure 9.1.7 Peri-implantitis: myth, hype or evidence

Peri-implantitis: myth, hype or evidence

Crestal bone loss associated with abutment height

Bone condition and peri-implantitis risk  Regenerative procedures with biomaterials are wide spread mainly for aesthetic purposes  What is the risk of this bone condition to induce future peri-implantitis

S. Vervaeke, M. Dierens, J. Besseler & H. De Bruyn . The influence of initial soft tissue thickness on peri-implant bone remodeling Clin. Impl.. Dent Rel Res. Clin Implant Dent Relat Res. 2014; 16:238-47.

Biomaterial

Socket preservation

S. Vervaeke, M. Dierens, J. Besseler & H. De Bruyn . The influence of initial soft tissue thickness on peri-implant bone remodeling Clin. Impl.. Dent Rel Res. Clin Implant Dent Relat Res. 2014; 16:238-47.

Figure 9.1.8

Figure 9.1.9

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Supportive therapy following treatment of peri-implant disease Lisa Heitz-Mayfield The speaker began with an overview about supportive therapy, including its goals; the recommended frequency and protocols; the supporting evidence; and patient compliance.

Even though it has been well documented through comparative studies that the absence of maintenance (a lack of patient compliance and poor plaque control) is associated with a high incidence of periimplantitis, an acceptable standard of supportive therapy is rarely described. Few studies include an in-depth description of the protocol for supportive therapy used in their materials and methods, despite the fact that this is a key factor to long-term success.

The speaker reviewed the most relevant studies addressing supportive therapy and 5-year implant outcomes and presented studies that followed patients receiving supportive therapy following treatment of peri-implantitis.

Compliance with supportive therapy is an important factor in achieving good long-term results. It has been correlated with lower complication rates, especially if the patient had a previous history of periodontitis.

The recommended protocol for supportive therapy for patients who have been treated for peri-implant disease consists of four steps: 1. Examination, re-evaluation and diagnosis 2. Motivation, re-instruction and instrumentation 3. Treatment of re-infected sites 4. Risk assessment Having completed these steps the recall interval should be determined. The periodontal risk assessment is a useful tool for establishing the recall frequency and is available for download from the University of Bern website www.perio-tools.com.

How successful is supportive therapy in prevention of peri-implant disease Mariano Sanz This presentation looked at prevention of periimplantitis at three levels, and asked if each of these was possible: 1. Prevention of mucositis and maintenance of periimplant health (primary prevention) 2. Control of mucositis to prevent the onset of periimplantitis (secondary prevention) 3. Early detection and successful treatment of periimplantitis to achieve long-term maintenance of implants (tertiary prevention)

maintain good implant health (expressed in terms of stable bone levels) by performing supportive therapy two or three times per year. In a second study3, maxillary implants placed immediately following extraction showed neither inflammatory nor marginal bone level impairment three years after restoration. It should be noted that a clustering of failures was observed in a few patients, and in all cases a high level of discipline and compliance was required from the patients. The evidence presented suggested that scenario 1 is possible, and this seems to be the main condition for a successful prevention.

Scenario 1 At present there are no studies on primary prevention. However, a five year prospective observational study on patients susceptible to periodontitis2, stated that it should be possible to

Scenario 2 Mucositis is defined as the presence of inflammatory signs without bone loss. Assessment using standardised probing is the clinical measure that is

2 WennstrĂśm et al. JCP 2004

3 Sanz et al. COIR 2014

Figure 9.3.1

Figure 9.3.2

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used to distinguish between peri-implant health and disease. Bleeding on probing is considered to be a predictor for mucositis, although there is no reliable indicator of further progression of bone loss leading to peri-implantitis4 (Figure 9.3.1). Once mucositis has been established, managing it to prevent the development of peri-implantitis is of key importance (Figure 9.3.2). Current data from RCTs indicates that the resolution of inflammation is possible, although it is not achieved in all patients5. Up until now, patient-administered mechanical plaque control has been the primary measure used to prevent the progression of the disease. However, inadequate plaque control often results from prostheses that are hard or impossible to clean properly (Figure 9.3.3).

As a result, appropriate implant placement and prosthesis design are of key importance.

Scenario 3 To illustrate the third question, the speaker presented a clinical case following all stages from diagnosis, to non-surgical treatment, re-evaluation and surgery, showing a drastic improvement of the clinical situation after regenerative surgery.

Figure 9.3.3

Conclusion Early detection of peri-implant disease involves establishing a baseline, then assessing the patient at maintenance visits using peri-implant probing.

This will identify the onset of inflammation and its further progression (Figure 9.3.4).

4 Dierens et al COIR 2012 5 Jepsen et al. JCP 2015 Figure 9.3.4

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Imaging (radiology) in treatment planning and follow-up Presurgical imaging in implant treatment: from guidelines to clinical use Michael Bornstein The use of ionizing radiation must always be justified and optimised. Nevertheless, proper guidelines for the use of CBCT in implant dentistry, based on sound scientific research, are still lacking.

2D radiology has been used extensively for many years. The advent of 3D radiology has provided superior tools for diagnosis and treatment planning.

Its use can be justified for assessing the morphology and dimensions of the ridge and the anatomical boundaries, as well as for determining bone orientation, but it must always be used according to the ALARA principle of radiation exposure (As Low As Reasonably Achievable).

CBCT should only be used when the question for which imaging is required cannot be answered adequately by lower dose conventional (traditional) radiography In 2012, the EAO published its recommendations on the clinical indications for CBCT: extensive bone augmentation; sinus floor elevation; evaluation of intra-oral donor sites; special surgical techniques; computer treatment guided; post-operative complications The ITI Consensus in 2014 stated:

There are three recently published sets of guidelines1: In 2008 the European Academy of Dentomaxillofacial Radiology (EADMFR) published its statement on the use of CBCT. This stated: CBCT examinations must be justified for each patient to demonstrate that the benefits outweigh the risks CBCT examinations should potentially add new information to aid the patient’s management

1 Horner et al. Dentomaxillofac Radiol 2009; Harris et al.

COIR 2012; Bornstein et al. IJOMI 2014

significant dose reduction can be achieved by using CBCT instead of CT, by adjusting exposure parameters and reducing the FOV (Field Of View) that should be restricted to the ROI (Region Of Interest) How often is CBCT used in dentistry?

Use of CBCT peaks in two age groups: those aged around 20 who have experienced dentoalveolar injury; and those aged around 55 who are being treated for partial edentulism2

2 Bornstein et al IJOMI 2015

CBCT imaging for implant treatment planning in the anterior maxilla

CBCT imaging for implant treatment planning in the posterior maxilla

Relevant clinical questions

Relevant clinical questions

• Is correct 3-dimensional (3D) implant positioning possible?

• Is correct 3-dimensional (3D) implant positioning possible?

• Can we achieve good primary stability in the desired position?

• Can we achieve good primary stability?

• If primary stability is not achievable: decide between site develoment using guided bone regeneration (GBR) procedures or an alternative treatment concept not using dental implants.

• When GBR is needed, can we use a simultaneous approach with implant insertion or do we need a staged procedure?

• When GBR is not indicated, can we place the implant using a flapless approach?

Figure 10.1.1

Anatomic structures of interest • Nasal floor • Nasopalatine canal • Anterior superior alveolar canal and canalis sinuosus

• If primary stability is not achievable: site develoment using sinus floor elevation (SFE) procedures or an alternative treatment concept not using dental implants.

• When SFE is needed, can we use a simultaneous approach with implant insertion or do we need a staged procedure?

• When a simultaneous SFE is possible, do we use a lateral window or a transcrestal osteotome technique?

Healthy maxillary sinus

Maxillary sinusitis of odontogenic origin

Figure 10.1.2

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What is CBCT used for? (Figures 10.1.1–10.1.4)

CBCT imaging for implant treatment planning in the anterior mandible

CBCT imaging for implant treatment planning in the posterior mandible

Relevant clinical questions

Relevant clinical questions

• Is correct 3-dimensional (3D) implant positioning possible?

• Is correct 3-dimensional (3D) implant positioning possible?

• Can we achieve good primary stability in the desired position?

• Can we achieve good primary stability in the desired position?

• If primary stability is not achievable: decide between site develoment using guided bone regeneration (GBR) procedures or an alternative treatment concept not using dental implants.

• If primary stability is not achievable: decide between site develoment using guided bone regeneration (GBR) procedures or an alternative treatment concept not using dental implants.

• When GBR is needed, can we use a simultaneous approach with implant insertion or do we need a staged procedure?

• When GBR is not indicated, can we place the implant using a flapless approach?

Anatomic structures of interest

Anatomic structures of interest •Mandibular canal (+)

• When GBR is needed, can we use a simultaneous approach with implant insertion or do we need a staged procedure?

• Lingual foramen (*) • Incisive canal • Genial tubercles von Arx T, Matter D, Buser D, Bornstein MM: Evaluation of location and dimensions of lingual foramina using limited cone-beam computed tomography. J Oral Maxillofac Surg 2011;69:2777-85.

Figure 10.1.3

• When GBR is not indicated, can we place the implant using a flapless approach?

•Mental foramina (*) •Sublingual fossa / “lingual undercut“ •Retromolar canal von Arx T, Friedli M, Sendi P, Lozanoff S, Bornstein MM: Location and dimensions of the mental foramen: a radiographic analysis using cone-beam computed tomography. J Endod, 39: 1522-1528, 2013

Figure 10.1.4

Do we still need to use Hounsfield scores in presurgical planning?

Reinhilde Jacobs Changing concepts regarding bone quality assessment Historically, presurgical planning of implant placement focused on good bone density as a quality measure of the host bed. Yet as time went by, implant surfaces were roughened which altered the requirements of potential bony implant sites. Presurgically, one should now focus on the vascularisation of the bone bed, which can be indirectly qualified by a structural bone analysis.

It can be assumed that a moderately dense, homogeneously trabecularised bone, represents a healthy vascularisation during the initial remodelling around the placed implant.

Meanwhile, as the bone quality requirement for implant sites changed, CBCT was introduced for presurgical planning. The latter confronted clinicians with information presented in other data formats, as well as introducing new variables. Apparently,

standardised bone density measures, known as Hounsfield scores for multislice CT imaging, could no longer be used in CBCT devices (Pauwels et al 2014). Nonetheless, as stated above, implants may no longer need such bone density measures. Instead, structural analysis of the trabecular bone matrix via bone morphometric software may offer some solution (Huang et al 2014; Van Dessel et al 2014; Huang et al 2015) (Figure 10.2.1). Unfortunately, the shortcoming remains the lack of visualisation of the initial non-mineralised bone matrix via hard tissue imaging modalities such as CBCT (Van Dessel et al 2015) (Figure 10.2.2).

References Van Dessel et al. DMFR 2014; Huang et al Bone Res 2014; Pauwels et al DMFR 2014; Van Dessel et al EAO Stockholm 2015 poster #613; Huang et al EAO Stockholm 2015 poster #548

Figure 10.2.1. Example of structural analysis of human trabecular and cortical bone with MicroCT and CBCT (Huang et al 2015)

Figure 10.2.2. Structural bone analysis of traditional socket healing after tooth extraction.

The red part represents the mineralised bone after 3 months of healing, with the yellow part indicating the remaining non-mineralised inner part of the socket (Van Dessel et al 2015)

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Radiographic bone quality aspects in planning implant surgery Christina Lindh There is overwhelming evidence to show that bone quality is a key factor in the success or failure of implant dentistry. Since the early 1990s the density of bone at the surgical site has been considered a significant factor in the prognosis and likely success of implants.

How to define bone quality There are many different classification systems for defining bone quality, and significant heterogeneity is revealed when the results of different studies are compared. At present there is no consensus on either what bone quality means or how to assess the quality of bone3 (Figure 10.3.1). The most widely used classification (Lekholm & Zarb 1985) is based on radiograph evidence and tactile perception achieved during drilling, and derives from a purely structural approach.

There is now a growing understanding that type IV may not be the worst bone quality. Current thinking on bone quality takes into account both bone mineral density (BMD) and the three-dimensional microstructure of the bone.

3 Ribeiro-Rotta Clin Oral Impl Res 2011; Lindh et al. Clin Oral Impl Res 2014

How to measure bone quality Bone structure has a hierarchical pattern and a trabecular arrangement, which can vary between being closely packed or sparse.(Figure 10.3.2). Crosssectional CBCT imaging can reveal a visual grading in the bone structure, but in a rather subjective way.

Inter-observer variability is a problem. Some semiautomated systems for evaluating bone quality are in the process of being developed, but for the moment radiographic density should be used with caution, as ability to evaluate the image depends on factors such as brightness and contrast variation. The current standard measure of bone quality is bone mineral density (BMD), calculated in Hounsfield units derived from the CT scan. A significant correlation has been observed between BMD, RFA (ISQ values), anti-rotational stability and L-Z classification4.

Conclusion Computed tomography and tactile perception are currently the most predictable methods of evaluating bone quality before implant placement. Various enhanced evaluation methods are being developed, and at present no technique is available to precisely determine bone quality as single factor (Figures 10.3.3 and 10.3.4).

4 Bergkvist et al. IJOMI 2010

What is bone quality??

Bone quality in the field of osteoporosis and fracture prediction

Good

Bad

Radiographic bone quality aspects in the implant field

Five anatomical levels of bone organization Adapted from Chappard D et al., 2011; Donelly E 2011.

Figure 10.3.1

Figure 10.3.2

Semia-automated calculations of trabecular structure

CONCLUSIONS

• Density and structure of jaw bone tissue vary between and within the jaws - site specific assesment can be recommended before implant installation • The Lekholm&Zarb classification based of radiographs and tactile perception is a valid method to assess jaw bone before implant installation • Intraoral and panoramic radiographs can be used to assess trabecular structure of jaw bone tissue

Region of interest (ROI)

Figure 10.3.3

• Newer radiographic technologies might be useful - has to be prooven!

Figure 10.3.4

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Creating the virtual patient: how to integrate facial, optical and radiological imaging components Ali Tahmaseb New technologies are now permitting the creation of a ‘virtual patient’ that integrates data from bone, teeth, oral soft tissue and the facial surface.

Superimposing software can merge 3D bone anatomy, intraoral scanned data and extraoral facial information obtained from a surface scanner (Figure 10.4.1).

Some limitations in the 3D skeletal data acquisition come from artefacts, patient movement and the registration of data in the open and closed mouth.

The superimpositions require reference points and a strict protocol of data acquisition. This can be challenging in a fully edentulous patient because of the instability of templates (Figure 10.4.2).

Once the ‘virtual patient’ has been built, it is possible to create a virtual set-up and develop fully milled provisional prostheses (Figures 10.4.3 and 10.4.4). It is anticipated that this will become an increasingly common way of working in the future.

© ALI TAHMASEB 2016 Figure 10.4.1

© ALI TAHMASEB 2016 Figure 10.4.2

© ALI TAHMASEB 2016 Figure 10.4.3

© ALI TAHMASEB 2016 Figure 10.4.4

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Peri-implantitis Peri-implantitis is one of the major challenges in implant dentistry. There is a lack of deep understanding about its pathogenic process, and while numerous treatment protocols have been proposed, there is no adequate solution to it in many cases. As such, it is a key topic for discussion at an implant meeting.

During this session: Andrea Mombelli explored the possibility of using different materials in order to achieve a better resistance to biofilms Stefan Revert looked at current treatment protocols and their outcomes, with suggestions for daily practice Olivier Carcuac presented a comprehensive review of the factors involved in different treatment outcomes Tord Berglundh described the experimental research being carried out at his department which is shedding light on the histopathologic nature of the disease

The relevance of implant materials for peri-implantitis Andrea Mombelli Zirconia has become established as an alternative material to titanium for dental implants due to its aesthetic properties, high biocompatibility and a potentially lower susceptibility to bacterial adhesion.

Recently, a new two-piece zirconia implant (ZERAMEX® T Implant System), with an etched zirconia surface, has been introduced. The speaker presented the first prospective clinical study to use this system1. Data are available currently from a mean observation time of 3.5 years after loading.

The survival rate one year after loading was 87%.

The failures were all the result of aseptic loosening.

Interestingly, no further complications of this kind were noted thereafter and no peri-implantitis was seen, strongly suggesting a different pattern of failure than in the case of titanium implants.

1 Cionca et al. Clin Oral Impl Res 2015

Next, he focused on biofilm adhesion on implant surfaces. A lower mean total bacterial count was observed on zirconia, compared with titanium2. In addition, an immunohistochemical study comparing tissues adjacent to healing caps made of zirconium or titanium demonstrated greater expression of several pro-inflammatory markers around titanium caps3.

Despite the lack of long-term clinical observation, no peri-implantitis has been reported on zirconia implants, and their cumulative survival rates are high. As a result they may represent a promising new technology.

2 Nascimento et al. Clin Oral Impl Res 2014 3 Degidi et al. J Periodontol 2006

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The patient and the problem awaits Monday morning� What do I do?

Stefan Renvert peri-implant pathology at two-year follow-up4.

Based on this, we have to consider that the clinical success of surgery for peri-implantitis is low.

Answering the question posed in the title After an appropriate diagnosis of the patient’s condition, the first step in treating peri-implantitis should always be non-surgical, based around reinforcing plaque control and improving the oral periodontal condition. This is also an appropriate stage at which to assess the patient’s compliance more carefully.

Do certain techniques provide better results than others when treating peri-implantitis?

One RCT found better resolution of defects when carrying out augmentation using porous titanium granules versus open flap debridement alone5. In another RCT, peri-implantitis patients were treated with Algipor®, with or without membrane, and there were no significant differences in the outcome6.

The speaker presented a chart in which the morphology of the defect was the key factor used to select the surgical technique (Figure 11.2.2). He also made some recommendations about treatment for peri-implantitis (Figure 11.2.3).

If the infection has not been controlled when the patient is re-evaluated, the case should be considered to be advanced. In these circumstances, surgery is necessary to provide better accessibility to the affected area and to achieve pocket reduction (Figure 11.2.1).

What about the outcomes of surgery for peri-implantitis?

Having undergone surgical resective treatment, 42% of patients do not heal completely and have

4 Serino & Turri. Clin Oral Impl Res 2011 5 Jepsen et al. J Dent Res 2015 6 Roos-Jansaker et al. J Clin Periodontol 2014

6›

TREATMENTS

Diagnosis of peri-implantitis

Nonsurgical therapy

Infection controlled

Removal of implant

Re-evaluation

Infection not controlled

Adequate

Soft tissue conditions

Not adequate

Figure 11.2.1 Gingival grafting

Infection not controlled

Re-evaluation

Based on limited available evidence (and long time clinical practice I would suggest)

Infection controlled

•

Always start with non-surgical therapy- it may work

•

In case of no healing surgery may be needed

Regenerative therapy

M a i n t e n a n c e

Fig 6-39 Decision tree for the selection of treatment based on the condition of the soft tissue around the peri-implantitis–affected implant, and the therapeutic process in managing the soft tissue if deemed necessary before regenerative therapy.

167

Figure 11.2.2

•

Expose implant surface

•

Remove granulation tissue

•

Mechanically clean the implant surface

•

Chemically remove remaining debris and smear-layer (H2O2 3%)

•

In 3 and 4-wall defects consider regenerative therapy

Figure 11.2.3

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Challenges in the treatment of peri-implantitis Olivier Carcuac Goals of treatment for peri-implantitis As peri-implantitis is caused by bacteria, treatment of the disease should include anti-infective measures and the goals of the therapy should include disease resolution and preservation of supporting bone. A consensus report from the 8th European Workshop on Periodontology stated that treatment success should be described as a composite outcome including a combination of findings from clinical and radiological assessments7. Such assessments include pocket closure, resolution of peri-implant inflammation and no further loss of supporting bone.

use of adjunctive systemic antibiotics. The potential benefit of antibiotics, however, was not known.

In a prospective randomised controlled clinical trial on 100 patients, the effect of adjunctive systemic antibiotics on surgical treatment of peri-implantitis was evaluated10. Treatment success was defined using a composite outcome, including PPD ≤ 5mm, absence of bleeding/suppuration and no further bone loss at the 12-month examination after surgical therapy.

It was demonstrated that:

Non-surgical therapy Non-surgical therapy alone does not seem to be effective in the resolution of moderate/ severe forms of peri-implantitis. However, non-surgical procedures should always precede surgical therapy in all peri-implantitis cases in order to establish appropriate soft tissue conditions and optimal selfperformed infection control.

Surgical therapy Surgical therapy is required in the treatment of peri-implantitis to provide access for debridement of contaminated implant surfaces. The use of different decontamination procedures has included mechanical and chemical techniques, but no single method or combination of methods has been shown to be superior.

Results from pre-clinical in vivo studies on surgical treatment of experimental peri-implantitis demonstrated (i) that resolution of the disease is possible in the absence of adjunctive use of local antimicrobial therapy8, 9, and (ii) that implant surface characteristics do influence treatment outcome8, 9.

treatment success was detected in 45% of the implants/38% of the patients the local use of chlorhexidine had no overall effect on treatment outcome implant surface characteristics influenced the outcome of surgical treatment of peri-implantitis a positive effect on treatment success was observed at implants with modified surfaces, while adjunctive systemic antibiotics had no impact on treatment success at implants with non-modified surface the likelihood for treatment success using adjunctive systemic antibiotics in patients with implants with modified surfaces, however was low Risk for recurrence While publications have presented favourable shortterm results, several studies also reported findings on lack of disease resolution, recurrence of disease and implant loss. Studies reporting long-term data of 5 years and longer from well-designed prospective controlled clinical trials, and using composite outcomes of treatment success, are therefore needed.

Previous studies describing outcomes of surgical therapy of peri-implantitis have often included the 7 Sanz & Chapple J Clin Periodontol 2012 8 Albouy et al J Clin Periodontol 2011 9 Carcuac et al J Clin Periodontol 2015

10 Carcuac et al J Dent Res 2016

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A comparison between periodontitis and peri-implantitis lesions Tord Berglundh Periodontitis and peri-implantitis11 represent a global problem and it is essential that we advance our understanding of their onset and progression.

Various studies of ‘experimental peri-implantitis’ that mimic the real process have been conducted in

animal models. Based on these animal studies, and corroborated by analyses of human biopsies, the histopathological differences between periodontitis and peri-implantitis lesions have been thoroughly described. In periodontitis a ‘self-limiting’ process occurs due the presence of an attachment of periodontal fibres into the teeth, leading to a connective encapsulation that separates the inflammatory cell infiltrate from the bone. In periimplantitis, however, tissue destruction is more pronounced as the lesion is not surrounded by noninfiltrated connective tissue. The inflammatory cell infiltrate reaches a more apical location, with a huge number of polymorphonuclear neutrophils (PMNs) and macrophages13, 14.

11 Kassebaun et al J Dent Res 2014, Derks et al. J Dent Res 2015 12 Lang et al. J Clin Periodontol 2011

13 Berglundh et al. J Clin Periodontol 2011 14 Carcuac & Berglundh, J Dent Res 2014

There is a continuum from healthy mucosa to mucositis and from mucositis to peri-implantitis.

The host response to oral biofilms does not differ whether they are present around a tooth or an implant, and in both cases an inflammatory lesion develops12. Peri-implant mucositis represents the obvious precursor to peri-implantitis as does gingivitis to periodontitis.

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Emerging surgical concepts A variety of new materials are currently being introduced into general practice to facilitate regeneration in an attempt to simplify treatment and lower patient morbidity. In the case of these new materials, it is important to distinguish between commercial claims and what has been scientifically proven. This session looked at growth factors; soft tissue substitutes; provided an update on biomaterials for hard tissue grafts; and explored a new development in the field of leucocyte-platelet rich fibrine: L-PRF.

Do we still need autogenous bone for ridge augmentation or can we use growth factors?

Ronald Jung Autogenous bone continues to be considered the ‘gold standard’ in bone regeneration, but due to associated patient morbidity, research is currently focused on growth factors. Originally an area of animal research, within the last seven years new clinical studies have been undertaken in humans, particularly using recombinant human bone morphogenetic protein-2 (rhBMP-2). These have been limited because the carrier used – absorbable collagen sponge (ACS) – lacks the consistency needed for lateral augmentation. Two alternatives have been proposed to overcome this problem: using a titanium mesh to provide space and stabilise the wound, and mixing rhBMP-2 with a consistent graft material as a carrier.

In an RCT involving 11 patients with 34 implants, where bone fill-in test and control sites were clinically similar, histomorphometric analysis revealed more lamellar bone in the sites that received rhBMP-2, along with an increased contact to the graft. The authors concluded that rhBMP-2 enhances the maturation process of bone, and consequently has the potential to improve and P-2

rhBM

accelerate guided bone regeneration1. The longterm results revealed no significant differences, demonstrating the safety of rhBMP-2, the stability of the results and the absence of complications2.

In another RCT by the same group, which included CBCT measurements and histologic analysis, rhBMP-2 was tested together with xenogeneic bone blocks in comparison with autogenous bone blocks as a control group 3. The clinical assessment was similar in the test and control sites, but the patient morbidity made the big difference.

So, why don’t we use rhBMP-2 more frequently?

Because it is for now an emerging and expensive technology – although in the words of the speaker one that has already has very exciting potential.

1 Jung et al. Clin Oral Impl Res 2003 2 Jung et al. Clin Oral Impl Res 2009 3 Thoma et al. manuscript in preparation

The effect of rhBMP-2 on guided bone regeneration in humans Jung RE, Glauser R, Schärer P, Hämmerle CHF, Weber FE

P-2

rhBM

Clin Oral Impl Res 2003

Histomorphometric results

BM

DB

DBBM

„When I see these results, why do we not use rhBMP-2 more in clinical practice?“

• Stat. significant more lamellar bone at the test sites • Stat. significant more bone to graft contact at the test sites

control

test preoperative

Figure 12.1.1

6 mo post

Figure 12.1.2

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Results

P-2

rhBM

Results

P-2

rhBM

preop

4 mo

Patient morbidity

preop

12 patients

days of medicatioin/swelling

Horizontal ridge width im mm

clinical assessment

4 mo

* no statistical difference

12 patients

autogenous bone

* no statistical difference

Figure 12.1.3

rhBMP-2

Figure 12.1.4

Do we still need autogenous bone for ridge augmentation?

Mike

„How hard do we have to work to get a good result result?“ ?“

„How hard do we have to work to get a good result?“

?

?

Figure 12.1.5

Figure 12.1.6

Overall Conclusions rhBMP-2 reveal the highest potential for bone regeneration.

BMP-2 shows the best documentation, however, it is only approved for extraction sockets and for sinus floor elevations. It is expensive and need high clinical doses. rhBMP-2 combined with a mechanically stable xenogenic bone block revealed similar results as an autogenous bone block With an increased body of literature it might be possible to expand the indication spectrum of rhBMP-2 in order to replace Carrier/ bone autogenous bone blocks matrix regeneration Cells/tissues We should stay excited for the sake of our patients with challenging defects

Figure 12.1.7

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Soft tissue grafts out of the box. What can we expect in clinics?

Otto Zuhr Although written evidence lacks relevant data for the most part, among available augmentation materials, autogenous subepithelial connective tissue grafts (SCTGs) are still considered as the ‘gold standard’ to increase the width of keratinised tissue and for soft tissue volume augmentation to date4. However, there is a restrictive core of critical elements that can be summarised as follows: 1. The term ‘gold standard’ implies a well-defined and consistent standard of harvesting procedure.

However, different donor sites that can be selected from the palate and varying harvesting techniques that can be applied result in different kinds of SCTGs that vary in their histological composition, obviously leading to different characteristics that might require selective clinical application 2. At present, the clinical decision as to where to harvest SCTGs from is hardly based on scientific evidence, but rather depends on the amount of available tissue at the eligible donor sites; the indication in which the transplant is supposed to be used; and in particular on the personal preference of the treating surgeon 3. Independent of the selected donor site, the clinical procedure of SCTG harvesting from the palate is basically characterised by the challenge of obtaining an adequate amount of tissue while

minimising postoperative pain and reducing the risk of complications at its best 4. The limited amount of grafting tissue and the increased patient morbidity are substantial disadvantages of autogenous SCTGs. For this reason the search for suitable soft tissue substitutes is currently at the centre of numerous efforts by scientists and manufacturers, and will be an important field of future research – for the good of the patient!

5. Many questions with regard to graft healing and volumetric stability remain presently unknown – this relates both to soft tissue substitutes, and also to autogenous SCTGs. Patient-centred outcome measures, quantitative three-dimensional and qualitative-aesthetic assessment of treatment results, as well as long-term follow up data, are scarcely available at present 6. Thus, more research is needed to further progress and increase knowledge regarding soft tissue volume augmentation procedures in plastic periodontal and implant surgery. Ultimately, the goal cannot be considerably different from developing appropriate soft tissue substitutes for all conceivable indications and by doing so rendering soft tissue autografts unnecessary, and eliminating their clinical application to the greatest possible extent

4 Zuhr et al. J Clin Periodontol 2014;41:123–142

Sonntag, 20. Dezember 15

Sonntag, 20. Dezember 15

Sonntag, 20. Dezember 15

Sonntag, 20. Dezember 15

Figure 12.2.1

Figure 12.2.3

Figure 12.2.2

Figure 12.2.4

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Emerging concepts in maxillofacial surgery: indications for graft materials Henning Schliephake The concept of the ‘skeletal envelope’ is one of the fundamental principles that underlies bone regeneration. Wound healing is a process that is dependent on both the characteristics of the graft material and the morphology of the defect. To achieve the best result, the material must have osseoconductivity (a quality that is closely related to its porous structure) and the defect should be auto-containing. Regeneration will be quite different within or outside the biological limits of the skeletal envelope (Figure 12.3.1).

The speaker went on to discuss a systematic review, still in preparation, on the efficacy of grafting materials in ridge augmentation. Having selected 184 studies, involving 6,373 augmentations, he drew the following conclusions: allowing for the standard deviations of the mean values, the different types of graft materials did not appear to have a significant effect on the

Indications for graft materials Basic considerations

percentage of bone filling, implant survival or complication rates taking into account the defect morphology, in dehiscence defects (within the skeletal envelope), particulate graft materials provide an 80% defect filling, slightly less than synthetic materials in lateral/vertical defects, outside the skeletal envelope, particulate graft material can be expected to gain about 3.5mm in width and height with acceptable stability block shaped grafts can increase this gain by 1mm, but are unlikely to produce greater height, with the exception of extraoral autogenous bone (Figures 12.3.2 and 12.3.3) These conclusions may change in the near future when the biological quality of graft materials is enhanced.

To this end, there are two emerging technologies that are relevant: growth factors and stem cells.

At present, evidence for the efficacy of these is limited to early clinical observations based on case series without controls. The use of concentrate bone marrow aspirates in sinus grafting has been evaluated in a chairside technique, without demonstrating significant differences. The use of in vitro cultivated stem cells requires Good Manufacturing Practices and Good Laboratory Practice (GMP/GLP) environments, and is for the moment beyond the scope of daily practice (Figures 12.3.4 and 12.3.5).

Outside the „Skeletal Envelope“

Within the „Skeletal Envelope“

Figure 12.3.1

Indications for graft materials

Indications for graft materials

Clinical evidence

Clinical evidence

Systematic Review / Defect Characteristics / Outside the Skeletal Envelope

Systematic Review / Defect Characteristics / Outside the Skeletal Envelope Block shaped Graft Material / Ridge Dimensions Horizontal gain

14,0

p=0.001

Vertical gain

mm Change in Dimension

12,0 10,0 8,0

8,8

6,0 4,0

4,6

2,0

3,7

4,5 3,3

4,4

3,5

2,3

0,0

Allogenic

Xenogenic

Autogenous e.o.

Autogenous i.o.

Tröltzsch et al. Efficacy of grafting materials in ridge augmentation – a systematic review (in preparation)

Figure 12.3.2

Figure 12.3.3

Indications for graft materials

Indications for graft materials

Emerging concepts?

Emerging concepts?

Enhanced biological quality / Stem cells

Enhanced biological quality

In vitro expansion CaPO4 CD 105

PLA

CD 45

CD 90

CD 34

CD 73

CD 14

Domicini et al. 2006

CaCO3

Figure 12.3.4

• Growth Factors

Min. Coll.

• Stem Cells

Figure 12.3.5

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The future of wound healing: can it still be improved?

Nelson Pinto L-PRF (leukocyte-platelet rich fibrin) is one of the four main families of platelet concentrates5. It is applied as a membrane to protect the wound and to stimulate cell proliferation in the healing process by the local release of numerous growth factors.

It works in a more prolonged way than platelet concentrates without leucocytes. However, at the moment there is a lack of controlled studies to compare the effects of different types of platelet-rich plasma.

The speaker presented various challenging clinical cases where he has used L-PRF with good results, especially in alveolar ridge preservation (Figure 12.4.1). He claimed that besides its regenerative effect, L-PRF also has antibacterial properties.

Following his early experience of using L-PRF to treat wounds in horses, he has successfully applied the technique in chronic human wounds. He illustrated many impressive cases relating to the diabetic foot and venous ulcers.

The potential osseoinductive effect on the recruitment and differentiation of bone precursor cells has been explored using the so-called â&#x20AC;&#x2DC;floating implantâ&#x20AC;&#x2122; study. Implants with different surfaces were placed in oversized osteotomies in presence of L-PRF with no primary stability. Early results have been promising.

Figure 12.4.1

5 Ehrenfest et al. Muscles Ligaments and Tendons J. 2014

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