Geistlich News 02-18 English

GEISTLICH BIOMATERIALS

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VOLUME 13, ISSUE 2, 2018

FOCUS PAGE 5

JOURNAL CLUB PAGE 28

OUTSIDE THE BOX PAGE 32

Anterior region in the spotlight.

Stem cells in dentistry.

The regeneration hero in distress.

How to regenerate lost tissues in the most visible part of the mouth. Is it just a matter of appearance?

Can they help regenerate bone, ligament, papilla and pulp? The expert's opinion.

Less than 1200 axolotls in the wild.

Will we discover the secret of their regenerative capacity in time?

LEADING REGENERATION.

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CONTENTS

Issue 2 | 2018 EDITORIAL

4 We care about your success.

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Anterior area and aesthetics.

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New collagen matrix facilitates recession coverage Dr. Martina Stefanini and Prof. Giovanni Zucchelli | Italy

9 A new and more accurate measure of soft tissue changes Adjunct Prof. Dr. Tiago Morelli | USA

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How to deal with missing anterior teeth. Take stock of the situation Prof. Lin Ye and Dr. Jiang Xi | China

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The biology behind Geistlich Bio-Oss® Associate Prof. Dieter D. Bosshardt | Switzerland

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Use of Yxoss CBR® in the anterior area Prof. Frank Liebaug | China & Germany

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Sequential extractions and implantations Dr. Philippe Khayat and Dr. Marin Pomperski | France

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Facing dehiscence defects in the anterior area Dr. Shakeel Shahdad | UK JOURNAL CLUB

28 Milestone studies.

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An overview about stem cells in regenerative dentistry Prof. André Antonio Pelegrine and Dr. Antonio Carlos Aloise | Brazil OUTSIDE THE BOX

32 The Pallid Marvel of Regeneration.

GEISTLICH PHARMA AG | OSTEOLOGY FOUNDATION

34 Background.

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A “Treatment Concepts” portfolio exactly like no other

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Complex bone augmentation? The future is now!

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Winners of the Gappy Game

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News from the Osteology Foundation INTERVIEW

38 In the phantom room with Anton Sculean.

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Publishing information

3

Editorial

We care about your success.

Exactly like no other.

“Genevieve, Josiah, Henry, Amy and Mark...”

Photo: Roger Schuler

These are five of the passengers on a flight that landed in Zürich 20 July, 2016. Our family of five arrived in Switzerland, and we began our new life here. I started my career at Geistlich, and now, two years later, I would like to share some of my thoughts on Geistlich – Exactly Like No Other.

Change Signature

This issue of Geistlich News is focused on the anterior area and aesthetics. Meeting the aesthetic outcome requirements of our dental customers is a critical aspect of our success, and being able to understand the connection between our customer, the products and the patient is an absolute necessity. Most pharmaceutical therapies are self-administered by the patient (e.g., taking a pill, applying a medicinal pad, etc.). But almost all medical devices are delivered by a clinician. Geistlich Bio-Oss® and Geistlich Bio-Gide®, for example, are carefully placed into the patient using special, surgical instruments operated by highly skilled hands. Thus the handling of a device often becomes one of its most important characteristics, and handling can be just as important as biological performance. Geistlich Bio-Oss® Collagen and Geistlich Bio-Oss® Pen were designed specifically with the customer in mind. While Geistlich products are recognized as being best-in-class, in order to maintain this distinction, our new technologies must be developed with a thorough understanding of how they will be handled and delivered.

My family and I have enjoyed our time in Switzerland, and I enjoy being a part of the Geistlich “family.” I look forward to helping Geistlich strengthen our link to our customers' needs, and I look forward to future innovation, especially at the interface where product meets customer.

This one is from Zingg Falk in attachment

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Dr. Mark Spilker Chief Scientific Officer

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ANTERIOR AREA AND AESTHETICS.

Photo: iStock / YanLev

How to regenerate large bone deficiencies, treat soft tissue recessions and place implants in the most visible part of the mouth.

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Soft tissue management in the anterior area

New collagen matrix facilitates recession coverage Prof. Giovanni Zucchelli, Italy Department of Periodontology University of Bologna

Dr. Martina Stefanini, Italy Department of Periodontology University of Bologna

Eliminating the need for graft harvest and integrating well with surrounding soft tissue, the volume stable collagen matrix Geistlich Fibro-Gide® is an effective biomaterial for treating recession defects.

For many patients, anterior tooth aesthetics means not only beautiful teeth but also well-formed gingiva. Often, only the most coronal recession is visible when smiling, and it is this “millimeter” to which the patient's attention is drawn. If root coverage is not complete, patients may see the result as a failure. Therefore, root coverage up to the cement-enamel-junction is the goal when patients complain about the aesthetic appearance of their teeth and gums.

It is also important that the result be stable long-term, reducing the risk of recession recurrence.

flap is necessary. Nonetheless, harvesting a connective tissue graft from the palate is not well accepted by patients. It increases chair time and is associated with patient discomfort, swelling and sometimes pain at the palatal donor site. For the surgeon, graft harvest is demanding, time-consuming and supply may be limited.

That’s why alternatives are desireable. The newly developed xenogeneic collagen matrix Geistlich Fibro-Gide® has been tested for over ten-years in numerous in vitro, preclinical and clinical models and has demonstrated favorable mechanical and biological properties.

Geistlich Fibro-Gide® stabilizes the blood clot so that, over time, it becomes new connective tissue that will increase soft tissue thickness in the treated area.

The safety and preliminary efficacy of the volume-stable matrix in the treatment of isolated gingival recessions has been evaluated in a pilot c­linical study, which has led to a proposed draft for a step-bystep clinical protocol.

Coronally advanced flap plus graft or matrix

Flap design: split-full-split thickness

Creating a coronally advanced flap (CAF) is a very predictable technique for obtaining complete root coverage along with a pleasant aesthetic result. However, if there is insufficient keratinized tissue apical to the recession defect or if there is a need to increase soft tissue thickness, the adjunctive use of a connective tissue graft under the

The flap design of choice for treating single gingival recessions is trapezoidal. It is defined by two, 3 mm horizontal incisions and two slightly divergent vertical releasing incisions, as short as possible and not extending into the alveolar mucosa. Flap elevation should be done with a “splitfull-split” approach in the coronal-apical

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direction. The papillae between the horizontal incisions and the probeable sulcular area apical to the root exposure are ­elevated split thickness, keeping the blade almost parallel to the bone. Then a periosteal elevator should be inserted into the probeable sulcus to extend the flap into a full thickness flap in the apical direction, exposing up to 3–4 mm of bone apical to the bone dehiscence. The rationale for the elevation of the full thickness flap is to include the periosteum in the central portion of the flap that, once the flap is advanced, will cover the avascular root surface, so that the blood supply is guaranteed in this sensitive area. (Fig. 1) Apical to the bone exposure flap, elevation continues to split thickness and finishes as soon as it is possible to move the flap passively in the coronal direction.

To permit the coronal advancement of the flap, muscle insertions should be detached first from the periosteum and then from the alveolar mucosa of the flap. This is done first by keeping the blade parallel to the bone and then parallel to the external mucosal surface. Coronal mobilization of the flap is considered ‘‘adequate’’ when the marginal portion of the flap can passively reach a level coronal to the cemento-enamel junction (CEJ). The passivity of the flap is one of the key aspects of the procedure. The root surface is mechanically treated with curettes, and EDTA 24% gel is r­ ecommended for removing the smear layer from dentinal tubules. The facial soft

tissue of the anatomic papillae coronal to the horizontal incisions should be de-epithelized to create connective tissue beds, to which the surgical papillae of the coronally advanced flap can be sutured.

Cutting and positioning the matrix The matrix should be trimmed and shaped using a new blade in the dry state. The dimension of the matrix should be 6 mm wider than the recession width measured at the CEJ level, and the height should go beyond the buccal bone dehiscence, with about 2-3 mm of the matrix lying above the bone. Since the matrix can be used in different indications requiring different thickness, the manufac-

turer provides it with a standard thickness of 6 mm. For treating gingival recessions around teeth, the thickness should be reduced by cutting the matrix to a thickness of about 3–4 mm in the central portion. The matrix can be further thinned at the margins to facilitate suturing.

The matrix should be applied in a dry state and placed apically 2 mm above the bone crest and coronally at the level of the CEJ. It should then be fixed with resorbable single interrupted sutures at the base of the anatomic de-epithelialized papillae.

Flap closure

apical extension of the vertical releasing incisions. It then proceeds coronally with other interrupted sutures, each of them directed from the flap to the adjacent buccal soft tissue. This is done to facilitate the coronal displacement of the flap and to reduce the tension on the last coronal sling suture.

The sling suture permits stabilization of the surgical papillae over the interdental connective tissue bed (the anatomic papillae) and allows for a precise adaptation of the flap margin to the underlying convexity of the crown. At the end of the surgery, the collagen matrix should be completely covered by the flap.

The suturing of the flap starts with two interrupted periosteal sutures at the most

FIG. 1: RECESSION COVERAGE APPROACH WITH SPLIT-FULL-SPLIT THICKNESS FLAP TO GUARANTEE GOOD VASCULARIZATION

Illustration: Quaint

FOR THE TISSUE ON THE ROOT SURFACE

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The use of a coronally advanced flap in combination with the new volume-stable collagen matrix Geistlich Fibro-Gide® can be a valuable option for the treatment of single Miller Class I gingival recessions.

(Fig. 2) The presence of at least 1 mm of keratinized tissue apical to the recession defect is a prerequisite for this surgical strategy to guarantee the stability of the flap in its final coronal position. The adjunctive use of the collagen matrix, capable of incorporating and stabilizing the blood clot above the exposed root surface, provides an increase in soft tissue thickness. This is of paramount importance for the long-term maintenance of the final clinical result.

Literature 1

Cardaropoli G, et al.: J Clin Periodontol 2003; 30,

809–818.

2 Araujo MG, Lindhe J: J Clin Periodontol 2005; 32: 212–218.

3 Hämmerle C, et al.: Clin Oral Impl Res 2012; 23(Suppl 5), 22-38.

4 Schropp L, et al.: Int J Periodontics Restorative Dent 2003; 23:313–323.

5 Cardaropoli D, et al.: Int J Periodontics Rest Dent 2012; 32: 421-430.

6 Vignoletti F, et al.: Clin Oral Implants Res 2012; 23 Suppl 5:22-38.

7 Araujo MG, et al.: Int J Periodontics Restorative Dent 2008; 28:123-135.

8 Avila-Ortiz G, et al.: J Dent Res 2014; 93(10):950-95.

9 Nobuto T, et al.: J Periodontol 2005; 76:1346-1353.

10 Cardaropoli D, et al.: Int J Periodontics Restorative Dent 2015; 35(5):677-85.

11 Cardaropoli D, et al.: Int J Periodontics Rest Dent 2014; 34(2):211-217.

12 Haas R, et al.: Clin Oral Implants Res 1998; 9(2):117-22.

13 Zitzmann NU, et al.: Int J Periodontics Restorative Dent 2001; 21:288–295.

14 Zucchelli G, et al.: J Periodontol 2006; 77(4):

714–21.

15 Zucchelli G, et al.: Int Journal Periodontics Re-

storative Dent 2016; 36(3): 319–27.

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FIG. 2: TREATMENT OF A GINGIVAL RECESSION IN THE ANTERIOR AREA A

B

C

D

E

F

G

Photos: Dr. Martina Stefanini, Prof. Giovanni Zucchelli

Clinical suggestions

| A Baseline situation: 3 mm gingival recession affecting the first upper premolar with 1 mm of keratinized tissue remaining apical to the defect. | B Matrix preparation: the matrix is trimmed to the ideal dimensions (length, height and thickness). The typical “speed bump” shape is created to give the maximum thickness above the root exposure while facilitating the fixation in the lateral sides. | C Flap design and elevation: trapezoidal flap design with 2 horizontal incisions and 2 vertical releasing incisions. The flap is raised with a split-full-split approach in the coronal-apical direction. | D Matrix fixation at the level of the cement-enamel-junction, with single interrupted sutures anchored at the base of the de-epithelialized anatomic papillae. Flap closure: note the tight adaptation of the gingival margin above the clinical crown and the closure of the vertical incisions to avoid any possible leakage of blood from the wound. | E Healing 6 months after surgery: complete root coverage is obtained and optimal blending between the treated area and the adjacent soft tissues. | F-G Baseline and 6 months profile pictures showing the increase in soft tissue thickness.

3-D imaging and superimposition

A new and more accurate measure of soft tissue changes Adjunct Prof. Dr. Tiago Morelli, USA Private practice, Raleigh University of North Carolina, School of Dentistry, Chapell Hill

Quantifying treatment outcomes is the first step towards continuous improvement. A new technique allows accurate and precise measurement of the increase in soft tissue thickness.

The assessment of soft tissue volume has been a challenging obstacle, especially after soft tissue procedures aimed at augmenting soft tissue thickness or to cover exposed root surfaces.

Classifying soft tissue Traditionally, visual inspection and periodontal probes2 have been used to assess tissue transparency and classify gingival biotype. However, it has been shown that visual assessment is associated with misclassification of approximately half of thin-scalloped cases.3 The use of CBCT has been tested and shown to provide more reliable measures.4,5 However, this method also has several drawbacks, including the limitation of linear measurements only, scattering effect that can affect analysis and additional patient exposure to radiation for comparative analysis.

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FIG. 1: VOLUME LOSS IN THE FIRST SIX MONTHS AFTER EXTRACTION OF TOOTH 13 (Superimposed 3-D reconstructed images)

3-D images from digital ­ optical scanning Digital optical scanning and assessment methods have been introduced to measure volume changes of oral tissues over time6,7 and provide a new perspective for measuring and quantifying soft tissue volume longitudinally after reconstruction or regenerative periodontal procedures.

Calibration preclinical and clinical studies demonstrate precision and reliability of this non-invasive method to assess soft tissue volume changes.8,9 Advances in digital optical scanning quality and precision and the use of non-contact, reverse engineering software have provided the potential to not only precisely measure soft tissue changes but also changes in 3-dimensional (3-D) images, providing an additional and visually more comprehensible perspective for clinical research analysis.

Three techniques for superimposition Researchers in the field of regenerative medicine have always been interested in quantifying the effect of treatment on craniofacial morphology. In recent years, 3-D imaging techniques have been used widely in maxillofacial surgery, dental implantology and various other medical disciplines. The 3-D model superimposition can help identify treatment goals, identify ideal treatment modalities, predict treatment results and evaluate treat-

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FIG. 2: VOLUME LOSS AFTER TOOTH ­E XTRACTION. The blue/green volume is lost in the course of bone remodelling after tooth extraction (cross-sectional slice from tooth 13)

ment outcomes. Various techniques have been reported for superimposition of 3-D datasets derived from conventional computed tomography, CBCT, or intra-oral optical scanners. They include: 1. Landmark-based superimposition 2. Surface-based superimposition 3. Voxel-based superimposition.

The validity of the first two superimposition techniques depends on the accuracy of landmark identification and the precision of the 3-D surface models.

In most software, the 3-D differences of the superimposed models are translated into 2D color codes that represent the distance between corresponding points.

However, the quantification of the structural change is not always straightforward.

A new ­technique based on STL data Recently our group developed a technique for superimposing 3-D models

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and accurately quantifying the volume changes after regenerative bone and soft tissue procedures. The technique involves the acquisition of 3-D surface models that can be obtained from CBCT or intra-oral optical scanners.

When utilizing a CBCT dataset, it is necessary to translate the DICOM file originated from the CBCT file to a Standard Tesselation Language (STL) file. For accurate 3-D superimposition, it is mandatory that the files used for superimposition be taken in the same CBCT unit with identical setup. Another important and critical component is the presence of metal in the area to be evaluated. The scatter effect can potentially modify the morphological structure of the 3-D reconstructed model, limiting the precision of the superimposition and ultimately the measurement and quantification of the volume change.

The intra-oral scanner we have used to obtain 3-D reconstructed images for soft tissue analysis is Trios 3® (3-Shape, Copenhagen, Denmark). Trios 3® is a powerful, extremely fast and light scanner.

It works under the principle of confocal microscopy and ultrafast optical scanning. It is powder-free and produces high-quality, in-color (true color) images. In a validation study, Imburgia and collaborators reported that Trios 3® showed a trueness value ranging from 50.2 μm to 67.2 μm and a precision value ranging from 24.5 μm to 31.5 μm.10

A triangular representation of 3-D surface geometry Surface-based registration could qualify as a valid alternative to the commonly used voxel-based approaches used in medical imaging. STL is an open-source, surface-based format, like DICOM for voxel data, and it is easily accessible through most commercial and freeware software applications. Such surface models have

been widely used in industry, particularly in engineering and architecture, for rapid prototyping and computer-aided manufacturing. These 3-D datasets allow for easy information exchange and communication among scientists.

Surface models do not contain volume data, but instead use 3-D surface data that are different from the data obtained from a CBCT or intra-oral scanner – a triangular representation of 3-D surface geometry.

Also, in this case, the form of data, the surface preprocessing (e.g., smoothing, segmentation), the transformation model and the choice of reference structures should be considered as potential sources of error when superimposing surface models.

In a recent study, Gkantidis et al. evaluated 3-D superimposition techniques on various skeletal structures using surface models and concluded that it can provide accurate, precise and reproducible results.11

Measuring volume changes For surface and volume analysis, we used the Geomagic Qualify® software (Raindrop Geomagic, Research Triangle Park, NC, USA) modified to calculate total volume. A precision analysis study using CAD files determined that surface reconstruction using Geomagic Qualify® software provided a reliable analysis with a maximum deviation of 0.06 mm, standard deviation of 0.003 mm and an average error of 0.002 mm.12 Using 3-D models reconstructed from the intra-oral scanner, our average error was 0.04 mm and 0.07 mm, when using 3-D models reconstructed from the CBCT dataset. We used the threepoint registration method as a reference point to superimpose the 3-D surface models. Once superimposed, 3-D analysis was performed, and the distances between corresponding areas were color-coded on the superimposed models for visualization.

The distance between two points can be calculated at any selected point, giving the linear measurement described in most studies using 3-D surface analysis. In order to calculate volume, it is necessary to pre-select the area in the reference model and replicate it into the tested model. Once 3-D analysis is complete, the software algorithm can generate the specific volume difference between the reference and test model.

FIG. 4: 3-D RECONSTRUCTED VOLUME REPRESENTING THE TOTAL VOLUME LOSS POST-EXTRACTION (superimposed over the 3-D reconstructed model at 6 months post-extraction)

Conclusion Advances in digital tools used to obtain 3-D datasets can provide accurate, non-invasive and visually instructive methodologies for diagnosis, treatment planning and evaluation of the efficacy of treatment options, providing the clinician with valuable information for decision-making.

Most importantly, the use of digital technology for the evaluation of treatment outcomes can potentially demonstrate not only the statistical significance between different treatment options but also clinical significance, by visualizing the total volume gain or loss after surgical procedures.

References 1

Seibert J, Lindhe J: Esthetics and periodontal therapy. Munksgaard 1989: 477-514.

2 Kan JY, et al.: Journal of Oral and Maxillofacial Surgery 2009; 67(11): 40-48.

3 Eghbali, et al.: Journal of Clinical Periodontology 2009; 36(11), 958-963.

4 Januario AL, et al.: Journal of Esthetic and Restorative Dentistry 2008; 20(6): 366-73.

5 Amid R, et al.: Arch Oral Biol 2017; 79: 1-6.

6 Thoma DS, et al.: J Clin Periodontol 2010; 37(7): 659-66.

7 Sanz-Martın I, et al.: Clin Oral Implants Res 2016; 27(8): 969-74.

8 Windisch SI, et al.: Clinical Oral Implants Research 2007;18: 545-51.

9 Fickl S, et al.: Journal of Clinical Periodontology 2009; 36: 442-48.

10 Imburgia M, et al.: BMC Oral Health 2017; 17: 92.

11 Gkantidis N, et al.: PLoS One 2015; 23;10(2) : e0118810.

12 Wang WG, Yi J: Applied Mechanics & Materials 2014; 618: 443-47.

FIG. 3: 3-D RECONSTRUCTED VOLUME REPRESENTING THE TOTAL VOLUME LOSS AT 6 MONTHS POSTEXTRACTION

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Missing anterior teeth

How to deal with missing anterior teeth.

Take stock of the situation Prof. Lin Ye, China Peking University, School and Hospital of Stomatology, Department of Oral Implantology

Dental implant therapy is considered a safe and predictable treatment to replace missing teeth.

Nonetheless, implant rehabilitation in the anterior maxilla is still a challenge because of aesthetic concerns.

High predictability and low risk of complication with optimal aesthetic outcome is the primary objective for implant therapy in the aesthetic zone.1 To achieve this goal,

Dr. Jiang Xi, China Peking University, School and Hospital of Stomatology, Department of Oral Implantology

an understanding of biology, clinical principles and technique are fundamental.

Evaluation of aesthetics Objective methods for qualitatively assessing implant aesthetics are crucial for evaluating outcomes, recording clinical data, comparing different studies and associated follow-up periods, and, last but not least, training and education. Three indices have been developed (Fig. 1): 1. The Pink Esthetic Score (PES), which involves only the peri-implant soft tissue.2 2. The modified PES to comprehensively assess the aesthetic outcome of im-

3.

plant reconstruction of both soft tissue and restoration.3 The White Esthetic Score (WES), which specifically focuses on the clinical crown supported by implant.3

The aesthetic indices have been developed mainly on the basis of clinical results, without involving the patient’s opinions. Nevertheless, the concept of oral health care should integrate the patient’s needs with the professional’s point of view, and, therefore, it is important to consider both subjective and objective aesthetic outcomes.

Key to success: Correct 3-D position of the implant

Illustration: Quaint

From both the biological and technical point of view, the 3-dimensional (3-D) implant positioning, and especially the implant shoulder, is one of the most important factors influencing the final aesthetic result. Successful 3-D positioning needs to be performed in relation to the following measures: ›› Mesio-distal, ›› Apico-coronal, and ›› Orofacial.

According to Buser et al., to obtain an optimal aesthetic result the implant shoul-

FIG. 1: PINK ESTHETIC SCORE (PES), MODIFIED PES AND WHITE ESTHETIC SCORE (WES) WITH THEIR VARIABLES

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In the orofacial dimension, implant placement is particularly crucial, and improper application of this principle often leads to detrimental aesthetic results (e.g., gingival recession and aesthetics problems). Therefore, the orofacial positioning guidelines should always be followed whether dealing with a healed ridge or extraction socket. In healed sites, physiological ridge remodeling after tooth loss is characterized by more pronounced bone resorption on the buccal rather than the palatal aspect, resulting in a ridge with adequate bone height only at the palatal side of the implant. Hence, the implant should always be “palatally” placed in the anterior maxilla. However, in case of immediate implants, the extraction socket can be deceptive. Orofacial implant placement in the middle of the extraction socket often intrudes into the facial boundary. Following the rule of correct orofacial dimension, the implant position should be at the palatal wall of the extraction socket.

Timing of implant placement The timing of implant placement is clinically relevant for treatment duration, surgical strategy, aesthetics and patient perception. In 2004 a consensus statement classified the timing of implant placement into four categories (Table 1). With the evolution of our understanding of socket healing biology, the indication of the four types of implant timing needs to be updated, especially for type 1. Indeed, the concept of immediate implant placement developed in 1978 has been a controversial topic for more than 30 years, especially in the aesthetic zone.

Illustration: Quaint

der should be placed within the “comfort zones,” without invading the “danger zones,”4 which are defined mesio-distally, orofacially, and apico-coronally. (Fig. 2)

FIG. 2: CORRECT IMPLANT POSITIONING IN THE MESIO-DISTAL, OROFACIAL, AND APICO-CORONAL DIMENSIONS. Mesio-distal dimension: The implant shoulder should be

positioned within the comfort zone, avoiding the danger zones, which are located close to adjacent root surfaces. In the daily practice, mesio-distally placing the implant in the middle of a single tooth gap in the anterior maxilla is often the correct choice. When the mesio-distal space is limited, small diameter implant of 3.5 or 3.0 mm, might be considerated. Orofacial dimension: The implant shoulder should be placed about 1.5 mm palatal to the point of emergence of adjacent teeth. The danger zone is clearly entered when the implant is placed too facially. A second danger zone is located too far palatally, which can require an implant crown with a ridge-lap design. Apico-coronal dimension: The implant should be positioned 3-4 mm apical to the gingival margin of the future restoration, which means the platform is slightly subcrestally located in the facial aspect and more subcrestally in the interproximal area.

Immediate implant placement involves two biological processes: (1) the healing/ remodeling of the extraction socket, and (2) the osseointegration of the implant.

Clinical studies with large cohorts and long-term follow-up have demonstrated that the survival rate of immediate implants is comparable to implants placed in the healed ridge.5 A recent animal study revealed no differences in the establishment of bone-implant interface at the cellular level when comparing immediate and delayed implant placement.6 Therefore, we can conclude that the microenvironment of an extraction socket does not jeopardize the osseointegration of dental implants.

Meanwhile, both preclinical and clinical studies have proved that placing a titani-

um implant into the socket does not alter the features and processes of socket remodeling.7,8 Therefore, the two biological processes are independent of one another, and they both influence the basic principle of immediate implant placement.

To obtain favorable aesthetic outcomes with long-term stability, immediate implants in the aesthetic zone should include consideration of the following: Implant position. The implant neck should not protrude through the future buccal bone plate after bone remodeling.

Augmentation/ preservation of the ridge profile. According to previous studies, spon-

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taneous socket healing results in the loss of 50% of ridge width. Therefore, the residual bone may not be able to surround the implant circumferentially or maintain enough facial bone thickness. The most commonly used and evidence-based strategy for ridge preservation is intra socket grafting, which preserves 80% of ridge width. With immediate implant placement, the gap between the buccal bone and the implant surface should be filled with a low-substitution rate grafting material (DBBM) to compensate/ counteract socket remodeling, leading to higher bone formation at the buccal-coronal region.9, 10 Immediate provisionalization. Due to the resorption of bundle bone, extraction sockets tend to lose buccal bone within a month, jeopardizing bone volume stability. Pressure from the labial soft tissue can cause gingival collapse into the gap and compromise new bone formation. Therefore, besides the grafting material, a rigid socket sealing system (e.g., an implant-supported temporary crown) supporting the buccal soft tissue can provide additional volume stability.11 Clinical studies have revealed that immediate implant placement combined with immediate provisionalization (IIPP) insures better clinical outcomes than immediate implant placement alone.12

IIPP using flapless technique. A gingival flap is usually raised to facilitate GBR and to achieve better new bone formation buccally. However, cost-effectiveness must be taken into consideration. Besides disturbing the natural gingival form, bone resorption and post-surgery discomfort can also be drawbacks. Current clinical evidence suggests that a reasonable thickness of buccal bone and predictable soft tissue levels over the long-term can be obtained by using intra socket grafting combined with implant supported provisional crowns.

The indication for immediate implant placement is controversial. Previous studies suggest immediate implant placement in the aesthetic zone only with a thick buccal bone wall phenotype (> 1 mm) and a thick gingival biotype. 1 These conclusions were reached by studying CBCT results, which indicated that thin bone phenotypes, exhibiting a facial bone wall thickness of 1 mm or less, produced progressive bone resorption with a vertical loss of 7.5 mm; whereas thick bone phenotypes produced only minor bone resorption with a vertical loss of 1.1 mm.13 The results of these studies are in agreement with our own work.14 However, the deduction that immediate implant placement may not be considered with thin phenotypes is not always appropriate. In-

deed, even if arresting the resorption of thin buccal bone, which is mostly comprised of bundle bone, is not achievable, by using appropriate methods we can regenerate new bone between the buccal bone and the implant surface. Regeneration potential is the key to success for immediate implants.

References 1

Buser D, et al.: Periodontology 2000 2017; 73: 84-102.

2 Furhauser R, et al.: Clin Oral Implants Res 2005; 16: 639-644.

3 Belser UC, et al.: J Periodontol 2009; 80: 140-151..

4 Buser D, et al.: Int Oral MAxillofac Implants 2004; 19: 43-61.

5 Chen ST, et al.: nt Oral MAxillofac Implants 2004; 19 Suppl: 12-25.

6 Watanabe T, et al.: Clin Implant Dent Relat Res 2016; 18: 146-160.

7 Araujo MG, et al.: J Clin Periodontol 2005; 32: 645-652.

8 Botticelli F, et al.: J Clin Periodontol 2004; 31: 820-828.

9 Araujo MG, et al.: Clin Oral Implants Res 2011; 22: 1-8.

10 Groenendijk E, et al.: Int J Oral Maxillofac surg 2017; 46: 1600-1606.

11 Degidi M, et al.: Int J Periodontics Restorative Dent 2013; 33: 559-U515.

12 Arora H, Ivanovski S: Clin Oral Implants Res 2018; 29: 346-352.

13 Chappuis V, et al.: J Dent Res 2013; 92: 195s-201s.

14 Jiang X, et al.: Clin Implant Dent Relat Res 2017; 19: 96-305.

TABLE 1: TIMING OF IMPLANT PLACEMENT Classification

Definition

Indication

Type 1

Immediate implant placement

Intact buccal bone plate; Sufficient bone in the apical region to provide anchorage of the implant

Type 2

Early implant placement with soft tissue healing (4~8 weeks post extraction)

Defect of buccal bone plate; Sufficient bone in the apical region to provide anchorage of the implant

Type 3

Early implant placement with partial bone Multi-rooted molars healing (3~4 months after extraction)

Type 4

Late implant placement with complete healing (over 6 months)

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Delayed implant surgery is required due to personal or anatomic reasons

Read the full article on our blog.

Long-term stability

The biology behind Geistlich Bio-Oss® Associate Prof. Dieter D. Bosshardt, Switzerland Robert K. Schenk Laboratory of Oral Histology School of Dental Medicine, University of Bern

Histologic staining properties, adsorption and uptake of proteins, osteoconductivity, and resorbability – an overview of biological data and longterm stability clinical outcomes to better understand Geistlich Bio-Oss®.

Geistlich Bio-Oss®, a natural, non-antigenic, porous bone mineral matrix of bovine origin, has been commercially available for regenerative dentistry for more than 30 years. But what are the characteristics of this product that guarantee stable and long-term clinical results? Let us take a step back and examine the biology.

Histologic staining properties When Geistlich Bio-Oss® is processed in its native form for the production of undecalcified ground sections and stained with toluidine blue, staining is extremely weak (Fig. 1). Nevertheless, an empty Haversian canal is visible forming a macropore surrounded by lamellar bone, generated through the birefringence of hydroxyapatite (Fig. 2). After placement of Geistlich Bio-Oss® in an augmentation site, an undecalcified ground section stained with toluidine blue demonstrates completely different characteristics.

The biomaterial is much more intensely stained than the surrounding bone (Fig. 3),1 indicating the presence of organic material. Based on this comparison we can conclude that Geistlich Bio-Oss® has taken up organic components such as endogenous proteins, which could enhance biofunctionality and contribute to biocompatibility. Also, the presence of endogenous proteins can be observed when staining is performed on decalcified sections before embedding and cutting.1 Indeed, both the resin (Fig. 4; toluidine blue and basic fuchsin) and the paraffin sections (Fig. 5; hematoxylin & eosin) reveal a slightly darker staining of new bone and subtle shades of blue and red for Geistlich Bio-Oss®.

Adsorption and uptake of proteins Protein adsorption plays a key role in determining the initial cell response to an implanted biomaterial, which is immediately coated with proteins and other molecules from blood and tissue fluids. The uptake of endogenous proteins can be demonstrated using high-resolution immunohistochemistry with an antibody for typical bone-related noncollagenous proteins, the abundance of which is indicated by gold particles that turn into black dots in the image shown in Figure 6. Geistlich Bio-Oss® can also be pre-coated with exogenous proteins with biological activity. In vitro, Geistlich Bio-Oss® retains enamel matrix pro-

FIGS. 1-3: Undecalcified ground sections of Geistlich Bio-Oss® spongiosa particles embedded in

methyl methacrylate before (1, 2) and after (3) implantation into the body, stained with toluidine blue and viewed under transmitted (1, 3) and polarized light (2).

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teins (Emdogain®, Straumann AG, Switzerland – Fig. 7)2 as well as Osteogain®3 (Straumann AG, Switzerland), a liquid formulation of Emdogain®. These findings demonstrate that Geistlich Bio-Oss® can function not only as a bone substitute biomaterial filling the bone-defect and promoting bone formation through osteoconduction, but also as a carrier delivering exogenous proteins with biologic activity.

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Osteoconductivity Numerous studies have demonstrated the osteoconductivity of Geistlich BioOss®.4-6 Indeed, when it is placed close to or into a bony environment, osteoblasts can deposit bone matrix directly onto the biomaterial (Fig. 8).

Resorbability FIGS. 4, 5: Resin (4) and paraffin (5) section of a decalcified human superficial tissue sample. The

Geistlich Bio-Oss® particles demonstrate good osseointegration and reveal a differential staining pattern.1

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One of the characteristics of Geistlich Bio-Oss® is its resistance to resorption.4-6 The particles are frequently covered by osteoclast-like multinucleated giant cells (MNGCs), and the implica-

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FIG. 6: Immunohistochemistry of an ultrathin tissue section of a human

FIG. 7: Immunohistochemistry of Geistlich Bio-Oss® precoated with

biopsy containing Geistlich Bio-Oss embedded in acrylic resin to demon-

enamel matrix proteins (Emdogain®).

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strate the uptake of non-collagenous proteins.

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tion of the MNGCs has been studied.7-9 Osteoclasts can be labeled for tartrate-resistant phosphatase (TRAP), an enzyme typically, but not exclusively, expressed in osteoclasts. MNGCs on Geistlich Bio-Oss® embedded in bone

are consistently TRAP-positive (Fig. 9).

The Geistlich Bio-Oss® surface under these MNGCs is predominantly flat and does not reveal signs of resorption (e.g., Howship’s lacunae – Fig. 10). Very rarely, however, shallow concavities

8

reminiscent of Howship’s lacunae can be seen under these MNGCs (Fig. 11), indicating a resorptive activity.10-13 Under which specific conditions resorption of Geistlich Bio-Oss® occurs is still unclear and requires more research.

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FIG. 8: Resin section of a human biopsy containing Geitlich Bio-Oss® illustrating the very initial

FIG. 9: Histochemical staining for TRAP (red

deposition of bone matrix to the Geistlich Bio-Oss® surface.

staining) identifies osteoclast-like, MNGCs on the surface of Geistlich Bio-Oss® particles.

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FIGS. 10, 11: Decalcified tissues embedded in resin and stained with toluidine blue. MNGCs (arrow) are frequently observed without obvious signs

of resorptive activity (e.g. Howship‘s lacunae) (10). Occasionally, shallow concave indentations (arrows) can be seen under the MNGCs, suggesting resorptive activity (11). Thin seam (*).

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Possible reasons include inflammation and displacement of the particles away from the augmentation site, but other co-factors may be involved as well.10-13 For example, researchers have demonstrated normal resorption and replacement of Geistlich Bio-Oss® with orthodontic tooth movement.14

Long-term stability in the aesthetic area Human biopsies harvested after sinus floor elevation offer an ideal opportunity for histologic analysis, since they can be collected non-invasively. In a recent article, Jensen et al. have shown histologic and histomorphometric data in 12 biopsies from ten patients harvested 14

to 80 months after dental implant placement with simultaneous contour augmentation.15 Before this publication no human histologic data were available to document the tissue reactions to bone augmentation procedures with autologous bone and Geistlich Bio-Oss®. Most xenogeneic particles were embedded in mature bone, and no inflammatory reaction was observed. On average, 40.6% of the augmented area was occupied by bone, 32.0% by Geistlich Bio-Oss®, and 27.4% by soft tissue (Fig. 12), and there was no tendency toward a decreasing area fraction of Geistlich Bio-Oss® over time. In addition, 70.3% of Geistlich Bio-Oss® particle surface area was covered with bone (i.e., osteoconductivity

12

%

– Fig. 13). These data demonstrate stable long-term conditions and support previous clinical and radiographic data showing stable peri-implant soft tissues for up to nine-years, with an intact facial bone wall in 95% of the cases.16-19 The data also indicate that neither the presence of MNGCs nor their positive staining for TRAP correlate with resorption rate. Very recently, biopsies with Geistlich Bio-Oss® harvested from a patient 20-years after sinus floor elevation were analyzed histologically.20 The results show that Geistlich Bio-Oss® particles and MNGCs are still present after 20-years (Figs. 14-16), with the particles embedded in mature trabecular bone exhibiting mature bone marrow.

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FIGS. 12, 13: Histogram illustrating the area fractions of bone, and Geistlich Bio-Oss® (12), and the percentages of Geistlich Bio-Oss® surface covered

with bone (13). In total, 12 biopsies from ten patients harvested 14 to 80 months after a GBR procedure.15

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References 1

Bosshardt DD: Quintessence, Berlin, Germany

2014: 135-144.

2 Miron RJ, et al.: J Periodontol 2012; 83: 936-47.

3 Miron RJ, et al.: J Periodontol 2015 ;86: 578-87.

4 Jensen SS, et al.: Clin Oral Implants Res 2006; 17:

237-43.

5 Jensen SS, et al.: Clin Oral Implants Res 2007; 18:

752-60.

6 Jensen SS, et al.: J Biomed Mater Res Part B: Appl

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Biomater 2009; 90:1 71-81.

7 Miron RJ, Bosshardt DD: Biomaterials 2016; 82:

1-19.

8 Miron RJ, et al.: Acta Biomaterialia. 2016; 46: 15-

28.

9 Miron RJ, Bosshardt DD: Tissue Eng Part B Rev

2018; 24: 53-65.

10 Jensen SS, et al.: Clin Oral Implants Res 2015; 26:

859-64.

11 Busenlechner D, et al.: Clin Oral Implants Res

2012; 23: 95-99.

12 Jensen SS, et al.: Clin Implant Dent Relat Res

2015; 17: 274-85.

13 Janner SFM, et al.: Clin Oral Implants Res 2017;

BO

28: 1368-80.

14 Araújo MG, et al.: J Clin Periodontol 2001; 28:

73–80.

15 Jensen SS, et al.: J Periodontol. 2014 ; 85: 1549-56.

16 Buser D, et al.: J Periodontol 2009; 80: 152-62.

FIGS. 14-16: Histology demonstrating integration of Geistlich Bio-Oss® particles in trabecular

17 Buser D, et al.: J Periodontol 2011; 82: 342-49.

bone 20-years after sinus floor elevation. (14, 15) Geistlich Bio-Oss® particles are interconnect-

18 Buser D, et al.: J Periodontol 2013; 84: 1517-27.

ed by bone matrix and surrounded by mature fatty bone marrow. (16) A large MNGC (arrow) is in direct contact with the biomaterial. Paraffin section (14), resin sections (15, 16).20

19 Buser D, et al.: J Dent Res 2013; 92(12 Suppl):

176S-82S. 20 Valentini P, Bosshardt D: Int J Oral Maxillofac

Impl 2018. Ahead of print.

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Predictable treatment in challenging cases

Use of Yxoss CBR® in the anterior area Prof. Frank Liebaug, China & Germany Shandong University, Jinan, China Ellen Institute, Steinbach-Hallenberg, Germany

The disadvantages of bone blocks for large bone augmentation are significant – graft resorption, harvest site morbidity, poor graft integration and limited blood supply. Yxoss CBR® provides an alternative approach using particulate graft material.

Due to the incorrect positioning or alignment of implants, implant placement in non-augmented residual bone frequently leads to aesthetically unfavourable and problematic restorations.1

The objective of a GBR procedure, therefore, is the successful regeneration of bone in a defect area with high reliability and a low rate of complications.2 In the last decade, researchers and clinicians have focused increasingly on achieving success with a therapy that entails as few surgical procedures as possible, a low level of patient morbidity and a short healing period.

Although the biological basis of bone regeneration is constant, there are variable defect presentations – e.g., defect morphology, scaring and inflammation – which require different treatment approaches. Today we know that ideal regenerative bone bed conditions tolerate less than ideal regenerative augmentation materials, but less than ideal bone beds require ideal, biologically regenerative bone materials.

Space, time and rest are key Large, three-dimensional defects continue to present a challenge in the world of everyday implant surgery. Conventional block augmentations are associated with patient morbidity. In addition, insufficient revascularisation and bone block resorption during the initial course of healing, or long-term, can jeopardize treatment success.3 Alternatives to bone blocks have included non-resorbing membranes reinforced with titanium mesh.

The new titanium scaffold Yxoss CBR® is a good solution for bone defects that require improved regenerative potential and positional stability. The goal is to provide regeneration equivalent to autologous bone blocks but with better handling and reduced morbidity.

FIG. 1: TREATMENT OF A COMBINED DEFECT IN THE ANTERIOR AREA: The 56-year old female patient has a bone defect in the anterior maxilla and

desires a fixed reconstruction. She rejects ridge augmentation with an autologous bone block, because she does not want to have a second surgical site.

She has scar tissue around tooth 12 and discoloration around tooth 11, due to metallic ions from a restoration. The plan is to augment bone in areas 11 and 12 with Yxoss CBR® immediately after extraction of tooth 11.

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| A Intra-oral situation after alio loco extraction of tooth 12. Also tooth 11 is to be removed before the new prosthetic restoration because of a former root tip resection and additional periodontal bone loss. Visible scarring and discoloration of the marginal gingiva suggest malnutrition. | B Preview image sent by ReOss, which must be confirmed or amended by the treatment provider. Tooth 11 – not yet extracted – was virtually erased by the planning team. | C Status following extraction of tooth 11 with no signs of alveolus fracture. | D The prefabricated titanium basket fits into the defect with positional stability. | E Filling of the mesh with a 1:1 mixture of autologous bone, collected by SafeScraper®, and Geistlich Bio-Oss®, grain size 1-2 mm. | F Following placement of the collagen membrane over the mesh and adaptation to the margins below the mucoperiosteal flaps, the dampened membrane clings to the titanium mesh. | G Tension-free primary wound closure, using a modified vestibule flap with 5-0 suture. | H Temporary crowns placed immediately after surgery, pictured after 10-days. | I Breaking the mesh with a periosteal elevator at the pre-defined breaking point. | J Occlusal view after insertion of single-stage implants. | K Partial panoramic view after the insertion of two, single, full ceramic implants (ceram® implant 4.5 x 12 mm, Vitaclinical, Germany) 6 months later. | L Clinical situation and ceramic crowns over single-stage, ceramic implants in area 12 and 11 without bone loss, gingival dehiscences, inflammation or bone block harvest. The patient is satisfied with the treatment result.

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Yxoss CBR® – Customized Bone Regeneration The Yxoss CBR titanium scaffold is customized using a CAD/CAM procedure based on patient CBCT records. One advantage of this customized configuration is that bone dimensions for subsequent implant placement can be pre-planned and achieved.

The patient data gathered with CBCT is forwarded to the company ReOss (Filderstadt, Germany) as a DICOM file. ReOss then emails a planning or design proposal for the titanium mesh, which the clinician can accept or amend. ReOss then creates a highly accurate titanium mesh for the individual bone defect. It is also possible to design meshes before tooth extraction, so that the Yxoss CBR® bone augmentation can be performed immediately after tooth extraction, which is what usually happens in our practice.

the customized mesh does not have a barrier function, the use of a collagen membrane between the titanium mesh and mucoperiostal flap is critical.

In the case of defects greater than two teeth, two layers of collagen membrane are used so as to achieve a sustained barrier function and protect the defect area from ingrowing soft tissue cells.

Clinical tips Stress-free primary wound-closure: To enable a stress-free primary wound closure after major volume augmentation, the periosteum must be separated from the underlying bone. The flap should also be mobilized lingually or palatally, as the three-dimensional titanium mesh encloses the alveolar ridge.

Primary wound closure is achieved with deep mattress sutures and single interrupted sutures.

riod of nine to twelve months might be necessary in order to achieve complete regeneration.

Concluding remarks The surgical technique presented here allows for predictable bone regeneration in patients with larger, three-dimensional bone defects. Compared to autologous bone blocks, treatment is less invasive, and the surgery time is shorter. Even in a complex, three-dimensional alveolar bone defect, the combination of autologous bone chips and bone replacement material generates a stable, augmented volume and, therefore, promises a more predictable outcome for patients.

Overall, implants can be placed ideally for prosthetic restoration (“prosthetically-driven implant placement”).

References 1

“Compared to the use of autologous bone blocks, treatment is less invasive and the surgery time is shorter.”

The titanium scaffold does not function as a membrane or barrier but simply as a stable basket or cage. Before placement in the bone defect, it is filled with a mixture of autologous bone chips, collected by SafeScraper®, and particulate bone replacement material (Geistlich Bio-Oss®). The combination provides both volume and regenerative capacity for the defect area.

Although the ideal ratio autologous bone to bone substitute is 1:1, good bone regeneration has also been observed with a ratio of 1:2 in our practice. Since

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Protecting the soft tissue: Should dehiscences at the wound margins occur, they should be de-epithelialized as far as possible and adapted with new sutures, or at least treated with chlorhexidine gel over an extended time frame. To prevent additional pressure necroses, we recommend in-situ dentures over the augmentation area to create adhesive bridges without mucosa-positioned, interim prosthesis.

Sufficient healing time: The healing period is approximately six months.4 With pronounced defects, a longer healing pe-

Gehrke P, et al.: Implantologie 2008; 16: 131-39.

2 Liebaug F, Wu N: Implantologie Journal 2010; 7: 34-37.

3 Seiler M, et al.: Oralchirurgie Journal 2016 ; 1 : 26-29.

4 Liebaug F, Liebaug A: Teamwork 2016; 5: 2-8.

Case study

Sequential extractions and implantations Dr. Philippe Khayat, France Associate Affiliate Professor University of Washington, USA Private practice Paris, France

Multiple immediate implants and extensive treatment in the maxilla.

Stay in control and simplify therapy to prevent peri-implantitis.

A 38-year-old female presented during our consultation hours because she could not chew efficiently and was afraid of losing her upper right canine. Her medical history was uneventful. For several years she had been treated and maintained by her periodontist and her oral hygiene was good. However, several teeth showed increased mobility and tooth 13 was about to be lost. (Fig. A) Despite rather severe bone loss (Fig. B) and the malposition for tooth 13, tooth migration or diastemas were not present. Because of her periodontal condition, we informed the patient of her higher risk for peri-implantitis.1 Indeed, although with good peri-implant maintenance therapy this type of patient could be treated successfully, the risk for peri-implantitis remains significant.2 The first phase of treatment was performed as if it were four single tooth extractions/ implantations. Implants were placed as teeth were removed incrementally. This sequence allowed retention of anatomical landmarks during surgery. A surgical guide (basic vacuum-formed stent) was fabricat-

Dr. Marin Pomperski, France Private practice Paris, France

ed but not used extensively. Modified titanium fixture mounts were used as immediate provisional abutments, since they are stronger and easier to prepare than polyether ether ketone. (Figs. C, D) A 9-unit methyl methacrylate temporary bridge was relined immediately, trimmed, finished and delivered within three hours.

This bridge reproduced the shape and position of the patient’s teeth.

The aesthetic result was obtained by combining two shades of resin (incisal and dentin, Unifast III, GC) and the use of chairside glaze with stains (OptiglazeTM, GC, and Akzent®, VITA). The incisal embrasures were deep and could compromise strength and rigidity; therefore, we compensated by using thick pink acrylic gingiva. (Fig. E) The bridge was cemented and excess cement was removed carefully. (Fig. F) A sinus graft was performed a few weeks later (Fig. G) and, after a six-month healing period, tooth 15 was removed and two posterior implants were placed. Remaining maxillary molars showed moderate bone loss and no mobility and, therefore, they were retained. (Fig. H) After healing, an indirect impression (closed tray) was taken. A porcelain fused to metal bridge was fabricated in three parts and splinted with low-fusing solder joints (laboratory: Frédéric Briffaut and Philippe Amiach). (Fig. I) The final bridge com-

bined screw-retained and cemented elements (RelyXTM, 3M or Improv®). It was very stable, allowed ideal anatomy for the anterior units and ease of removal. Pink porcelain provided gingival embrasures around implants and allowed proper use of interdental brushes. (Fig. J) The patient was satisfied with the aesthetic and functional outcomes. (Fig. K) Periodontal and peri-implant maintenance appointments were scheduled (four-month recalls).

All-on-4 or sinus grafts and six implants?

When teeth remain in the maxilla, oblique implant placement with an All-on-4 approach should be questioned. The oblique implant has to cross several extraction sockets, and healing may not be predictable. If primary stability is not optimal, the prognosis may also be poor. Many All-on-4 cases are described for fully edentulous patients with healed crestal bone. Our patient’s sinuses were healthy and presented with a favorable anatomy, so sinus grafts provided an excellent prognosis.3 In this case placement of two long and wide posterior implants was possible.

References 1

Chrcanovic BR, et al.: J Dent 2014; 42(12): 1509-27.

2 Monje A, et al.: J Dent Res 2016; 95(4): 372-9.

3 Esposito M, et al.: Eur J Oral Implantol 2010; 3(1): 7-26.

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FIG. 1: CASE STUDY OF AN IMMEDIATE IMPLANT PLACEMENT WITH AN EXTENSIVE TREATMENT IN THE MAXILLA A

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| A Initial clinical situation. | B Significant bone resorption in the maxilla. | C Four single tooth extractions/ implantations. | D Panoramic radiograph after the first treatment phase. | E Pink acrylic resin provides added strength and rigidity. | F Immediate aesthetic outcome. | G Sinus graft procedure. | H Radiograph at 6-months follow-up: two more implants are placed. | I 11-unit PFM bridge on six maxillary implants. | J Final positioning of the bridge. Porcelain allows the use of interdental brushes. | K Final panoramic radiograph.

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Case case

Facing dehiscence defects in the anterior area Dr. Shakeel Shahdad, UK Consultant and Honorary Clinical Senior Lecturer in Restorative Dentistry at The Royal London Dental Hospital and, Queen Mary University of London Private Practice, London, UK

Soft tissue defects are often encountered prior to implantation, resulting in insufficient attached keratinized mucosa, which, if not corrected, results in less than ideal aesthetic outcomes.

Recently a two-layer, porcine-derived collagen matrix (Geistlich Mucograft®) has been investigated for the treatment of dehiscence defects around teeth and for augmenting keratinized tissue around teeth and implants supporting fixed prosthetic restorations.1-4 The matrix is composed of type I and type III collagen and is thicker than conventional collagen membranes. Intraoral soft tissue

around the periphery of the graft grows through, rather than under, the matrix, as it is replacing it.

A 62-year old healthy, non-smoker male presented with a 7 mm “v” shaped gingival recession defect extending to the apex of the upper left central incisor (Fig. A, B). There was no underlying medical history of any significance. The tooth

FIG. 1: CASE STUDY OF A MILLER CLASS III RECESSION DEFECT B

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| A Pre-operative photographs demonstrating Miller Class III recession defect in 21. | B Radiograph showing previous apicoectomy surgery, and a leaking post-crown. | C Extraction socket with missing labial bone plate, and inter-dental bone loss at 22. | D Haemostatic plug placed in extraction socket to prevent collapse of Geistlich Mucograft®. | E Geistlich Mucograft® adapted under the flap and extended into palatal pouch. | F Graft sutured using single interrupted sutures without any attempt to achieve primary closure or submerge Geistlich Mucograft® underneath the flap. | G Healing after 1 week.

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| H Healing after 6 weeks. | I Surgical exposure of the site showing complete loss of buccal bone including loss of interdental bone in 22. | J Ideal 3-dimensional placement of dental implant. | K Geistlich Bio-Oss® mixed in blood placed on top of autologous bone chips to augment the missing buccal bone. | L Geistlich Bio-Gide® in place. | M Healing after 1 week post implantation. | N Healing after 8 weeks immediately prior to abutment connection surgery. | O Pink aesthetics optimized with a provisional crown. | P Definitive restoration after 2 years. | Q Definitive restoration after 5 years in function. Peri-implant soft tissues are stable despite recession in natural teeth. | R Peri-apical radiograph after 4 years. | S CBCT scan of the implant demonstrating regeneration and maintenance of labial bone at 4-year review.

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was failing endodontically with a previous root filling and apicoectomy surgery.

The upper left central incisor was atraumatically extracted, followed by removal of granulation tissue from within the socket. A small pouch was created and extended a few millimeters beyond the intact bone margins. Complete loss of the buccal plate was noted, and in order to prevent collapse of the graft, a collagen haemostatic plug was placed in the extraction socket (Hemospon Collagen CubesTM, TechNew, Brazil). Geistlich Mucograft® was cut to size so that the edges extended beyond the bone margins to ensure coverage by the overlying flap. It was stabilized to the overlying flap margins with 6-0 monofilament nylon interrupted single sutures (Figs.

C-F). A provisional resin-bonded bridge was cemented, avoiding contact with the

the buccal plate was noted. Nonetheless, there was apical bone to the floor of the nose to offer adequate primary stability (Fig. I).

A Straumann® SLActive (Straumann AG, Switzerland), Tapered Effect, tissue-level type implant was placed in an ideal 3-dimensional position, resulting in a 6 mm dehiscence of the roughened surface of the implant. Following corticitomy, autologous bone shavings were collected from the adjacent area and placed over the implant, followed by blood soaked deproteinized bovine bone substitute (Geistlich Bio-Oss®), which was covered by a bi-layered porcine-derived collagen barrier membrane (Geistlich Bio-Gide® – Figs. J-L). The sutures were removed after one-week (Fig. M), and the implant exposure surgery was carried out after eight weeks using a 4 mm soft tis-

peri-implant soft tissues and optimal pink and white aesthetics were noted.

The mucogingival line was corrected, and 5 mm of keratinized mucosal width was restored (Figs. P, Q). Radiographs demonstrated stable bone levels, and a CBCT scan revealed a maximum labial bone thickness of 3.6 mm.

In total, 1.6 mm labial bone thickness was noted at the junction of the SLA surface and the smooth collar, and the bone extended vertically beyond this junction, albeit not in contact with the implant surface (Figs. R, S).

References 1

Lorenzo R, et al.: Clin Oral Implants Res 2012,

23(3): 316-24.

2 Sanz M, et al.: J Clin Periodontol 2009; 36(10): 86876.

3 McGuire MK, Scheyer ET: J Periodontol 2016; 87: 221-227.

4 Cardaropoli D, et al.: L Periodontol 2012; 83(3):

“After five years Geistlich Mucograft guarantees a stable peri-implant soft tissue and an optimal pink and white aesthetic.”

®

soft tissues or graft.

An uneventful healing was noted at oneweek, with Geistlich Mucograft® showing some surface sloughing similar to the healing anticipated with a free gingival graft (Fig. G). The sutures were removed, and the patient was advised to continue using 0.2% chlorhexidine thrice daily and refraining from tooth brushing around the surgical site. After six-weeks of healing (Fig. H), an early delayed (Type II) implant placement protocol was used in conjunction with simultaneous guided bone regeneration. Complete loss of

321-8.

sue punch (Fig. N).

A laboratory-made implant provisional crown was used for manipulation of soft tissues to optimize the pink aesthetics (Fig. O).

Endodontic treatment in upper right central incisor was revised and non-vital, and in-out bleaching was carried out with concomitant home bleaching in the remaining maxillary dentition. After optimizing pink aesthetics, a screw-retained, one-piece, metal-ceramic crown was provided.

After two- and five-years, stable

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JOURNAL CLUB

MILESTONE STUDIES.

Photos: © iStock.com/dtmiraos

An overview about preclinical and clinical studies to understand the scientific principles and the clinical evidence for stem cells.

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Prof. André Antonio Pelegrine São Leopoldo Mandic Institute and Research Center Campinas, Brazil

Dr. Antonio Carlos Aloise São Leopoldo Mandic Institute and Research Center Campinas, Brazil

In 1963 a Canadian team Stem Cells for Periodontics published a striking article on hemaPeriodontal Regeneration topoietic stem cells. It highlighted the Preclinical study. Reconstruction of the periodontal tissues lost to ability of murine hematopoietic tissue progressive periodontal disease has always been one of the main cells to differentiate into three distinct objectives of research in periodontics. A study conducted in mini pigs by Fu et al. demonstrated that periodontal regeneration can strains: erythrocytic, granulocytic and be achieved more predictably by using a hydroxyapatite/ tricalcimegakaryocytic phenotypes. A few years um phosphate (HA/ TCP) scaffold loaded with stem cells from the later Friedentstein et al. discovered and periodontal ligament or the pulp of deciduous teeth, when comcoined the definition for mesenchymal pared to the carrier (HA/ TCP alone). The authors observed the stem cells, which are adult stem cells with formation of new cementum, periodontal ligament and alveolar bone around teeth surfaces that were previously exposed due to the potential to differentiate into several induced periodontal disease. somatic lineages. These cells were cat egorized as adherent with a fibroblast Clinical study. A major challenge in the practice of periodontics is reconstruction of interdental papillae. The absence of papillae creappearance and able to differentiate into ates undesirable effects such as interproximal black holes (known osteocytes, chondrocytes, adipocytes, as black triangles), which may have both aesthetic and often functenocytes, and myocytes (Fig. 1). tional repercussions. Yamada et al. achieved an average gain of INTRODUCTION

Recognizing stem cells’ ability to differentiate into different tissue types has paved the way for regenerative medicine - the process of replacing or regenerating human cells, tissues or organs to restore normal function. Regenerative dentistry is one branch of regenerative medicine aimed at replacing damaged oral tissues, e.g., enamel, dentin, pulp, cementum, periodontal ligament and alveolar bone.

Preclinical and clinical studies are ongoing to demonstrate the basic scientific principles and the clinical evidence for stem cells.1,2 References 1

Becker AL, et al.: Nature 1963;197(4866):452-454.

2 Friedenstein AJ, et al.: Transplantation 1968;6:230-247.

more than 2.5 mm in interdental papillary tissue in patients treated in a four-year clinical study using mesenchymal stem cells associated with platelet-rich plasma and hyaluronic acid. These results launched a new therapeutic possibility for the treatment of interdental papillae, traditionally considered unpredictable, as well as for regenerative periodontal treatment in sites affected by periodontal disease.

Fu X, et al.: J Periodontol 2014; 85(6): 845-851.

Yamada Y, et al.: J Tissue Eng Regen Med 2015; 9(3): 305-309.

Stem Cells for Implant Dentistry Bone Regeneration Preclinical study. The success of implant-supported dental rehabilitation depends on osseointegration, which can only be achieved when the bone volume is sufficient. A study performed in rabbits by Coelho de Faria et al. evaluated osseointegration and bone growth patterns with appositional grafting. The researchers compared regions grafted with hydroxyapatite combined with bone marrow or adipose tissue-derived stem cells to hydroxyapatite or saline solution alone. Histomorphometric analyses showed that stem cells improved new bone formation as well as osseointegration – and bone marrow cells induced higher gains than stem cells derived from adipose tissue. (Fig. 2)

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FIG. 1: STEM CELL DIFFERENTIATION CASCADE. In general, stem cells

are defined by their ability to remain undifferentiated for a prolonged period of time, while retaining the potential to differentiate into single-line (unipotent / precursor cells), multiple lineage (multipotent) or three primary germ layers (pluripotent). Stem cells may be isolated from adult tissues but are mainly isolated from embryos, and they are maintained in culture as undifferentiated cells. These embryonic stem cells have the ability to generate all cells in adult individuals and are described as Illustration: Quaint

pluripotent, whereas adult stem cells are considered uni- or multipotent, as they have a strong commitment to their primary germ layer.

A

These results showed that stem cells from different sources yield different outcomes. Especially in bone tissue, stem cells from the bone marrow appear more prone to osteogenic differentiation than cells from adipose tissue.

Clinical study. A study by Katagiri et al. indicates the importance of the culture medium for mesenchymal stem cells. In fact, in vitro and in vivo results indicated the presence of several growth factors and cytokines in the medium that increased cell mobilization, angiogenesis and osteogenesis. Eight patients who required bone reconstruction prior to implant placement were enrolled. They achieved promising regenerative results with no local or systemic complications and lower levels of inflammatory markers, as well as higher osteogenic potential, when compared to control. Such findings highlight the potential of this cellular "broth" as a medium for bone reconstruction and promising therapy for the triad of bone tissue engineering: osteoconduction, osteoinduction and osteogenesis.

B

FIG. 2: HISTOMORPHOMETRIC ANALYSES. (A) Adipose tissue's stem

cells. (B) Bone marrow's stem cells. Red = newly formed bone; blue/ white = non-mineralized tissue; ocher = remaining graft particles; black = titanium. Histology (B) reveals better contact between the newly formed bone and titanium (osseointegration). Magnification: 100x.

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GEISTLICH NEWS 2-2018

Coelho de Faria AB, et al.: Int J Oral Maxillofac Implants 2016; 31(6): e155-e161.

Katagiri W, et al.: Head and Face Med 2016; 15: 12-15.

Stem Cells for Endodontics Regeneration of the Dentin-Pulp Complex Preclinical study. Stem cell therapy is a likely strategy for regenerating the dentin-pulp complex and both restoring and maintaining functional teeth. Zhu et al. evaluated the efficacy and safety of pulp stem cell transplantation. The researchers used granulocyte colony-stimulating factor (G-CSF) to induce the formation of mobilized dental pulp stem cells (MDPSCs).

Autologous transplantation of MDPSCs with G-CSF into pulpless teeth in dogs regenerated the pulp tissue. In vitro results also confirmed the combined trophic effects of MDPSCs and G-CSF on cell migration, antiapoptosis and immunosuppression. Moreover, the researchers found no significant age/ donor-related changes in biological properties, such as stability, regeneration potential and expression of senescence markers.

On the other hand, MDPSCs with G-CSF induced less pulp regeneration in elderly dogs compared to young dogs. The authors established the preclinical safety, viability and efficacy of pulp regeneration, opening up the possibility for establishing and standardizing regulatory guidelines for stem cell therapy in clinical endodontics.

Clinical study. Meschi et al. performed an immuno-histochemical study on a single immature and endodontically infected permanent human tooth after a regenerative endodontic procedure (REP). The lower right premolar of a ten-year-old girl underwent a REP, and eleven months after treatment, the tooth was removed for orthodontics. After staining with hematoxylin-eosin, they selected four immunomarkers: neurofilament, pan-cytokeratin, osteocalcin, and CD34. The immunohistochemical analysis revealed the formation of an intracanal connective tissue with regular physiology, though with no typical morphological features of dental pulp. The authors concluded that REP might resolve a periapical infection and result in a combination of regeneration and repair of the dentin-pulp complex in an immature and infected permanent tooth.

Zhu X, et al.: Tissue Eng Part C Methods. 2018 Feb; 24(2):108-120.

Meschi N, et al.: Clin Oral Investig. 2016 May;20(4):807-14.

“A significant effort is ongoing to identify and characterize tooth stem cells and revel their developmental characteristic.�

Stem Cells for Oral Maxillofacial Surgery Maxillofacial Regeneration (Cleft palate) Preclinical study. Korn et al., using a cleft palate model in rats, compared the effect of a hydroxyapatite beta-tricalcium phosphate scaffold with either undifferentiated mesenchymal stem cells or osteogenic differentiated mesenchymal stromal cells. Unmodified scaffolds and unfilled defects (control) were used as well. The results demonstrated incomplete bone formation in all groups; however, in the two cell-based therapy groups, closure of the bony defect was significantly greater than control groups. The authors concluded that in artificial bony defects tissue-engineered bone grafts could induce more pronounced bone formation compared to unfilled controls or scaffolds alone.

Clinical study. Is bone marrow-derived stem cell therapy safe and effective for regenerating large alveolar defects in patients with a history of cleft palate or craniofacial trauma? 18-patients (ten with traumatic injuries and eight with cleft palate) missing teeth associated with horizontal alveolar bone deficiencies were included in a randomized clinical trial by Bajestan et al. Patients received either autologous block grafts or stem cell therapy. Four months after treatment the mean gain in bone width for stem cell sites was almost double that found in the control group. For both groups, the bone gain was higher in trauma patients compared to patients with cleft palates. The researchers successfully placed implants in five out of the ten patients in the stem cell therapy group, and in all eight patients from the control group. The authors concluded that the use of stem cells to treat large alveolar defects was safe, though their ability to completely reconstitute large alveolar defects was limited.

Korn P, et al.: J Craniomaxillofac Surg. 2014;42(7):1277-85.

Bajestan MN, et al.: Clin Implant Dent Relat Res. 2017;19(5):793-801.

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OUTSIDE THE BOX

The Pallid Marvel of Regeneration

Photo: iStock / Argument

Axolotls are able to regenerate not only their limbs but also their eyes and even parts of their heart in just a few weeks. Now international scientists have succeeded in sequencing the salamander’s full genome.

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GEISTLICH NEWS 2-2018

Dr. Klaus Duffner

“Never really grew up” is a characterization that some adults have to live with until they “act their age.” For Mexican axolotls (Ambystoma mexicanum) this is no metaphor but reality. The approximately 25 cm long colorless salamanders actually spend their entire lives in a gill breathing, larval stage underwater. Owing to a congenital thyroid defect, the little critters do not undergo any metamorphosis but nevertheless achieve sexual maturity.

What makes axolotls special, however, is their extreme regenerative capacity. If the animals lose a body part, it takes them just a few weeks to regenerate a perfect replacement including bones, muscles and nerves in situ. Even a full-grown axolotl has the capacity to regrow a severed leg, its entire tail, a section of jaw, a severed spinal cord, a missing eye or even parts of the heart, in the space of a few weeks. Researchers assume a marked penchant toward cannibalism to be a key reason for an axolotl’s extreme regenerative capacity. Regrowing bitten-off limbs and nerves would appear to be a crucial evolutionary advantage for this approximately 350 million year old species of amphibian.

Ten times the size of the human genome To better understand axolotl’s regenerative capacity, scientists needed to know the full DNA sequence. But the axolotl’s genome makes for a particular challenge, because at 32 billion base pairs it eclipses the human genome by a factor of at least ten. It also features a substantial number of long, repeating sequences, which further complicate research. An international research team, led by Elly Tanaka of the Research In-

stitute for Molecular Pathology in Vienna, Eugene W. Myers of the Max-Planck Institute in Dresden and Siegfried Schloissnig of the Heidelberg Institute for Theoretical Studies (HITS), has nevertheless recently managed to fully sequence the axolotl’s genome. Researchers reported in “Nature” at the beginning of the year that it is the largest genome to have been decoded for a terrestrial organism.

shouldn’t regeneration work for us? In decoding the axolotl’s genome, we hope to have made a small step toward answering this question, as the sequence of the base pairs harbors the information for the salamander’s extreme regenerative capacity.

“At our disposal we now have a genetic map which we can use to probe how complex structures such as legs can be regrown,” explained Sergej Nowoshilow,

“Cannibalism could be a key reason for an axolotl’s extreme regenerative capacity.”

This work relies on the development of a new sequencing technology (PacBio method), which is able to read some further 72 million longer portions of the genome. Individual pieces of the sequence were recombined like a jigsaw puzzle. Analyzing the data revealed some of the axolotl’s peculiarities. For instance, they lack an important and prevalent developmental gene called PAX3; the function of which has been taken up by the related gene PAX7.

Both genes play a key role in building muscles and nerves.

Genetic map with full details Humans have stem cells theoretically capable of regenerating many organs, like liver, fat and muscle stem cells. But in the course of evolution, mammals have almost completely lost this ability. If axolotls can easily regrow new limbs and organs, why

IMP postdoc and the study’s lead author. But even with this knowledge, we are still a long way from solving the puzzle, as only complex interaction between many control centers in the body enables organs to regenerate. It will be the job of young scientists such as Nowoshilow to find the right switches and understand their interaction. Because we are currently seeing such substantial progress, he can imagine that we will be far enough along in “20 or 30 years” to be able to regrow limbs.

The axolotl, to which we owe so much, is unfortunately facing a difficult future in the volcanic lakes of Mexico. The animal is on the United Nations’ red list of endangered species. Estimates from the year 2009 indicate there are only 700 to 1200 of these animals left in the wild - far fewer than those in research laboratories.

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BACKGROUND.

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GEISTLICH PHARMA AG | OSTEOLOGY FOUNDATION

A “Treatment Concepts” portfolio exactly like no other Turgut Gülay | Geistlich Pharma AG

The new brochure “Treatment Concepts: Sinus Floor Elevation” is available. It completes the portfolio of seven treatment concept brochures.

agement, major bone augmentation, minor bone augmentation, peri-implantitis, periodontal treatment, sinus floor elevation and soft tissue regeneration.

Geistlich’s “Treatment Concepts” series combines scientific evidence and everyday clinical practice. Clinical experts present their own treatment approaches in detail and summarize key factors for success – a wealth of expert knowledge! In the latest “Sinus Floor Elevation” edition, for example, Asst. Prof. Stephen Wallace, USA, shares his successful lateral sinus floor elevation using Geistlich ­Bio-Oss® covered with Geistlich Bio-Gide® at 13 years.

Order the new or previous brochures from your Geistlich partner.

Series of “Treatment Concepts” completed With the addition of this latest brochure, Geistlich now completes the entire portfolio of seven different treatment concept brochures, one for each therapeutic area: extraction socket man-

Complex bone augmentation?

The future is now!

Dr. Marcelo Caldero | Geistlich Pharma AG

A new animated movie shows the treatment of a three-tooth gap in the posterior mandible with the customized titanium scaffold Yxoss CBR®.

The movie provides practical flap technique, placement of the customized 3-D printed titanium scaffold on top of the ridge, primary wound closure, scaffold removal and implant placement, step-by-step. It is also possible to simultaneously pre-plan prosthesis positioning and a regenerative procedure.

Curious to know how to combine 3-D printed technology with best in class Geistlich Biomaterials? Watch the video on YouTube using this QR Code!

Winners of the Gappy Game Dr. Mireia Comellas | Geistlich Pharma AG

In the last issue of Geistlich News, we advertised: “Play the Gappy Game, register your high score and win a ticket to the International Osteology Symposium 2019 in Barcelona.” The first three winners have been determined.

“Gappy preserve the ridge” is Geistlich’s new online video game where everybody can help Gappy collect the right biomaterials for treating its extraction sockets and at the same time avoiding bacterial contamination.

Among those who registered their highscore, the top three were awarded free tickets for the next International Osteology Symposium 2019 in Barcelona. The winners are: Elias Casals, Francois Marquie and Patricia Risso. Want to win as well? Help Gappy now. Three more tickets are waiting for you.

BACKGROUND

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Osteology Barcelona 2019

Welcome to the NEXT REGENERATION Dr. Heike Fania | Osteology Foundation

The upcoming International Osteology Symposium will take place on 25–27 April 2019 in Barcelona, Spain. The well-established symposium focusing on oral regeneration therapies not only has a new location but also features new topics, new formats and new speakers – all under the new title: “The NEXT REGENERATION”.

The chairmen of Osteology Barcelona 2019 are Christoph Hämmerle, Switzerland, and Maurício Araújo, Brazil. In their welcome letter they explain: “The title NEXT REGENERATION combines the key aspects of the symposium in Barcelona: On the one hand, the next generation of regenerative therapies; on the other hand, the next generation of dentists, not only as attendees but also featuring upcoming experts in the field of oral tissue regeneration.”

The chairmen have planned specific sessions with young dentists presenting oral tissue regeneration overviews and special sessions for researchers. In addition, innovative concepts and formats, such as the Osteology Case Session, will also be part of the program, allowing more clinicians to actively participate.

“But despite all the new aspects, one thing has definitely not changed," the chairmen further explain: “In April 2019 the International Osteology Symposium is again the place to be for all oral and maxillofacial surgeons, periodontists and oral health professionals interested in implant dentistry and regenerative therapies, where internationally renowned experts will present the current state of knowledge and research and link science with practice in oral regeneration.”

A glimpse into the future, with novel techniques and materials, is waiting for you! Find the detailed information, the program, online registration and much more at www.osteology-barcelona.org.

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GEISTLICH NEWS 2-2018

New in Barcelona: Osteology Case Competition Osteology Barcelona 2019 will see the inauguration of a novel format: The Osteology Case Competition. The best oral regenerative cases in six competition categories will be selected for an oral presentation in the Osteology Case Session, and the best case will win an award.

You can submit your clinical case online at THE BOX. Only cases from the field of oral tissue regeneration uploaded to the Case Box by 31 January 2019 will be accepted for the Osteology Case Competitions.

Further information and submission: www.osteology-barcelona.org/programme/case-session/

New online education

Oral Regeneration Topic Dr. Heike Fania | Osteology Foundation

The Osteology Foundation has launched a novel online education initiative. Twice each year a new Oral Regeneration Topic is selected. Every Oral Regeneration Topic consists of a Webinar, a Scientific Radar, and Key Publication.

The aim is to provide a broad overview of different Oral Regeneration Topics, as well as to create awareness for the most important research findings, following the motto of the Osteology Foundation: Linking Science with Practice in Regeneration.

Scientific Radar A list of the most relevant literature on the current Oral Regeneration Topic will be published together with an explanation of why each selected publication is on the list.

Key Publication A key publication will be selected for each Oral Regeneration Topic and discussed through an interview with the main author.

Webinar Everyone interested in the topic is invited to submit questions in advance, and the speaker is asked to address as many questions as possible in his/her presentation. There will be a live Q & A session following the webinar, limited to 100 live participants. The whole webinar, including the discussion, will be accessible on-demand.

The novel program will be started in September 2018, and the first Oral Regeneration Topic will be “Ridge Preservation.�

For 2019 the following two topics are planned: Recession Coverage and GBR. Further information is available online at www.osteology.org/education/oral-regeneration-topic/. All Oral Regeneration Topic contents are available at THE BOX, the online platform of the Osteology Foundation. Registration for THE BOX is free!

Save the date

Upcoming Osteology events Osteology Turin, Italy (National Symposium) 27-29 September 2018

Osteology Research Academy, Beijing, China (Mandarin) 19-22 November 2018

Osteology Paris, France (National Symposium) 18-20 October 2018

Osteology @ DGI Congress Wiesbaden, Germany 1 December 2018

Osteology Research Academy Vienna, Austria 5-7 November 2018

Osteology Barcelona 2019 (International Symposium) 25-27 April 2019

Osteology @ SAP Meeting Buenos Aires, Argentina 16 November 2018 BACKGROUND

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Interview

In the phantom room with Anton Sculean Interview conducted by Dr. Giulia Cerino

You are professor and chair of the Department of Periodontology at the School of Dental Medicine, University of Berne.

How are you preparing the next generation of clinicians?

Prof. Sculean: Even in the students’ first clinical years, we get them in touch with patients. A student graduating from dental school has to be able to treat patients at a basic level and conduct routine dental procedures. In addition, teaching an evidence-based approach with a solid biological background is the key to success.

Before Bern, you studied and practiced in different locations – Budapest, Munster, Aarhus, Hamburg, Mainz and Nijmegen. Which location was your favorite?

Prof. Sculean: If I consider the beauty of the city, Budapest for sure; it is wonderful (laughs). However, in terms of learning curve, definitively Aarhus. I was mentored by professor Thorkild Karring - one of the great periodontal pioneers. Based on his work on periodontal wound healing and regeneration, the guided tissue regeneration technique for periodontal defects – still used in clinics around the world – was developed. He influenced my way of thinking.

You were among the pioneers who used Geistlich Fibro-Gide® and shared your clinical experience with the launch team. What were your first impressions?

Prof. Sculean: I was astonished by Geistlich Fibro-Gide®’s absorbency properties, especially while still maintaining its integrity. It has a kind of memory that maintains its volume.

Compared with other collagen matrices, I find Geistlich Fibro-Gide® to be an excellent biomaterial.

In March you celebrated 300 publications on PubMed. Has your research interest changed over time?

Prof. Sculean: My main interest is still the same – the biology of periodontal wound healing, including periodontal regeneration. In particular, I find the study of interactions between biomaterials and proteins/ cells very fascinating. In addition, being able to perform both preclinical and clinical studies is a great asset. But I am also interested in soft tissue regeneration, which overlaps in many ways with my main interest.

Among your research interests are lasers and photodynamic therapy in the treatment of periodontal and peri-implant infections. Where are you now with these interests?

Prof. Sculean: We already have a case series with good clinical outcomes – less bleeding, less probing depth and no tissue recession. With the proper combination of laser wavelength and mechanical debridement, we observed bio-stimulatory and antibacterial effects. In one third of the cases, the defects were resolved without surgery. I am really proud the concept was developed here in Bern!

If you had to choose 3 things that you would take to a desert island, what would they be?

Prof. Sculean (laughs): If people are not allowed, I would say a survival kit, a backpack and for sure a good book - a history or philosophy.

Prof. Anton Sculean received his PhD in periodontology at the University of Saarland, Hamburg, Germany. He has received many research awards, including the Anthony Rizzo Award for the Periodontal Research Group of the International Association for Dental Research. He is now professor and chair of the Department of Periodontology at the School of Dental Medicine, University of Bern, Switzerland, and the President of the EFP. He is on the Photo: Ines Badertscher

editorial board of more than 10 dental

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journals, and he is author and co-author of several articles in peer-reviewed journals and textbooks.

He has given more than 300 lectures at national and international meetings.

GEISTLICH NEWS 2-2018

Issue 1 | 19 will be published in April 2019.

FOCUS

Research & practice > Doing research in practice: key points > 10 research findings that impact daily practice > Photo tips for clinical case documentations SCIENCE TALK

To compress or not to compress bone substitutes?

IMPRINT

Magazine for customers and friends of Geistlich Biomaterials Issue 2/2018, Volume 13 Publisher ©2017 Geistlich Pharma AG Business Unit Biomaterials Bahnhofstr. 40 6110 Wolhusen, Switzerland Tel. +41 41 492 55 55 Fax +41 41 492 56 39 biomaterials@geistlich.ch

Editor Dr. Giulia Cerino, Verena Vermeulen Layout Larissa Achermann Publication frequency 2 × a year Circulation 25,000 copies in various languages worldwide

GEISTLICH NEWS content is created with the utmost care. The content created by third-parties, however, does not necessarily match the opinion of Geistlich Pharma AG. Geistlich Pharma AG, therefore, neither guarantees the correctness, completeness and topicality of the content provided by third parties nor liability for damages of a material or non-material nature incurred by using third-party information or using erroneous and incomplete third-party information unless there is proven culpable intent or gross negligence on the part of Geistlich Pharma AG.

BACKGROUND

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Publisher ŠGeistlich Pharma AG Business Unit Biomaterials Bahnhofstr. 40 6110 Wolhusen, Switzerland Tel. +41 41 492 55 55 Fax +41 41 492 56 39 www.geistlich-biomaterials.ch

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