Implant Practice US Fall 2020 Vol 13 No 3

clinical articles • management advice • practice profiles • technology reviews Fall 2020 – Vol 13 No 3 • implantpracticeus.com

Practice profile Josh Nagao, DDS

Essential guidelines for using CBCT in implant dentistry — clinical considerations: part 3

Treating maxillary edentulism using a screwretained prosthesis Dr. Jean-Baptiste Verdino, JeanMichel Moal, and Gilles Giordanengo

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Into the unknown: emerging evidence regarding risks of aerosols in the dental office Dr. Maria L. Geisinger

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EDITORIAL ADVISORS Steve Barter, BDS, MSurgDent RCS Anthony Bendkowski, BDS, LDS RCS, MFGDP, DipDSed, DPDS, MsurgDent Philip Bennett, BDS, LDS RCS, FICOI Stephen Byfield, BDS, MFGDP, FICD Sanjay Chopra, BDS Andrew Dawood, BDS, MSc, MRD RCS Professor Nikolaos Donos, DDS, MS, PhD Abid Faqir, BDS, MFDS RCS, MSc (MedSci) Koray Feran, BDS, MSC, LDS RCS, FDS RCS Philip Freiburger, BDS, MFGDP (UK) Jeffrey Ganeles, DMD, FACD Mark Hamburger, BDS, BChD Mark Haswell, BDS, MSc Gareth Jenkins, BDS, FDS RCS, MScD Stephen Jones, BDS, MSc, MGDS RCS, MRD RCS Gregori M. Kurtzman, DDS Jonathan Lack, DDS, CertPerio, FCDS Samuel Lee, DDS David Little, DDS Andrew Moore, BDS, Dip Imp Dent RCS Ara Nazarian, DDS Ken Nicholson, BDS, MSc Michael R. Norton, BDS, FDS RCS(ed) Rob Oretti, BDS, MGDS RCS Christopher Orr, BDS, BSc Fazeela Khan-Osborne, BDS, LDS RCS, BSc, MSc Jay B. Reznick, DMD, MD Nigel Saynor, BDS Malcolm Schaller, BDS Ashok Sethi, BDS, DGDP, MGDS RCS, DUI Harry Shiers, BDS, MSc, MGDS, MFDS Harris Sidelsky, BDS, LDS RCS, MSc Paul Tipton, BDS, MSc, DGDP(UK) Clive Waterman, BDS, MDc, DGDP (UK) Peter Young, BDS, PhD Brian T. Young, DDS, MS CE QUALITY ASSURANCE ADVISORY BOARD Dr. Alexandra Day, BDS, VT Julian English, BA (Hons), editorial director FMC Dr. Paul Langmaid, CBE, BDS, ex chief dental officer to the Government for Wales Dr. Ellis Paul, BDS, LDS, FFGDP (UK), FICD, editor-inchief Private Dentistry Dr. Chris Potts, BDS, DGDP (UK), business advisor and ex-head of Boots Dental, BUPA Dentalcover, Virgin Dr. Harry Shiers, BDS, MSc (implant surgery), MGDS, MFDS, Harley St referral implant surgeon

© FMC 2020. All rights reserved.

FMC is part of the specialist publishing group Springer Science+ Business Media. The publisher’s written consent must be obtained before any part of this publication may be reproducedvw in any form whatsoever, including photocopies and information retrieval systems.

While every care has been taken in the preparation of this magazine, the publisher cannot be held responsible for the accuracy of the information printed herein, or in any consequence arising from it. The views expressed herein are those of the author(s) and not necessarily the opinion of either Implant Practice or the publisher.

I

have seen it. We’ve all seen it. That little bit of graying from the titanium implant that peeks through the tissue of my anterior implants. It doesn’t happen every time, but I know that as my patient ages, that tissue will also age. And as that tissue recedes, the highly cosmetic case will become trickier and trickier to manage.

When a patient came knocking on my office door 4 years ago, specifically asking for a ceramic dental implant, her issue was the desire for a metal-free solution. I did research on the options available and decided to take on the case. The implant integrated fine, and I restored the case without issues. I furthered my learning on the topic and attended a couple of CE events from the ZERAMEX® company. Now made of “zirconia,” which Dr. Paresh Patel is zirconium dioxide (ZrO2), the ceramic implants are no longer prone to fracture, and I was surprised to learn that they are actually significantly harder than titanium. The fact is, the designs too have evolved. Designs are tapered, two-piece, screw-retained with customizable restorative options that fit most clinical situations. The surgical procedure is very familiar, and the ceramic implants utilize similar tooling and surgical kits. I am proof that experienced titanium surgeons can immediately incorporate modern ceramic implants into their practice with immediate success.

If your practice is close to a Whole Foods Market or another organic market, you likely have these patients that would appreciate the option. Patients are seeking a more “organic” and natural lifestyle. In dentistry, ceramic implants can be one tool in our arsenal to fulfill this request. I began marketing the use of ceramic implants. As I placed more and more of them, the soft tissue response stood out to me. I would see the soft tissue growing over the peek cover screw. The truth of the matter is, soft tissue has documented greater affinity for ceramic implants over titanium implants. Recent research raises valid concerns about the biological properties of titanium, especially with regards to peri-implantitis. Ceramic implants have documented reduction in plaque and bacterial attraction and are not susceptible to corrosion over time. I am finding that the soft tissue around my zirconia implants is similar to soft tissue around natural teeth.

As my patients become more educated and demanding, they not only want a tooth replacement for functionality and health, but also are specifically demanding exceptional esthetics. In thin tissue type and anterior cases, we have all witnessed occasional graying and metal transparency. Since ceramic implants are white and have an improved soft tissue response, they often eliminate the need for tissue grafting. Until recently, ceramic implants were not available in a small diameter. Recently, the ZERAMEX company has released a 3.5 mm Small Diameter implant. The company is marketing it as “The Cosmetic Implant,” and they are right. This is now my go-to solution for all tight spaces with thin tissue type in the anterior.

I believe it’s about time to take a serious look at modern ceramic implants as a profitable health center for your practice. Like the rapidly growing $50 billion organic market, ceramic implants are here to stay. Ceramic implants can not only help us improve the health and cosmetics of our patients, but also serve as practice differentiators, driving profitable and loyal patients. The cutting-edge developments in modern implant dentistry are growing day by day. In fact, I would like to refer to myself as the “cutting-edge guy.” But there is a difference between cutting edge and bleeding edge. I do not want to be burned by a specific product. I feel as though ceramic dental implants are no longer in the bleeding-edge era; they are ready for prime time! By all estimates, zirconia ceramic implants will experience a rapid rise in clinical acceptance. For practitioners like myself, this means now is the perfect time to incorporate them into your practice and join the quickest growing market opportunity in dental implantology!

Paresh Patel, DDS, MD, is a graduate of the University of North Carolina at Chapel Hill School of Dentistry and the Medical College of Georgia/AAID MaxiCourse. He is a fellow of the Misch International Implant Institute and a Diplomate of the ICOI. Dr. Patel has published numerous articles in leading dental journals and has worked as a lecturer and clinical consultant on dental implants and prosthetics for several companies. He maintains private practices in Lenoir and Mooresville, North Carolina.

Disclosure: Dr. Patel was not compensated for this introduction. In the future, he will be speaking on topics involving the ZERAMEX implant.

ISSN number 2372-9058

Volume 13 Number 3

Implant practice 1

INTRODUCTION

Fall 2020 - Volume 13 Number 3

I have a new go-to material for implants in the anterior

TABLE OF CONTENTS

Practice profile Josh Nagao, DDS

8

Publisher’s perspective Thoughts of business health, optimism, clarity, and prosperity Lisa Moler, Founder/CEO, MedMark Media................................6

Designer Dental with a personal touch

Continuing education Essential guidelines for using CBCT in implant dentistry — clinical considerations: part 3

Clinical 14 Into the unknown: emerging evidence regarding risks of aerosols in the dental office Dr. Maria L. Geisinger discusses likely modes of transmission for the virus that causes COVID-19

Dr. Johan Hartshorne puts the clinical protocols for appropriate application of three-dimensional imaging in implant therapy in the spotlight....................17

ON THE COVER Cover image courtesy of Dr. Jean-Baptiste Verdino, Jean-Michel Moal, and Gilles Giordanengo. Article begins on page 26.

2 Implant practice

Volume 13 Number 3

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TABLE OF CONTENTS

Technology Diagnosing and planning an implant-retained provisional bridge using a fully digital workflow — a case study Dr. Anthony Mak illustrates how digital dentistry helps him simplify clinical protocols, increase accuracy over conventional analog techniques, and improve his patient’s comfort..........33

Continuing education

26

Treating maxillary edentulism using a screw-retained prosthesis Dr. Jean-Baptiste Verdino, Jean-Michel Moal, and Gilles Giordanengo discuss the protocols for a new “tissue level” implant system to establish how it improves prosthetic rehabilitation

Service profile

Service profile

On the horizon

Next-level strategies to protect your implant practice

Silent partners are still investing in great practices

When technology plays well together

Bre Cohen discusses preparing for unexpected adverse events

Chip Fichtner offers a plan to help practices grow more profitably

..................................................36

..................................................38

Dr. Justin D. Moody discusses using compatible technologies to improve the implant experience...................40

www.implantpracticeus.com READ the latest industry news and business WATCH DocTalk Dental video interviews with KOLs LEARN through live and archived webinars RECEIVE news and event updates in your inbox by registering for our eNewsletter

CONNECT with us on social media Connect. Be Seen. Grow. Succeed. | www.medmarkmedia.com

4 Implant practice

Volume 13 Number 3

PUBLISHER’S PERSPECTIVE

Thoughts of business health, optimism, clarity, and prosperity

A

s I write this message, COVID-19 is still driving many of the operational aspects of the dental office, and dentists are trying to navigate the challenges and restrictions related to maintaining safety and health. Recently, I attended the ADA’s press conference on reopening — a meeting that gathered dental leaders to discuss CDC guidelines, dentists’ concerns, and the ADA’s direction on how to navigate with “cautious optimism” out of this crisis. Seeing these visionaries of the dental community all working to provide information and guidance to their peers empowered us at MedMark Media as well to work even harder to be an advocate for the dental community.

In these times, when it seems we are reinventing dentistry Lisa Moler Founder/Publisher, MedMark Media to accommodate new and evolving needs, we need to call upon the strengths and creativity that have navigated us out of other very difficult times in our lives and our careers. As different types of information swirl around us on the news, on social media, and in our own social circles, it is important to keep the team informed and involved in the decisions that will affect their health and safety. Keep those team meetings ongoing, so the team is aware of your consistent support. Formulate and be proactive on what steps will be taken if a team member is exposed to the virus, or if a patient with COVID-19 has entered your office.

Now is the time to use your social media to show patients your dedication to a safe environment for them and your staff. Keep them apprised of your technologies that will offer them the most comprehensive care, even after COVID-19 abates and life returns to the “new normal.”

Take a look at all of the telehealth options that are possible for the dental practice. This tool can be useful for prescreening patients as well as scheduling and check-in to reduce the amount of people at your front desk or in your waiting rooms. Make sure that you have clear instructions on your online presence as well as in the waiting area and any area that requires social distancing or face masks. And be clear on when face masks are required in your office (such as removing the mask in the operatory and putting it back on when leaving the room or in the presence of others).

In this issue, we continue to provide articles on subjects that can expand your implant practice far into the future. In part 3 of his CE, Dr. Johan Hartshorne continues his discussion of CBCT imaging — covering when to use a CBCT, analyzing and reading the data volume, and minimizing radiation-related patient risk. In their CE, Drs. Dr. Jean-Baptiste Verdino, et al., discuss a technique using a screw-retained, implant-borne prosthesis. Dr. Maria Geisinger clears the air on the topic of aerosol risks and modes of transportation of COVID-19 in the dental office. Since telemedicine is a growing and necessary part of practice life, marketer Rachael Sauceman offers safe and effective marketing solutions to keep your patients close and cared for. During COVID-19 and after, we strive to keep bringing you ideas and information for clinical and business aspects of your practice.

Wishing you and your business health, optimism, clarity, and prosperity in these everchanging moments we are all facing.

To your best success!

Lisa Moler Founder/Publisher MedMark Media

6 Implant practice

Published by

PUBLISHER Lisa Moler lmoler@medmarkmedia.com DIRECTOR OF OPERATIONS Don Gardner don@medmarkmedia.com MANAGING EDITOR Mali Schantz-Feld, MA, CDE mali@medmarkmedia.com | Tel: (727) 515-5118 ASSISTANT EDITOR Elizabeth Romanek betty@medmarkmedia.com MANAGER CLIENT SERVICES/SALES SUPPORT Adrienne Good agood@medmarkmedia.com CREATIVE DIRECTOR/PRODUCTION MANAGER Amanda Culver amanda@medmarkmedia.com MARKETING & DIGITAL STRATEGY Amzi Koury amzi@medmarkmedia.com EMEDIA COORDINATOR Michelle Britzius emedia@medmarkmedia.com SOCIAL MEDIA & PR MANAGER April Gutierrez medmarkmedia@medmarkmedia.com FRONT OFFICE ADMINISTRATOR Melissa Minnick melissa@medmarkmedia.com

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Volume 13 Number 3

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PRACTICE PROFILE

Josh Nagao, DDS Designer Dental with a personal touch

Dr. Nagao and lead dental assistant Jessica with a happy patient

What can you tell us about your background?

I earned my Doctorate of Dental Surgery from The Ohio State University, graduating first in my class clinically. After completing my graduation requirements in my third year of dental school, I spent much of my remaining time in Ohio with an oral surgeon, performing cases under his supervision. I was able to gain valuable, hands-on experience with larger, more complex surgeries and general anesthesia. That experience has had a huge influence on how I practice today.

When did you become a specialist, and why?

I am particularly passionate for dental surgery, including implant placements, sedation dentistry, and complex reconstructions.

8 Implant practice

Although I am not an oral surgeon or periodontist, I am currently working on credentialing as an Associate Fellow with the American Academy of Implant Dentistry and, as soon as I have been out of school for 7 years, will start the process of credentialing as a Diplomate with the American Board of Oral Implantology. I think credentialing is an important part of keeping up-to-date with techniques, maintaining surgical skills, and peer critique of your cases.

Is your practice limited solely to implants, or do you practice other types of dentistry?

I own a general practice that I purchased in 2016. I also travel to other practices in southern Arizona and provide surgical and IV sedation services a few days a month.

Dr. Josh Nagao Volume 13 Number 3

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PRACTICE PROFILE Additionally, at least once a month, I teach as a mentor at Implant Pathway in Tempe.

Why did you decide to focus on implant dentistry?

I love the challenging aspect of surgery in general. The differences between each patient and situation keep it exciting and mentally challenging.

Do your patients come through referrals?

As the owner of a general practice, a majority of my new patients come from referrals from my existing patient base. However, more recently, I have had other dentists in southern Arizona start referring complex implant cases, full-arch, large-grafting cases, and other complex surgeries to me.

Whether it is guided surgery, or 3D printing/milling in-house, I think those who embrace technology and use it to better their skills will be those who rise to the top.

How long have you been practicing implant dentistry, and what systems do you use?

I have been placing implants since I graduated from The Ohio State University in 2015. I have placed a variety of systems but currently place MegaGen AnyRidge® and BioHorizons® Tapered Pro Implants.

What training have you undertaken?

In the past 5 years (since graduating dental school), I’ve completed over 500 hours in implant-specific CE. This has ranged from conferences put on by implant manufacturers, online courses, single-day courses, full-arch guided courses — really anything I can get my hands on. I also maintain sedation licenses in two states, so I have yearly training necessary to maintain those credentials. I am a member of the American Dental Association, the American Academy of Implant Dentistry, the International Congress of Oral Implantologists, and the American Society of Dental Anesthesiology.

Who has inspired you?

Drs. Justin Moody, Cory Glenn, Danny Domingue, Ramsey Amin, Matthew Fien, and Naif Sinada are a few of the people I look up to for inspiration and mentorship.

I think it’s important to surround yourself with friends and colleagues who inspire you to further your skills.

What is the most satisfying aspect of your practice?

Dr. Nagao at Implant Pathway in Tempe

The feeling when patients open their eyes after IV sedation (whether surgical or restorative) and ask if we are really done is incredible. It’s amazing to be able to offer people that kind of experience at the dentist,

Designer Dental team 10 Implant practice

Volume 13 Number 3

PRACTICE PROFILE

Dr. Nagao with his wife, Lacey

Top 10 favorites especially when those patients are likely to be the ones that have high anxiety or have a history of bad experiences with dentists.

I love the personal relationship that I build with all patients and value their trust in me.

Professionally, what are you most proud of?

I think the thing I’m most proud of is that since graduation I have acquired four practices. Two of those practices were merged into my primary general practice, and the other is an office I own with a partner who is a recent graduate. It has been extremely rewarding to see him grow and to mentor him through his first year of practice ownership.

Also, I am proud to be a faculty member and mentor at Implant Pathway, which focuses entirely on the surgical placement of dental implants, and to have been selected as a Top Dentist in Tucson by my peers.

challenging. As a fee-for-service office, growth has been slower as patients get to know and trust me as a new dentist. While growth at first was potentially slower than having contracted with insurance companies, the practice has really started growing as patients talk to their friends, neighbors, and coworkers about their positive experiences.

What would you have been if you had not become a dentist?

is treating patients like gold. If you don’t have your patients’ trust and respect, you have nothing.

I think I still would have gone into medicine, probably anesthesiology or plastic surgery.

What advice would you give to a budding implant dentist?

What do you think is unique about your practice?

What is the future of implants and dentistry?

The experience that our patients get at our practice sets us apart from others. As a fully fee-for-service practice, our patients are choosing us because of how we make them feel and the quality we provide, not because we are on their insurance list.

The integration of technology is absolutely the future of implants and dentistry.

Whether it is guided surgery, or 3D printing/ milling in-house, I think those who embrace technology and use it to better their skills will be those who rise to the top.

What has been your biggest challenge?

What are your top tips for maintaining a successful specialty practice?

I think the thing that is unique about my practice is also what has been the most Volume 13 Number 3

1. Carestream CS 3600 and CS 8100 combination 2. Osstell ISQ 3. SprintRay Pro Printer 4. Blue Sky Plan® 5. Acteon Piezotome® Cube 6. BIOLASE Waterlase dental laser 7. MegaGen Fully Guided Surgical Kit (keyless) 8. Frings® Forceps 9. PRF/PRP Centrifuge (Drucker Diagnostics) 10. GE B40 Patient Monitor

I think the key to maintaining any practice

Never stop learning. Take CE that is interesting but that also increases your ability to serve your patients’ needs at a higher level.

When you learn, make sure you implement those new skills immediately into practice.

What are your hobbies, and what do you do in your spare time?

Most of my free time is spent with my wife, Lacey, and our three kids, but she will tell you I always have a project going on. I’m currently rebuilding a restomod 1970 Datsun 240Z, and I love to play around with my 3D printers. IP Implant practice 11

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CLINICAL

Into the unknown: emerging evidence regarding risks of aerosols in the dental office Dr. Maria L. Geisinger discusses likely modes of transmission for the virus that causes COVID-19

A

erosols created during dental procedures have been suggested as a risk for disease transmission for patients and practitioners in the dental office. The current worldwide pandemic of COVID-19 caused by the transmission of SARS-CoV-2 represents a novel disease and presents unique challenges for our profession moving forward. As we continue to assess transmission rates and modalities, we continue to learn about the risks posed by the airborne transmission of this virus and the risks for dental healthcare professionals and patients. Risk mitigation efforts have been suggested, but such measures should be reasonable and informed by scientific evidence and the known understanding of likely modes of transmission and subsequent infectivity.

The CDC has stated that the modes of SARS-CoV-2 transmission are most likely to be via airborne droplets and close, prolonged contact with infectious persons. Furthermore, while the infectivity of asymptomatic carriers is questionable, presymptomatic individuals have been demonstrated to be capable of viral spread. The risk of spread of infection by aerosolized particles may be affected by the type of aerosol generated, aerosol kinetics, pathogen bioload in the aerosol source, and

Maria L. Geisinger, DDS, MS, is a Professor and Director of Advanced Education in Periodontology in the Department of Periodontology at the University of Alabama at Birmingham (UAB) School of Dentistry. Dr. Geisinger received her BS in Biology from Duke University, her DDS from Columbia University School of Dental Medicine, and her MS and Certificate in Periodontology and Implantology from The University of Texas Health Science Center at San Antonio. Dr. Geisinger is a Diplomate of the American Board of Periodontology. She has served as the President of the American Academy of Periodontology Foundation and on multiple nationally and regionally organized dentistry committees. She currently serves as Chair of the ADA’s Council on Scientific Affairs and is a member of the AAP’s Board of Trustees. She has authored over 45 peer-reviewed publications. Her research interests include periodontal and systemic disease interaction, implant dentistry in the periodontally compromised dentition, and novel treatment strategies for oral soft and hard tissue growth.

Dr. Geisinger lectures nationally and internationally on topics in periodontology and oral healthcare.

14 Implant practice

Visible threshold 30-40μm Aerosol threshold 50μm Fine aerosol (may remain suspended in air) 5μm Particles may penetrate the lower respiratory tract 1μm Average bacterial size 0.2μm

Human hair 70-100μm

Figure 1: Droplet particulate size comparisons

the type of pathogen. Practically, within the dental office, it is important for dental practitioners to be familiar with the following: • Risks associated with differing modes of transmission, including droplets, aerosols, and fomite surfaces • Types of aerosols generated by common dental procedures • The nature, quantity, and sources of microbial load in such aerosols • The efficacy of current and emerging practices in mitigating aerosol-generated microbial load

Splatter and aerosols: physical and microbial properties It is well established that airborne infections may be transmitted via droplets, including splatter and aerosols.1 Splatter droplets are defined as those with particle sizes ≥50μm, generally act as a projectile, and are only airborne briefly prior to hitting a surface or falling to earth with gravitational forces. They are spread by close contact (typically within 1 meter) with the host. The particle size of aerosols is <50μm. They may remain airborne for prolonged periods of time, carry viable pathogens, and are capable of being deposited on distant surfaces. It

has been demonstrated that droplets >5μm generally remain in the upper respiratory tract while droplets ≤5μm can be inhaled into the lower respiratory tract and those ≤1μm can enter alveoli2,3 (Figure 1).

The interaction and kinetics of droplets in aerosols and splatter are complex.

In general, aerosols are always produced in conjunction with splatter, and aerosol droplets may collide with each other, causing them to coalesce and altering their size and physical properties.4 Additionally, larger droplet particles may break down into smaller particles, which may influence the microbial load and particle size.

Droplets, including splatter and aerosols, are routinely generated during physiologic activities such as breathing, talking, coughing, and sneezing. The microbial load created from these activities also differ based upon the type of microorganisms, the infectious course of each disease, and mitigation strategies such as patients wearing surgical masks.5-11 Given these findings, it can be assumed that there is signficant heterogeneity in the amount, types, and infectivity of droplets produced by individuals in vivo.

The oral cavity contains an extremely diverse microbiome and generally contains Volume 13 Number 3

Aerosols in the dental office It is well established that many dental procedures produce splatter and aerosols.

The highest amounts of aerosols produced during dental procedures are derived from the use of powered scalers, high-speed handpieces, and/or laser use.

Powered scaler use Sonic, ultrasonic, or piezoelectric devices all produce high levels of aerosol, and the amounts and distance traveled of these droplets is comparable among these devices.16-19 Aerosols produced by ultrasonic instrumentation have been detected as far away as 2 to 11 meters from the treatment site, which could extend throughout dental operatories or offices.20,21 In clinical settings, the levels of aerosols return to preoperative levels within 30 minutes to 2 hours.22,23 High-speed handpiece use High-speed handpieces can generate droplets, including splatter and aerosols containing blood and other components.20,24-27 The microbial bioload generally correlates with the microbiota present in the tooth being treated26 and the extent of caries in individual patients.28 It has been reported

that microbial fallout from restorative procedures can extend up to 1.5 to 2 meters; however, this may be mitigated by the type of evacuation used, and this has not been fully reported.29 Laser instrumentation Class IV lasers used in dentistry to excise tissue do so through vaporization.

This process generates gaseous material often referred to as a smoke plume, which is composed of 95% water.30 The remaining 5% has been reported to contain blood, particulate, and microbial matter. The particle size generated by lasers ranges from 0.1-2Îźm.30 Although there is no evidence available on disease transmission associated with lasers used in dental operatories, Escherichia coli, Staphylococcus aureus, human papillomavirus, human immunodeficiency virus, and hepatitis B virus have been detected in medical laser plumes.30 Clinical implications While much focus has been placed on the theoretical risk of disease transmission from dental aerosols, there is limited data identifying the source and infective potential of pathogens in such aerosols. Microbes such as Staphylococcus aureus, beta hemolytic Streptococci, Escherichia coli, spore-forming bacteria, fungi belonging to the genera Cladosporium and Penicillium, and Micrococcus have been identified in dental aerosols.21,31-33 As such, these findings may indicate that microbial sources potentially include saliva, dental water reservoirs including dental unit water lines (DUWL), or respiratory droplets, with the majority of cultivatable organisms

derived from non-patient sources. Water coolant used in conjunction with rotary handpieces and powered scalers has a typical flow rate of 10 to 40 mL per minute34 generally five- to 10-fold greater than unstimulated and stimulated saliva; it can be theorized that significant dilution of salivary or respiratory pathogens occurs in these settings. Because it is expected that SARS-CoV-2 and other airborne pathogens are likely transmitted via human secretions, this dilution may prove to reduce the overall pathogenic bioload and, therefore, infectivity of such aerosols (Table 1).

Bioaerosol mitigation in the dental office Although there is no evidence implicating dental procedures in the spread of viral particles, the recent COVID-19 epidemic has created an increased awareness of airborne disease transmission and has increased interest in the potential to mitigate aerosol exposure for dental healthcare providers and patients. Strategies to achieve this may include the following: 1. Better identifying potentially infectious individuals 2. Reducing aerosol bioload 3. Barriers that reduce droplet deposition and aspiration for dental healthcare providers 4. Reduction of aerosol droplets in room air.19 Strategies to achieve this may include screening prospective patients for common disease symptoms and/or testing prior to invasive procedures, implementing pre-procedural mouth rinses, use of advanced respiratory protections during

Table 1: Aerosol-generating procedures in dentistry and perioperative mitigation strategies Aerosol-generating risk associated with procedures

Dental devices/procedures

Airborne contamination potential

Potential mitigation for droplet/aerosols

High

Powered Scalers

Considered to be the greatest source of aerosol contamination in dental practice

High-volume during powered scaler use reduces airborne contamination by > 95%

High-Speed Handpiece use without Rubber Dam Barrier

High-aerosol production

Rubber dam use and high-volume evacuation during high-speed use can significantly reduce aerosol production

Air Polishing

Airborne bacterial counts indicate aerosol production nearly as high as with ultrasonic scalers

High-volume evacuation during powered scaler use reduces airborne contamination by > 95%

Air-water Syringe

Airborne bacterial counts indicate aerosol production nearly as high as with ultrasonic scalers

High-volume evacuation during powered scaler use reduces airborne contamination by > 99%

Tooth preparation with High-Speed Handpiece and Rubber Dam Placement

Reduced airborne contamination if proper placement of a rubber dam is in place

High-volume evacuation is indicated

Tooth preparation with Air Abrasion

Microbial contamination is unknown. Extensive contamination with abrasive particles has been shown

Use of a rubber dam and high-volume evacuation is indicated

Moderate

Low

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a high number of microorganisms. Exogenous infections within or originating from the oral cavity may be influenced by the exposure to and pathogenicity of the infectious organism as well as host susceptibility.

Host factors that may influence infectivity include age, immune-inflammatory status, smoking status, and/or concomitant microbial infections.12-15

CLINICAL aerosol-generating procedures, utilization of high-volume evacuation during procedures known to generate dental aerosols, and implementation of advanced technologies to “scrub” the air, including air filtration and/ or ultraviolet light decontamination.19,27,35-40

Gaps in our current understanding The dental profession continues to have unanswered questions about aerosol production in the dental office and its ability to infect dental practitioners, staff, and subsequent patients. Information regarding the bioload of aerosols produced in clinical dental settings and the necessary infective doses of various airborne pathogens are critical to our understanding of risks.

Additional research focusing on factors that influence aerosol spread in dental offices, such as airflow and mitigation strategies, is critical. Lastly, epidemiologic evidence of the prevalence of infections in dental healthcare providers and a comparison to populations as a whole may shine a light on highly protective infection control practices that can be implemented to keep practitioners and patients as safe as possible.

Conclusion In summary, available evidence suggests the following: 1. Aerosols are generated by all individuals during many routine activities, including speaking, eating, and breathing.

2. The bioload in aerosols correlates with disease severity for respiratory diseases.

3. Aerosols are also created during most dental procedures. The dental procedures associated with the highest levels of aerosols are powered scalers, high-speed handpieces, air-water syringes, and air polishers.

4. Most current evidence suggests that dental water reservoirs are the primary source of pathogens in these aerosols, rather than saliva or respiratory secretions.

5. Several methods are effective in mitigating the production of dental aerosols and in reducing bioload. Chief among these are the use of highvolume evacuators and pre-procedural mouth rinsing, but effectiveness may vary based upon implementation within dental practices.

6. Similarly, several barrier techniques are effective in protecting the 16 Implant practice

occupants of the dental operatory from direct and indirect aerosol exposure. These include commonly used PPE such as surgical masks/respirators, face shields, fluid impermeable gowns, and gloves.

7. No evidence exists to suggest that dental healthcare professionals are at a higher risk of airborne viral disease transmission than the general population, and emerging evidence suggests that the risk may be lower during the delivery of dental care than in other healthcare settings.

8. Nonclinical areas within the dental office and/or community exposure of dental personnel may pose a significant risk within the dental office, and adherence to public health guidelines is critical to limit spread of airborne illness. IP

REFERENCES 1. Keene CH. Airborne Contagion and Air Hygiene. William Firth Wells. J Sch Health. 1955;25:249-249.

2. Annex C—Respiratory Droplets. In: Atkinson J, Chartier Y, Pessoa-Silva CL, et al., eds. Infection Control in HealthCare Settings. WHO Press, World Health Organization.

Geneva, Switzerland; 2009. https://www.who.int/water_ sanitation_health/publications/natural_ventilation.pdf.

Accessed July 6, 2020.

3. Micik RE, Miller RL, Mazzarella MA, Ryge G. Studies on dental aerobiology, I: bacterial aerosols generated during dental procedures. J Dent Res. 1969;48(1):49-56.

4. Hinds WC. Aerosol Technology: Properties, Behavior, and Measurement of Airborne Particles. 2nd ed. Hoboken, NJ: John Wiley & Sons (Wiley-Interscience); 1999.

5. Zheng Y, Chen H, Yao M, Li X. Bacterial pathogens were detected from human exhaled breath using a novel protocol. J Aerosol Sci. 2018;117:224-234.

6. Knibbs LD, Johnson GR, Kidd TJ, et al. Viability of Pseudomonas aeruginosa in cough aerosols generated by persons with cystic fibrosis. Thorax. 2014;69(8):740-745.

7. Hatagishi E, Okamoto M, Ohmiya S, et al. Establishment and clinical applications of a portable system for capturing influenza viruses released through coughing. PLoS One. 2014;9(8):e103560.

8. Yan J, Grantham M, Pantelic J, et al. Infectious virus in exhaled breath of symptomatic seasonal influenza cases from a college community. Proc Natl Acad Sci USA. 2018;115(5):1081-1086.

9. Tang JW, et al. Absence of detectable influenza RNA transmitted via aerosol during various human respiratory activities — experiments from Singapore and Hong Kong. PLoS One. 2014;9;e107338. doi:10.1371/journal.pone.0107338 10. Milton DK, Fabian MP, Cowling BJ, Grantham ML, McDevitt JJ. Influenza virus aerosols in human exhaled breath: particle size, culturability, and effect of surgical masks.

PLoS Pathog. 2013;9(3).

11. Wood ME, Stockwell RE, Johnson GR, et al. Face Masks and Cough Etiquette Reduce the Cough Aerosol Concentration of Pseudomonas aeruginosa in People with Cystic Fibrosis. Am J Respir Crit Care Med. 2018;197(3):348-355.

12. To KKW, Yip CCY, Lai CYW, et al. Saliva as a diagnostic specimen for testing respiratory virus by a point-of-care molecular assay: a diagnostic validity study. Clin Microbiol Infect. 2019;25(3):372-378.

13. Kim YG, Yun SG, Kim MY, et al. Comparison Between Saliva and Nasopharyngeal Swab Specimens for Detection of Respiratory Viruses by Multiplex Reverse TranscriptionPCR. J Clin Microbiol. 2017;55:226-233.

14. Tada A, Shiiba M, Yokoe H, Hanada, Tanzawa H. Relationship between oral motor dysfunction and oral bacteria in bedridden elderly. Oral Surg Oral Med Oral Pathol Oral

Radiol Endod. 2004;98(2):184-188.

15. Tada A, Hanada N, Tanzawa, H. The relation between tube feeding and Pseudomonas aeruginosa detection in the oral cavity. J Gerontol A Biol Sci Med Sci. 2002;57(10):M71-M72.

16. Gross KB, Overman, PR, Cobb C, Brockmann S. Aerosol generation by two ultrasonic scalers and one sonic scaler.

A comparative study. J Dent Hyg. 1992;66(7):314-318.

17. Rivera-Hidalgo F, Barnes JB, Harrel SK. Aerosol and splatter production by focused spray and standard ultrasonic inserts. J Periodontol. 1999;70(5):473-477.

18. Graetz C, Plaumann A, Jule Bielfeldt J, et al. Efficacy versus health risks: An in vitro evaluation of power-driven scalers.

J Indian Soc Periodontol. 2015;19(1):18-24.

19. Harrel SK, Barnes JB, Rivera-Hidalgo F. Aerosol and splatter contamination from the operative site during ultrasonic scaling. J Am Dent Assoc. 1998;129(9):1241-1249.

20. Grenier D. Quantitative analysis of bacterial aerosols in two different dental clinic environments. Appl Environ Microbiol.

1995;61(8):3165-3168.

21. Singh A, Shiva Manjunath RG, Singla D, et al. Aerosol, a health hazard during ultrasonic scaling: A clinico-microbiological study. Indian J Dent Res. 2016;27(2):160-162.

22. Dutil S, Meriaux A, de Latremoille M-C, et al. Measurement of airborne bacteria and endotoxin generated during dental cleaning. J Occup Environ Hyg. 2009;6(2):121-130.

23. Veena HR, Mahantesha S, Joseph PA, Patil SR, Patil SH. Dissemination of aerosol and splatter during ultrasonic scaling: a pilot study. J Infect Public Health.

2015;8(3):260-265.

24. Bennett AM, Fulford MR, Walker JT, et al. Microbial aerosols in general dental practice. Br Dent J. 2000;189(12):664-667.

25. Osorio R, Toledano M, Liébana J, Rosales JI, Lozano JA. Environmental microbial contamination. Pilot study in a dental surgery. Int Dent J. 1995;45(6):352-357.

26. Bentley CD, Burkhart NW, Crawford JJ. Evaluating spatter and aerosol contamination during dental procedures. J Am Dent Assoc. 1994;125(5):579-584.

27. Yamada H, Ishihama K, Yasuda K, et al. Aerial dispersal of blood-contaminated aerosols during dental procedures.

Quintessence Int. 2011;42(5);399-405.

28. Serban D, Banu A, Serban C. Tuta-Sas I, Vlaicu B. Predictors of quantitative microbiological analysis of spatter and aerosolization during scaling. Rev Med Chir Soc Med Nat Iasi. 2013;117:503-508.

29. Rautemaa R, Nordberg A, Wuolijoki-Saaristo K, Meurman JH. Bacterial aerosols in dental practice — a potential hospital infection problem? J Hosp Infect. 2006;64(1):76-81.

30. Bargman H. Laser-generated Airborne Contaminants. J Clin Aesthet Dermatol. 2011;4(2):56-57.

31. Hallier C, Williams DW, Potts AJC, Lewis MAO. A pilot study of bioaerosol reduction using an air cleaning system during dental procedures. Br Dent J. 2010;209(8):E14, 32. Teanpaisan R, Taeporamaysamai M, Rattanachone P, Poldoung N, Srisintorn S. The usefulness of the modified extra-oral vacuum aspirator (EOVA) from household vacuum cleaner in reducing bacteria in dental aerosols.

Int Dent J. 2001;51(6):413-416.

33. Kobza J, Pastuszka JS, Bragoszewska E. Do exposures to aerosols pose a risk to dental professionals? Occup Med (Lond). 2018;68(7):454-458.

34. Lea SC, Landini G, Walmsley AD. Thermal imaging of ultrasonic scaler tips during tooth instrumentation. J Clin Periodontol. 2004;31(5):370-375.

35. Jacks ME. A laboratory comparison of evacuation devices on aerosol reduction. J Dent Hyg. 2002;76(3):202-206.

36. Yadav N, Agrawal B, Maheshwari C. Role of high-efficiency particulate arrestor filters in control of air borne infections in dental clinics. SRM J Res Dent Sci. 2015;6:240-242.

37. American Society for Healthcare Engineering. ASHE™ website. Air filtration. https://www.ashe.org/compliance/ ec_02_05_01/01/airfiltration. Accessed July 5, 2020.

38. Chen C, Zhao B, Cui W, et al. The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient’s mouth in the indoor environment of dental clinics. J R Soc Interface. 2010;7(48):1105-1118.

39. Alexander DD, Bailey WH, Perez V, Mitchell ME, Su S. Air ions and respiratory function outcomes: a comprehensive review. J Negat Results Biomed. 2013;12:14.

40. Lindblad M, Tano E, Lindahl C, Huss F. Ultraviolet-C decontamination of a hospital room: Amount of UV light needed.

Burns. 2020;46(4)842-849.

Volume 13 Number 3

Dr. Johan Hartshorne puts the clinical protocols for appropriate application of three-dimensional imaging in implant therapy in the spotlight Introduction This article is the third in a series that aims to provide clinicians with an overview of the scientific literature relating to the use of cone beam computed tomography (CBCT). It will suggest clinical guidelines for selecting an appropriate radiographic imaging modality, indications for using CBCT, and how to read and analyze CBCT data volume. It will also address the clinical application and use of CBCT, and the advantages and limitations of CBCT in implant dentistry.

The knowledge gained and guidelines provided by this article aim to enhance clinicians’ understanding of when to use a CBCT, and how to systematically analyze and read the data volume to maximize the diagnostic and treatment planning benefits of this technology, while optimizing patient safety and minimizing radiation-related patient risk. Radiographic images used were obtained from a Kodak Carestream CS 9300 CBCT unit.

Application of CBCT imaging in implant dentistry Successful and predictable implant dentistry requires accurate preoperative diagnostics and treatment planning information of the amount of bone available, bone density, and the proximity to anatomical structures. Healthcare providers are also obligated to acquire adequate information from patients to provide a basis for informed patient consent (Miles and Danforth, 2014).

Clinical complexity, regional anatomic considerations, potential risk of complications, and esthetic considerations in the location of implants are factors that determine the individual clinician’s needs for information supplemental to that already obtained from the clinical and radiographic examinations (periapical and panoramic) to formulate a diagnosis and to assist in implant therapy treatment planning (Bornstein, et al., 2014).

Educational aims and objectives

This clinical article aims to provide clinicians with an overview of the scientific literature relating to the use of cone beam computed tomography.

Expected outcomes

Implant Practice US subscribers can answer the CE questions on page 32 or take the quiz online at implantpracticeus.com to earn 2 hours of CE from reading this article.

Correctly answering the questions will demonstrate the reader can: •

Identify when to use a CBCT and how to systematically analyze and read the data volume in order to maximize the diagnostic and treatment planning benefits of this technology.

•

Identify certain imaging goals to support preoperative diagnostics and treatment planning.

•

Realize how CBCT can offer information regarding quantitative bone availability and ridge morphology.

•

Observe how CBCT can help the clinician identify physiological, biological, and pathological considerations.

•

Recognize how clinicians can increase therapeutic opportunities by computer-assisted prosthetic and surgical treatment planning in conjunction with CBCT data.

•

Realize how CBCT images can aid in postoperative assessment of failures and complications.

The introduction and widespread use of CBCT over the last decade has enabled clinicians to diagnose and evaluate the jaws in three dimensions, thus replacing CT as the standard of care for implant dentistry (Bornstein, et al., 2014). Additionally, multiplanar imaging-reformatting (MPR) of CBCT has significantly increased diagnostic accuracy and efficiency (Jacobs and Quirynen, 2014; Deeb, et al., 2017) and offers an unparalleled diagnostic approach when dealing with previously challenging unknown anatomical boundaries and/or pathological entities (Angelopoulos, 2014).

This has prompted several different organizations to develop clinical guidelines and recommendations for the appropriate use of CBCT for assessing potential dental implant sites. Examples follow: • American Academy of Oral and Maxillofacial Radiology (AAOMR) • European Academy of Osseointegration (EAO) • International Congress of Oral Implantologists (ICOI)

Johan Hartshorne, BSc, BChD, MChD, MPA, PhD(Stell), FFPH RCP(UK), is a general dental practitioner at Intercare Medical and Dental Centre, Tyger Valley, South Africa.

Volume 13 Number 3

• Academy for Osseointegration (AO) • International Team for Implantology (ITI) CBCT has applications in several aspects of dentistry. To appropriately use this technology, clinicians should be able to identify those situations when CBCT is likely to provide useful information, and when this additional information translates into enhanced diagnoses, treatment plans, and treatment outcomes (Mallya, 2015).

The application or use of CBCT in implant dentistry includes preoperative diagnostics and treatment planning, computer-assisted treatment planning, and postoperative evaluation — focusing on implant failures and complications due to damage of neurovascular structures (Jacobs and Quirynen, 2014; Bornstein, et al., 2014).

Preoperative diagnostics and treatment planning Radiographic assessment of the 3D implant position, angulation, and restorative space is essential during preoperative diagnostics and treatment planning of implant sites within the residual alveolar bone.

Positioning of single implants within the dental arch can be challenging, considering the proximity to adjacent tooth roots, vital Implant practice 17

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Essential guidelines for using CBCT in implant dentistry — clinical considerations: part 3

CONTINUING EDUCATION structures, occlusal plane, and relative position within the arch (Scherer, 2014).

CBCT imaging therefore must provide information supportive of the following goals: 1. To establish the quantitative bone availability (morphologic characteristics) of the residual alveolar ridge.

2. To determine the orientation of the residual alveolar ridge.

3. To identify local anatomic or pathologic boundaries within the residual alveolar ridge limiting implant placement (Bornstein, et al., 2014).

Quantitative bone availability Effective preoperative assessment requires clinicians to interpret implant sites for many factors related to predictable and successful implant restorations, including adequate bone volumes, distance away from teeth/implants, sufficient prosthetic space for restoration, and precise implant placement.

Essential preoperative assessment should include an evaluation of the saddle length (mesiodistal), vertical bone height (occlusalapical), and horizontal width (buccolingual) bone availability of the proposed implant recipient site (Figure 1) to facilitate proper planning, correct implant selection, 3D placement of the dental implant (Figure 2), and the necessity for implant site development (Tyndall, et al., 2012; Scherer, 2014).

Most CBCT viewing and analysis software packages feature measurement tools that can be used to easily determine the height and width of bone and the proximity of the proposed implant placement site to adjacent vital structures. With this software, the clinician can accurately visualize the 3D alveolar ridge bone contour of a patient and make determinations about surgical entry, implant diameter and length, and prosthetic requirements before the surgical procedure.

CBCT also provides a qualitative assessment of the type of bone (bone quality) and

local trabecular architecture (Figures 3 and 4) to assist in selecting the correct implant type to optimize implant stability. The standard practice is to visually analyze trabecular density and sparseness at the edentulous site.

Some studies have explored the feasibility of measuring CBCT gray values at the edentulous area to infer bone quality (Mah, et al., 2010; Valiyaparambil, et al., 2012).

However, there is strong evidence that the relationship between gray value and object density is markedly influenced by

several factors, including exposure parameters, FOV, and anatomic location (Oliveira, et al., 2013, 2014; Parsa, et al., 2013; Pauwels, et al., 2013). Current gray value approaches to quantitatively assess bone quality are thus unreliable.

CBCT is an essential tool for identifying the extent and size of bone defects at potential implant sites that may require augmentation or site development to prepare it for simultaneous or later implant placement (Harris, et al., 2012). Examples of

Figure 1: Activating “nerve canal tool” icon to plot the inferior alveolar nerve and “measurement mode” icon for measuring the implant osteotomy site. Typical implant treatment planning measurements are saddle length (mesiodistal) (upper right), residual alveolar bone width (buccolingual), and vertical length (occlusal-apical) (lower right)

Figure 2: Virtual implant placement in the correct 3D position

Figure 3A-3C: Qualitative preoperative assessment of alveolar bone and trabecular architecture in the maxilla. 3A. Type 2 bone. 3B. Type 3 bone. 3C. Type 4 bone

Figures 4A-4D: Qualitative preoperative assessment of alveolar bone density and trabecular architecture in the mandible. 4A. Type 1 bone. 4B. Type 2 bone. 4C. Type 3 bone. 4D. Type 4 bone 18 Implant practice

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Ridge morphology The buccolingual ridge pattern cannot be viewed on 2D radiographs, but CBCT provides the advantage of showing the type of alveolar ridge pattern present. Crosssectional images (coronal view) provide the implant dentist with the appearance of ridge patterns such as irregular ridges, narrow crestal ridges, and knife-shaped ridges (Figures 12 and 13).

The loss of cortical plates and undulating concavities (Figure 14) can also be appreciated on cross-sectional images, and they cannot be seen on panoramic images. In the case of a compromised jaw bone (in terms of quality and/or quantity of bone), the panoramic technique is an inefficient imaging tool. Three-dimensional imaging is often indispensable when treatment planning to identify potential risks.

Bone quality is a matter of not only content, but also structure. It has been shown that the quality and quantity of bone available at the implant site are very important local patient factors in determining potential

Figure 5: Horizontal bone volume deficiency requiring augmentation

Figures 7A-7B: 7A. 3D rendering of a dehiscence defect (denuded areas extend through marginal bone) requiring horizontal buccal bone augmentation. 7B. 3D rendering of a dehiscence defect (denuded areas extend through marginal bone) requiring horizontal buccal bone augmentation

Figures 8 and 9: 8. Axial view of a post-extraction site at 8 weeks (5x5 FOV). 9. Vertical bone deficiency in the posterior maxilla

Figure 10: Combined horizontal and vertical alveolar ridge bone discrepancy in the posterior Volume 13 Number 3

Figure 6: Fenestration defect (marginal bone intact) requiring buccal bone augmentation

Figure 11: Vertical alveolar bone deficiencies in the posterior maxilla requiring sinus floor elevation (5x10 FOV) Implant practice 19

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procedures requiring augmentation or site development follow: • horizontal bone volume deficiencies (Figure 5) • fenestration defects (marginal bone intact) (Figure 6) • dehiscence bone defects (denuded areas extend through the marginal bone) (Figure 7) • post-extraction site (Figure 8) • vertical bone deficiency (Figure 9) • combined horizontal and vertical bone deficiencies of the alveolar ridge (Figure 10) • sinus floor elevations (Figure 11) The use of CBCT before bone block grafting helps define both the donor and recipient sites, allows for improved planning for surgical procedures, and reduces patient morbidities.

CONTINUING EDUCATION

Figures 12A-12E: 12A. Coronal view of an irregular alveolar ridge in the maxilla. 12B. Coronal view of an irregular alveolar ridge in the mandible. 12C. Coronal view of a narrow crestal alveolar ridge in the mandible. 12D. Coronal view of a narrow crestal alveolar ridge in the maxilla. 12E. Coronal view of a knife-shape crestal alveolar ridge in the mandible

implant stability and the success of dental implants. Bone quality is categorized into four groups (Figure 4; Bone Quality Index) (Lekholm and Zarb, 1985): • Type 1: homogeneous cortical bone • Type 2: thick cortical bone with marrow cavity • Type 3: thin cortical bone with dense trabecular bone of good strength • Type 4: very thin cortical bone with low-density trabecular bone of poor strength.

In the jaws, an implant placed in poor quality bone with thin cortex and low-density trabeculae (Type 4 bone) has a higher chance of failure compared with the other types of bones. This low-density bone is often found in the posterior maxilla, and several studies report higher implant failure rates in this region (Lekholm and Zarb, 1985).

Topography and orientation of residual alveolar bone The orientation and residual topography of the alveolar basal bone complex must be assessed to determine whether or not there are variations that could compromise the alignment of the implant fixture with the planned prosthetic restoration. This is particularly important in the mandible (for example, the submandibular gland fossa) (Figure 15) and anterior maxilla (for example, labial cortical bone concavity) (Figure 16).

Information on the topography and orientation of the residual alveolar bone is important to optimize implant selection and placement.

Anatomical considerations, boundaries, and limitations Each location in the dental alveolus has unique morphologic and topographical characteristics owing to edentulousness and specific regional anatomic features that need to be identified and assessed in the 20 Implant practice

Figures 13 and 14: 13. Knife-shape crestal alveolar ridge in the posterior maxilla. 14. Serial axial images of the maxilla showing undulating buccal bone concavities due to missing anterior teeth (5x10 FOV)

Figures 15 (left) and 16 (right): Coronal view of the topography and orientation of the residual alveolar bone in the submandibular gland fossa area

diagnostic and treatment-planning phase of dental implant therapy.

The clinician must have full knowledge of oral bone anatomy, boundaries, and limitations so that any osseous topography, bone volume excesses/deficiencies can be identified to facilitate optimal implant placement and to avoid surgical complications.

A comprehensive overview of the oral and maxillofacial anatomy is provided in the

literature, but for the purposes of this article, only the critical anatomical elements related to implant dentistry are presented.

Anterior maxilla The maxillary anterior region (commonly referred to as the esthetic zone) often presents both surgical and prosthetic implantassessment complexities (Dawson, et al., 2009; Buser, et al., 2007). Subsequent to Volume 13 Number 3

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tooth loss, decrease in the height and/or width of the alveolar process and the development of a labial concavity often necessitate bone augmentation to facilitate implant placement (Misch, 2008) (Figure 16).

The morphology and dimension of the nasopalatine (incisive canal) (Figure 17) and the location of the floor of the nasal fossae may also compromise bone availability for implant placement (Ganz, 2011; Mraiwa, et al., 2004; Romanos and Greenstein, 2009; Asaumi, et al., 2010).

Posterior maxilla Atrophy of the edentulous posterior alveolar ridge and pneumatization of the maxillary sinus are the most common causes of lack of bone availability for implant placement in the posterior maxilla.

Additionally, the maxillary posterior region has the lowest bone density (Figure 3) and the highest implant failure rate (Gupta, et al., 2017). Sinus floor elevation surgery, along with bone grafting, is a well-accepted technique before or simultaneously with implant placement to increase support in an atrophic maxilla.

Knowledge about the sinus anatomy and residual alveolar ridge is critical before the conduction of surgical procedures. CBCT images provide an accurate 3D representation of the anatomy and are suitable for the detection of morphologic variations in the maxillary sinus to assist with preoperative assessment for sinus augmentation surgery, implant planning, and placement (DaneshSani, et al., 2017; Shanbhag, et al., 2014).

The available residual alveolar ridge in the posterior maxillary premolar and molar regions is limited superiorly by the floor of the maxillary sinus (Figure 11).

Anatomical variations of the maxillary sinuses â&#x20AC;&#x201D; such as the presence of septa (also known as Underwood septa), number, location, and shape, particularly in the inferior sinus wall â&#x20AC;&#x201D; complicate sinus floor elevation surgical procedures (Mallya, 2015).

Sinus septa are bony projections commonly found in the inferior or lateral sinus walls separating the maxillary sinus into two or more compartments (Figure 18). Studies show approximately 45% of patients had at least one septum (Sakhdari, et al., 2016).

Strong sinus membrane adhesion at the location of septa, particularly of the inferior sinus wall, may cause perioperative complications; therefore, the presence, extent, and location of septa must be accurately detected in presurgical radiographic imaging to facilitate proper selection of the surgical technique and prevention of unwanted perioperative Volume 13 Number 3

Figures 17A-17D: 17A. Axial view of morphology of the nasopalatine canal (incisive canal) in the anterior maxilla (5x10 FOV).

17B. Coronal view of morphology of the nasopalatine canal (incisive canal) in the anterior maxilla (5x10 FOV). 17C. Serial axial views of the nasopalatine canal. 17D. Serial coronal views of implant placement planning in relation to the nasopalatine canal in the anterior maxilla

Figure 18: Sinus septa in the inferior sinus wall

complications and thus increase success rate of sinus surgeries (Park, et al., 2011; Sakhdari, et al., 2016). Medium-sized or long septa may necessitate a modified surgical approach. Detection of septa may also influence the decision about the location of the window in the lateral window approach during sinus floor elevation surgery.

Assessment of the anterior recess of the maxillary sinus is also important if markedly angled implants are considered for implantsupported edentulous prostheses. CBCT can also provide information on arterial channels in the lateral wall of the sinus, presence of apical pathology (Figure 19) as well as on the health of the sinus such as absence of sinus membrane thickening (Figure 20).

In some clinical situations, when there is evidence of sinus pathology, or it is the clinicianâ&#x20AC;&#x2122;s opinion that sinus drainage is

Figure 19 : Apical pathosis in the posterior maxilla

impaired and may jeopardize the outcome of the procedure to be undertaken, there may be a justification to extend the FOV to include the whole of the sinus, including the osteomeatal complex (Ribeiro-Rotta, et al., 2011; Janner, et al., 2011; Carmeli, et al., 2011).

Implant practice 21

CONTINUING EDUCATION Anterior mandible The anterior mandible is a relatively safe location for implant placement. However, proper diagnostics are essential to avoid intraoperative and postoperative hemorrhage, neurosensory loss, and risk of perforating the cortical plate. The locations of osseous structures (buccal and lingual cortical plates) (Figure 22) and neurovascular structures include the lingual foramen (Figure 22), the terminal branch of the inferior alveolar nerve at the mental foramen, and the anterior loop (Figures 21 and 23).

The mental foramen is a strategically important landmark during osteotomy procedures in the mandible. Its location and the possibility that an anterior loop of the mental nerve may be present mesial to the mental foramen need to be considered before implant surgery to avoid nerve injury (Greenstein and Tarnow, 2006).

Posterior mandible In the posterior mandible, there are several anatomic structures that can compromise prosthetically driven, dental implant placement. The most important landmarks in the posterior mandible are the inferior alveolar canal and the submandibular gland fossa (Figures 24 to 26). Both these structures can present with anatomic variations that may restrict implant placement and result in complications.

Correct identification of the inferior alveolar (mandibular) canal may help the clinician to avoid damaging the nerve during surgery and, thereby, prevent the occurrence of complications, such as impaired sensory function and paresthesia of the lower lip and the neighboring soft tissues (Abarca, et al., 2006).

It is advisable to measure from the crest of the alveolar bone to the coronal aspect of the IAN and subtract 2 mm to provide a safety zone. The submandibular fossa is denoted by a lingual concavity or undercut

in the posterior mandible and contains the submandibular gland.

Physiological, biological, and pathological considerations Other local anatomic boundaries and limitations or pathologic conditions that could potentially restrict implant placement and cause complications include:

• Inadequate distance between neighboring teeth • Angulation of roots • Apical pathology on neighboring teeth (Figures 19 and 27) • Impacted teeth (Figures 27 and 28) • Residual roots • Presence of foreign material (Figure 29)

Figure 20: Implant planning in the posterior maxilla and sinus membrane thickening

Figure 21: Mental foramen and anterior loop and terminal branch of the inferior alveolar nerve

Figure 22: Buccal and lingual cortical plates in the anterior mandible and lingual foramen

Figure 23: Serial coronal cross sections of mental foramen in the anterior mandible

Figures 24-26: 24. Inferior alveolar canal and submandibular gland fossa in the posterior mandible. 25. Inferior alveolar canal and mental foramen showing the anterior loop of the mental nerve. 26. Implant planning in the posterior mandible showing implants in relation to the inferior alveolar canal and the submandibular gland fossa 22 Implant practice

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Apart from the diagnostic capabilities, dental CBCT may also offer therapeutic capabilities through computer-assisted surgical and prosthetic treatment planning via computer-aided design/computeraided manufacturing solutions (Jacobs and Quirynen, 2014; Harris, et al., 2012). Bornstein, et al. (2014), propose some guidelines for treatment planning. CBCT DICOM data is merged with stereolithography (STL) files from an intraoral optical scanner to produce a 3D rendering (3D conversion) model of the jaw for virtual planning.

Virtual planning software is used to construct a virtual wax-up and to place the implant fixture in its correct three-dimensional position on the virtual 3D model. Information to be gathered from the combination of highquality CBCT images and STL files should include locations of vital structures, desired implant positions and dimensions, the need for augmentation therapy, and the planned prostheses. Once the design is completed, it is submitted to a milling machine or a digital printer for fabrication of a surgical guide. The guide can be bone, tooth, or mucosal supported.

The actual surgical guide is milled or printed, all with round cylinders, allowing dedicated instrumentation (drill bits) to be precisely guided, creating osteotomies and guiding the implant in its correct or ideal 3D position during placement. Implants placed using computer-guided surgery with a follow-up period of at least 12 months demonstrate a mean survival rate of 97.3% (n = 1,941), which is comparable to implants placed following conventional procedures (Bornstein, et al., 2014).

To improve image data transfer, clinicians should request radiographic devices and third-party dental implant software applications that offer fully compliant DICOM data export.

It is important to realize errors can occur when transferring information from a crosssectional computer image to the surgical situation. The surgeon should be aware of these and be careful to allow an adequate safety margin in all cases (Harris, et al., 2012). The use of guided surgery for implant placement is increasing because of a number of clinical advantages, including increased practitioner confidence and reduced operating time.

Postoperative assessment of failures and complications Altered sensation and possible damage to neurovascular structures CBCT may offer surgical guidance and therapeutic possibilities and cases of altered sensation and possible damage to neuro-vascular structures. Current evidence (Juodzbalys, et al., 2013) supports the protocol that a CBCT be used following the neurosensory assessment to pinpoint lesion location as well as confirmation of IAN injury. Proper preoperative planning, timely diagnosis, and treatment are key factors in avoiding and managing neurovascular complications and damage after implant placement (Figure 29).

Infection or postoperative integration failure CBCT is indicated for implant failure cases, infection, or postoperative integration

Figure 27: Apical pathosis on impacted premolars

failure, owing to either biological or mechanical causes. A CBCT can provide therapeutic assistance with characterizing the existing defect, plan for surgical removal and corrective procedures, such as ridge preservation or bone augmentation, and assess what the implications of surgical intervention is on adjacent structures.

Cross-sectional imaging, optimally CBCT, should also be considered if implant retrieval is anticipated (Tyndall, et al., 2012).

Implant displacement The use of CBCT scans are helpful in postoperative evaluation of implant displacement into the sinus or nasal cavity (Figure 30) (Chappuis, et al., 2009).

Perforations The major potential risks of encountering a lingual plate perforation (Figure 31) are massive hemorrhage of the submental and sublingual arteries (anterior mandible) (Kalpidis and Setayesh, 2004) and airway obstruction (Givol, et al., 2000). Perforation of the lingual concavity above the mylohyoid ridge might injure the lingual nerve (Chan, et al., 2010). If the extruded implant is left unattended, the infection might spread to the parapharyngeal and retropharyngeal space, leading to more severe complications, such as mediastinitis, mycotic aneurysm

Figure 28: Axial view of impacted premolars in relation to the osteotomy sites

Figures 29A-29B: 29A. Foreign body located in the osteotomy site. 29B. Using CBCT for neurosensory assessment and confirmation of inferior alveolar nerve injury (with permission from Dr. Howard Gluckman) Volume 13 Number 3

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Computer-assisted prosthetic and surgical treatment planning

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Figures 30-32: 30. Using CBCT for postoperative assessment of complications such as implant placement into the nasal cavity (with permission from Dr. Howard Gluckman). 31. Implant perforating the lingual cortical plate (with permission from Dr. Howard Gluckman). 32. Streaking artifact from dental implant

formation with possible subsequent rupture of the internal carotid artery, and internal jugular vein thrombosis with septic pulmonary embolism or upper airway obstruction (Greenstein, et al., 2008).

Advantages of CBCT in implant dentistry Here are several major benefits of CBCT scans for dental implant planning and placement (Klokkevold, 2015).

Precision placement of implants in the bone CBCT allows the surgeon to accurately measure and localize the available bone and accurately place the implant in a correct 3D position. This is verified by virtual implant placement.

Proper orientation of the implant with its overlying restoration A CBCT can be merged with an optical scan of the patient’s teeth (widely referred to as a digital impression) to create a complete digital model of the patient’s bone, teeth, and soft tissues. This will facilitate precise positioning of implants to support planned restorations. This prevents misaligned implants, which may be difficult or impossible to restore, and avoids poor esthetics and function.

Prevention of injury to nerves Using the CBCT, the surgeon should map out the path of the sensory nerves in the jawbone and selects an implant of the correct length. Conventional X-rays are flat and distorted and are poor diagnostic images for predicting the position of the nerves. Nerve damage from dental implant placement results in partial or complete numbness of the lip and chin area, which can be potentially permanent. CBCT is a mandatory imaging technique to prevent this serious complication.

Prevent implant penetration into the sinus CBCT provides an accurate picture of the 24 Implant practice

maxillary sinus and its position in relation to the available bone. The surgeon can make an accurate measurement and select the right implant length to avoid puncturing the maxillary sinus. Penetration of the maxillary sinus can lead to sinusitis or other inflammatory conditions. The surgeon can also plan for necessary bone grafting if there is insufficient bone to support the implant. Conventional X-rays are highly inaccurate for these purposes and do not provide the information necessary for the safe placement of dental implants in the posterior maxilla.

Selection of the right size implant for optimal support The longevity and success of dental implants require maximal integration and stability in the bone. CBCT allows the surgeon to measure the available bone and to select the widest and longest implant appropriate for the site. This, in turn, helps support the high bite (occlusal) forces and avoid potential failure from overload. Implant size selection should not be guesswork. Implant selection is made based on precise measurements, biological requirements, bite scheme, and individual patient needs.

Improved clinical outcomes and reduced risk of complications CBCT offers a more accurate, predictable outcome and safer means to dental implant placement. CBCT should be mandatory diagnostic imaging for every implant treatment. Not using CBCT for planning is unwise for the surgeon and creates unnecessary risk for the patient and clinician.

Communication of data volume CBCT allows the ability to communicate DICOM data imaging information for prosthetic restorative planning, and design and manufacturing of surgical guides.

Limitations of CBCT There are a number of limitations with CBCT clinicians should be aware of:

• Requires training and has a learning curve • Requires expertise and specialized equipment • Poor soft tissue contrast • Not an ideal tool for assessing bone density • Imaging artifacts • Radiation dose

Conclusion CBCT imaging technology computer software has significantly increased the accuracy and efficiency of diagnostic and treatment capabilities, thereby offering an unparalleled diagnostic approach when dealing with previously challenging unknown anatomical and/or pathological entities in implant dentistry.

The potential benefits for accurate assessment, diagnosis of pathologies, identification of anatomical landmarks and neurovascular structures, as well as topographical and morphological deviations in alveolar bone, in preoperative treatment planning are undisputed.

CBCT has become the new professional standard of care as imaging modality for diagnosis and preoperative treatment planning in implant dentistry. The decision to prescribe a CBCT scan must be based on the patient’s history and clinical examination — justified on an individual basis due to consideration of diagnostic and preoperative treatment planning needs and benefits, radiation risk, and cost.

Effective assessment of proposed implant sites requires that clinicians interpret implant sites for many factors related to successful implant restorations, including adequate bone volumes, distance away from teeth/implants, sufficient prosthetic space for restoration, and precise implant placement.

This article proposes a protocol for performing a structured review and reading CBCT data volume to ensure pathology or critical anatomical structures are not missed that may impact on or enhance diagnosis, Volume 13 Number 3

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12. Buser D, Belser UC, Wismeijer D (eds). Implant therapy in the esthetic zone: single-tooth replacements. Berlin, Germany: Quintessence Publishing; 2007.

13. Carmeli G, Artzi Z, Kozlovsky A, Segev Y, Landsberg R. Antral computerized tomography pre-operative evaluation: relationship between mucosal thickening and maxillary sinus function. Clin Oral Implants Res. 2011;22(1):78-82.

14. Carter L, Farman AG, Geist J, et al. American Academy of Oral and Maxillofacial Radiology executive opinion statement on performing and interpreting diagnostic cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2008;106(4):561-562.

15. Chan HL, Leong DJ, Fu JH, et al. The significance of the lingual nerve during periodontal/implant surgery. J Periodontol. 2010;81(3):372-337.

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45. Mraiwa N, Jacobs R, Van Cleynenbreugel J, et al. The nasopalatine canal revisited using 2D and 3D CT imaging.

Dentomaxillofac Radiol. 2004;33(6):96-402.

46. Oliveira ML, Tosoni GM, Lindsey DH, et al. Influence of anatomical location on CT numbers in cone beam computed tomography. Oral Surg Oral Med Oral Pathol Oral Radiol.

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26. Greenstein G, Tarnow D. The mental foramen and nerve: Clinical and anatomical factors related to dental implant placement: A literature review. J Periodontol.

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6. AO (Academy of Osseointegration). 2010 Guidelines of the Academy of Osseointegration for the provision of dental implants and associated patient care. Int J Oral Maxillofac Implants. 2010; 25(3):620-627.

44. Misch CE. Contemporary implant dentistry. 3rd ed. St. Louis, MO: Mosby Elsevier; 2008.

21. Farman AG. Guest editorial — Self-referral: an ethical concern with respect to multidimensional imaging in dentistry? J Appl Oral Sci. 2009;17(5):i.

3. Adibi S, Zhang W, Servos T, O’Neill PN. Cone beam computed tomography in Dentistry: What dental educators and learners should know. J Dent Educ. 2012;76(11): 1437-1442.

5. Angelopoulos C. Anatomy of the Maxillofacial Region in the Three Planes of Section. Dent Clin N Am. 2014;58(3) :497-521.

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43. Miles DA, Danforth RA. Reporting Findings in the Cone Beam Computed Tomography Volume. Dent Clin N Am. 2014;58(3):687-709.

50. Parks ET. Cone beam computed tomography for the nasal cavity and paranasal sinuses. Dent Clin N Amer.

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51. Parsa A, Ibrahim N, Hassan B, et al (2013) Influence of cone beam CT scanning parameters on grey value measurements at an implant site. Dentomaxillofac Radiol. 42(3): 79884780.

52. Patel S, Durack C, Abella F, et al. European Society of Endodontology position statement: The use of CBCT in endodontics. Int Endod J. 2014;47(6):502-504.

53. Pauwels R, Nackaerts O, Bellaiche N, et al. Variability of dental cone beam CT grey values for density estimations.

Br J Radiol. 2013;86(1021):20120135.

28. Grey EB, Harcourt D, O’Sullivan D, Buchanan H, Kilpatrick NM. A qualitative study of patients’ motivations and expectations for dental implants. Br Dent J. 2013;214(1):E1.

54. Pauwels R, Jacobs R, Singer SR, Mupparapu M. CBCTbased bone quality assessment: Are Hounsfield Units applicable? Dentomaxillofac Radiol. 2015; 44(1):20150238.

29. Gupta A, Rathee S, Agarwal J, Pachar RB. Measurement of Crestal Cortical Bone Thickness at Implant Site: A Cone Beam Computed Tomography Study. J Contemp Dent Pract.

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55. Ribeiro-Rotta RF, Lindh C, Pereira AC, Rohlin M. Ambiguity in bone tissue characteristics as presented in studies on dental implant planning and placement: a systematic review.

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31. Harris D, Horner K, Grondahl K, et al. EAO guidelines for the use of diagnostic imaging in implant dentistry 2011. A consensus workshop organized by the European Association for Osseointegration at the Medical University of Warsaw. Clin Oral Implants Res. 2012;23(11):1243-1253.

57. Sakhdari S, Panjnoush M, Eyvazlou A, Niktash A. Determination of the Prevalence, Height, and Location of the Maxillary Sinus Septa Using Cone Beam Computed Tomography.

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32. Jacobs R, Quirynen M. Dental cone beam computed tomography: justification for use in planning oral implant placement. Periodontology 2000. 2014;66(1):203-213.

33. Janner SF, Caversaccio MD, Dubach P, et al. Characteristics and dimensions of the Schneiderian membrane: a radiographic analysis using cone beam computed tomography in patients referred for dental implant surgery in the posterior maxilla. Clin Oral Implants Res. 2011;22(12):1446-1453.

34. Juodzbalys G, Wang HL, Sabalys G, Sidlauskas A, GalindoMoreno P. Inferior alveolar nerve injury associated with implant surgery. Clin Oral Impl Res. 2013;24(2):183-190.

58. Sato S, Arai Y, Shinoda K, Ito K. Clinical application of a new cone-beam computerized tomography system to assess multiple two-dimensional images for the preoperative treatment planning of maxillary implants: case reports. Quintessence Int. 2004;35(7):525-528.

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2012;113:817-826.

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treatment planning and treatment outcomes.

CBCT is increasingly being accepted as the new professional standard of care in implant dentistry. With this technology, adequately trained clinicians can enhance their practice and best serve the interests of their patients.

However, with growing technological and software development and increasing use of this indispensable technology, it is important that the dental profession develops evidence-based guidelines and recommendations for its proper and effective use. IP

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Treating maxillary edentulism using a screwretained prosthesis Dr. Jean-Baptiste Verdino, Jean-Michel Moal, and Gilles Giordanengo discuss the protocols for a new “tissue level” implant system to establish how it improves prosthetic rehabilitation Introduction Treating complete maxillary edentulism with a screw-retained implant-borne prosthesis followed by immediate functional loading has become a standard treatment (Esposito, et al., 2013). The number and position of the implants can vary depending on the school and the physician; the All-on-4 technique (Malo, 2005), for example, is now reasonably accepted as a therapeutic option.

This technique uses four implants to support the future denture: Ideally, two are positioned at the lateral incisor, and the two posterior implants are positioned at the second premolar, angled so that they follow the anterior sinus wall (Szmukler-Moncler, 1998). Because of this, angulated abutments of 17° or 30° are generally used to correct the axis and have an emergence compatible with the future prosthesis (Rangert, et al., 2006).

This clinical case aims to present the use of a new kind of implant, which features tissue level positioning (meaning that the implant emerges at the gingival level, as opposed to the level of the bone), a flat connecting element, and a prosthetic locking system.

Educational aims and objectives

This clinical article aims to present the protocols for applying the Axiom® TL implant and InLink® connection in All-on-4 treatment.

Expected outcomes

Implant Practice US subscribers can answer the CE questions on page 32 or take the quiz online at implantpracticeus.com to earn 2 hours of CE from reading this article.

Correctly answering the questions will demonstrate the reader can: •

Identify the surgical, technical, and restorative protocols for achieving success in this indication.

•

Recognize the Axiom TL system and its parts.

•

Observe a clinical case in which the Axiom TL system was used.

•

Realize certain postoperative clinical controls.

•

Observe the final bridge development phase of this process for this specific patient.

Figure 2: The InLink connection

The Axiom® TL (Tissue Level) system Axiom® TL implants (Anthogyr) are designed with a variable transgingival height (1.5 mm, 2.5 mm, and 3.5 mm) that ends in a flat connecting element. They are constructed from Grade 5 titanium with two styles of threading available (PX or REG), depending on bone density (Figure 1).

Below the threading, the implant narrows at the neck (Anthogyr’s “tissue favored design”), which is intended to promote epithelial connective attachment and primary healing (Hermann, et al., 2001; Atieh, et al.,

Dr. Jean-Baptiste Verdino is doctor of dental surgery, earned a DEA in surgical sciences, and is teaching fellow at the DU of Implantology of Aix-Marseille II. Jean-Michel Moal is a dental prosthetist.

Gilles Giordanengo is a dental prosthetist.

26 Implant practice

Figure 1: Axiom TL (Tissue Level) implants. Note the constriction at the neck

2010; Bolle, et al., 2015). This shape is designed to result in better protection for the underlying bone and better resistance to peri-implantitis. The system also provides transgingival abutments called InLink® (Figure 2), which transform a bone level implant into a tissue level implant. The transgingival part comes in two diameters (4 mm and 4.8 mm).

The InLink connecting element allows for the creation of multiple-unit screw-retained prostheses. A locking system is integrated into the prosthesis, composed of a fastening lock and a retention ring (Figure 3). The flat connection can make positioning the

prosthesis a delicate procedure, so a guiding system is available.

The retention ring is found in the cervical portion of the prosthesis within a specifically machined housing (Figures 4 and 5).

The InLink connection allows significant divergences from the implant axis to be corrected without the addition of intermediate abutments, as well as the integration of angulated screw channels up to 25° with narrowed screw channels. Because the connection is integrated into the prosthesis, there is no manipulation of the screw; the prosthetic is locked with a ball wrench (Figure 6).

Creating a temporary prosthesis on InLink is easy because the temporary abutments come in both straight and angulated versions (25°) (Figures 7 and 8), which remove the decision about angulated abutments during surgery and delegate that choice to the laboratory. These can be delivered with fitting locks (green) for testing in the prosthesis in the mouth.

Volume 13 Number 3

Figure 4: The lock in situ in the bridge

Figure 5: Transparent view of the bridge and the different elements, including locks and InLink connections

Figure 6: The spherical screw wrench

The green locks should be replaced with clinical locks (titanium in color) when the prosthesis is placed. Changing locks is simple with the dedicated instrument (Figure 9).

Moreover, a laboratory clip is also included, which is designed to be screwed onto the replicas and avoids tedious screwing and unscrewing (Figure 10).

Clinical case This case follows a 62-year-old female to demonstrate the clinical and restorative protocols for treatment using Axiom implants and the InLink connection. This patient presented with no significant medical history, complete maxillary edentulism, and partial mandibular edentulism (Figures 11 to 14).

The mandible was planned for treatment first with a fixed cement-retained prosthesis.

Because of the lack of bone in the area under the sinuses, an All-on-4 maxillary restoration was indicated with two implants under the nasal cavities and two angulated implants along the anterior sinus walls (bone in areas I and II, according to the Bedrossian classification) (Bedrossian, et al., 2008), followed by immediate loading.

The angulation of the distal implant offers several advantages: • Places the implant between the anterior sinus wall and the palatal cortical bone.

• Using a longer implant naturally presents a larger surface for boneimplant contact, which gives sufficient primary stability and is therefore compatible with the immediate loading technique.

• Moves the emergence of the implant distally, thereby reducing the future cantilever (Aparicio, et al., 2010).

Immediate loading was planned to follow the surgery.

Preparing for immediate loading After mandibular restoration, the patient models were mounted in the articulator, and Volume 13 Number 3

Figures 7 and 8: Straight and angulated abutments

Figure 9: InLink assembly and disassembly tool

Figure 11: Preoperative panoramic radiograph

Figure 10: Laboratory lock

Figure 12: Preoperative CBCT

Figure 14: The completely edentulous maxilla

Figure 13: Clinical CBCT

esthetic testing was done, tested, and validated. Mounting in the articulator is a vital step to create a coherent occlusal plan.

A silicone key of this arrangement was produced, which was used to produce a radiological and surgical transparent resin guide, and a full arch with stock teeth ready to be joined to the future abutments.

The chosen teeth were filled with resin (VITAPAN® PLUS, Vita North America; Yorba Linda, California) to facilitate adjustment by drilling, and also because of wear and tear from the opposing teeth. The surgical guide was then perforated at the palate in the placement envelope for future implants.

This had two goals: • To guide surgery when the implants are positioned.

• To serve in the occlusion transfer following surgery.

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Figure 3: The lock and retaining ring

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Figure 15: The anterior sinus wall was marked

Figure 16: Placement of the distal implant

Figure 18: A tissue punch was used to adjust the gingiva

Figure 19: The surgical guide was rebased with Jet Blue Bite to register the occlusion

Surgical phase

Drilling was carried out progressively with graduated drill bits increasing in diameter until the final drilling at 3 mm. Implants with a diameter of 3.5 mm were used here to preserve the maximum peri-implant bone, particularly toward the vestibular. This choice was supplemented by that of the transgingival part — in this case, 2.5 mm in height and 4.8 mm diameter.

This part is also available in 1.5 mm and 3.5 mm heights as a function of the peri-implant mucosa thickness and also in a narrower 4 mm diameter, which is useful in the incisor/canine area in cases of low resorption.

After inserting the four implants, H4 cylindrical healing screws were placed, and the tissues sutured with 4.0 resorbable sutures (Figure 17).

Tissue adjustment is usually carried out at this stage to optimize peripheral soft tissues, encourage the best possible gingival healing, and facilitate future hygiene procedures. This has the goal of placing as much keratinized gingiva around the head of the implant as possible without burying it too far.

This operation is generally performed with a blade, but a tissue punch is often very pleasant to use (Figure 18).

The surgical guide was then filled with silicone (Jet Blue™ Bite, Coltène/Whaledent Inc.; Cuyahoga Falls, Ohio) and repositioned in place. Once the material had set,

Local anesthesia was administered at multiple bilateral injection sites: • high-tuberosity approach • suborbital • palatal A full-thickness flap was created, and four 3.4 mm R Axiom TL implants (4.8 mm diameter) height 2.5 were placed: First, the subnasal mesial implant was placed with an infracrestal placement of the 0.5 mm implant threading. To place the distal implant as close as possible to the anterior sinus wall, a window was made on the anterior part of the maxillary sinus, and the topography of the anterior sinus wall was determined using a depth gauge (Figure 15). This allowed us to create an angulated drilling hole from the distal to the mesial and from the vestibular to the palatal.

As a result, the implant was positioned close to two areas of dense bone: the anterior sinus wall and the palatal cortical bone. This allowed the distal implant to be placed as far away as possible, as well as at the maximum anteroposterior distance, depending on the case in question (Figure 16). This position allowed us to reduce the degree of cantilever (Aparicio, et al., 2010), which was essential for the final bridge. In this case, the implant emergence was located around the first premolar.

The cantilever would be definitively reduced for the provisional bridge without framework.

28 Implant practice

Figure 17: Sutures placed around the healing abutments

Figures 20A and 20B: A. A control X-ray was taken to confirm the position of the implants. B. Implants in place

the occlusion was recorded by applying Jet Blue Bite on the guide (Figure 19). The healing screws were removed, specific transfers were screwed, and their adjustment was checked radiologically (Figures 20A and 20B).

A plaster impression (Snow White™, Kerr; Brea, California) (Urstein, et al., 1991) was taken using a filmed impression-maker, specifically designed for this kind of impression (Figure 21). The use of this material is almost completely reliable in terms of the precision of the position of transfers and dimensional stability. After taking the impression, the transfers were unscrewed Volume 13 Number 3

implants. To do this, the bridge is screwed to 25Ncm on the working model, and the whole ensemble is placed in boiling water under pressure for 10 minutes, then allowed to air-cool for around 20 minutes.

Passivity is verified by unscrewing the bridge and re-screwing it onto one of the replicas, and verifying it remains flat on the others. The bridge is then fitted into the mouth by alternating screws — first manually, then to 25Ncm — and the occlusal adjustment is finalized. A panoramic radiograph should then be taken to get a reference snapshot of the bone/implant situation and to check the exact fit of the cylinders on the implants (Figures 27 and 28).

Figure 21: Plaster impression

Figure 22: Working model

Figure 23: Straight and angulated cylinders

Laboratory phase

Figures 24 and 25: 24. The cylinders are secured to the arch by adding resin. 25. Protective caps fitted over the lab locks Volume 13 Number 3

Clinical controls An initial check is made after the first week, occlusion is verified again, and the patient’s ability to brush and maintain adapted hygiene is confirmed. During the period of bone healing — a minimum of 4 months — a visit should be scheduled every 3 weeks with checkup points.

Examples follow: • Occlusion • Hygiene • Lack of pain and inflammation • Lack of muscle spasms

Final bridge development phase Following the 4-month healing phase in the absence of clinical or radiographic problems, the final bridge can start to be developed. Assuming that the esthetics and function of the provisional bridge are

Figure 26: Guiding lock (left) and conventional lock (right) Implant practice 29

CONTINUING EDUCATION

The laboratory protocols begin by processing the impression. We start by applying an insulator (Vaseline®, Unilever; Englewood Cliffs, New Jersey), followed by screwing in tissue-level analogs. A false silicone gum is then poured. This facilitates obtaining an adequate emergence profile but needs to be removable to ensure the adjustment of future cylinders.

The model is then poured in GC FUJI ROCK® (GC America; Alsip, Illinois) dental stone. After unmolding, identical healing screws to the ones used in the mouth are placed in the replicas, and the surgical guide is repositioned on the model (taking care to avoid any interference with the plaster).

The model can then be remounted on an articulator.

This is followed by screwing laboratory locks onto the replicas. These have an O-ring and, as the design phases progress on the model, allow the bridge to be placed and removed without having to do tedious screwing and unscrewing (Figure 22). The laboratory technician can then choose the appropriate provisional cylinders — straight and angulated — for emergence from the screw channel on the occlusal face of the future bridge. Contrary to the conventional rule, it is no longer the abutments that are chosen to be angulated during surgery, but instead the cylinders (Figure 23).

During the laboratory phase, the InLink fastening locks are removed, and the bridge can be positioned on the model with a simple clip. It is important to note the cylinders will be silanized (with a silicoater) and covered to the point of opacity. This not only eliminates any risk of the metal being visible, but also encourages a chemical bond (beyond the mechanical bond) between the resin and the cylinders and increases the solidity of the future temporary bridge.

The prepared cylinders can then be positioned and oriented, and their height reduced as necessary. The provisional dental arch, prepared previously, is adjusted around the cylinders with successive drilling, then joined to the cylinders with self-curing resin (Figure 24). The soft tissue is adjusted with the addition of dentin or pink-colored resin, as necessary. The finishing touches to the periphery are then applied. To avoid damaging the cylinder platforms, protective caps are clipped over the laboratory locks (Figure 25).

During this stage, toothbrushes are used in the form of mini-tunnels to adjust parts of each cylinder.

The bridge is repositioned on the model for the last occlusal adjustments. Then the technician replaces the clinical locks, taking care to include a guiding lock to facilitate clinical placement of the bridge. The guiding lock is longer along the screw and makes positioning the guide easier (Figure 26). Up to two can be used on the implants with minimal relative divergence.

The bridge should then be made passive, to minimize possible harmful forces on the

and the validity of the impression confirmed by the complete immobility of the transfers in the plaster.

CONTINUING EDUCATION

Figure 27: Control radiograph

Figure 28: Immediate loading

Figure 29: Validation of the working model

Figure 30: Resin occlusal registration strip

Figure 31: The final framework was designed digitally

Figure 32: Repositioning the key on the titanium frame

Figure 33: Polymerization finished, ready for trimming

Figure 34: Trying the bridge in place

Figure 35: Confirming access for hygiene

approved, they are reproduced in terms of the vertical dimension of occlusion, the shape and color of the teeth, and especially the external profile of the bridge, such that it allows for optimal hygiene.

In All-on-4 cases with significant levels of tissue resorption, the authors’ preference is for composite bridges with a titanium framework, stock-microfilled composite teeth (VITA PHYSIODENS®, Vita North America; Yorba Linda, California), and false gum made of resin.

The framework is created with CAD/CAM as a guarantee of solidity, reliability, passivity, and as a result, the ideal biological tolerance (Miyazaki, et al., 2009; Lops, et al., 2015). A new impression is then made to record the morphology of the healed soft tissue and the position of the implants. This impression uses the open impression technique, with pickup transfers. The chosen recording material is plaster because of its precision and significant dimensional stability.

It is processed rigorously under a microscope: New replicas are screwed on with the goal of guaranteeing the compliance and traceability of the future machined framework.

Two components are created: • A plaster mold (Snow White), designed to validate the working model. If it can be screwed into without breaking, it can be considered to be passive, and the model is trusted (Figure 29).

• A resin mold, designed to record the occlusal relationship (Figure 30).

Each of these components is constructed on the temporary cylinders with adjusted diameters, either straight or angulated, as necessary. These are tested in the mouth. In the event that the plaster mold breaks, the impression is taken again.

The occlusion is recorded in wax (Moyco wax), and the models are mounted on a semiadaptable articulator. Esthetic testing then follows, which is tested clinically; it should have the exact characteristics of the future bridge and the points to check are rigorous: • Phonetic tests • VDO • Access to hygiene (use of a toothbrush) • Occlusion • Esthetics

The latter aspect in particular must be approved by the patient. After confirming these points, the bridge returns to the laboratory, and the framework design is created in software with an exterior envelope using a scanner, and according to the manufacturer’s protocol (Anthogyr) (Figure 31).

When the framework is received, the passivity of the framework and the scanned volume should be checked before moving to the finishing stages. The use of a primer (Bredent Silano-Pen procedure) is crucial to ensure that the titanium and the acrylic components bond chemically. Retaining clips are placed, just as during the creation of the temporary bridge in order to reposition the framework on the master model before pouring the resin for the tooth positioning key (Figure 32).

After curing (Figure 33), some touchups (filing, shaving, adding resin as necessary) may be performed. The occlusion is adjusted on the articulator, and the bridge is carefully polished. Before delivery, the clinical locks are put into place, two non-guiding and two guiding — critical for easy clinical placement. Without this, and because of the

30 Implant practice

Volume 13 Number 3

Final bridge delivery After the temporary bridge is removed (which can be given to the patient on the working model in the event that a future touchup is necessary), the implant heads are cleaned with chlorhexidine.

The fastening locks are coated in chlorhexidine gel (Elugel), and the bridge is positioned, then screwed into place (Figure 34): first with the guiding locks, then the other two. The first screwing on is done by hand, and a first occlusion check is done by ensuring the occlusal concepts are respected (Mariani, et al., 2008): • Anterior guiding during propulsion • Slight anterior overjet to avoid locking when centered • Protection for the lateral group • Lack of balancing contacts • Balance between the posterior areas when centered (check there is no overbite) It is critical at this stage to immediately confirm the patient’s ability to brush around the implants (Figure 35). A panoramic radiograph should be taken to ensure the exact fit of the bridge on the implants (and also to check the peri-implant bone level) (Figure 36).

Final screwing to 25Ncm can be carried out with a torque wrench, and the holes of the access channels filled with composite.

Checkups should be planned at 1 week, 3 weeks, and every 3 months for the first year. After 1 year, a new panoramic radiograph should be taken to verify bone stability and adaptation, and that nothing has come unscrewed. After that, a biannual visit is recommended.

Discussion The use of this new concept offers considerable advantages, both biological and technical.

Biological The design of these implants with tissuelevel placement improves primary healing and stability in peri-implant soft tissue (Hermann, et al., 2001; Bolle, et al., 2015). Similarly, it results in an excess of connective tissue above the crestal bone because the implant’s neck design (the aforementioned “tissuefavored design”) provides better protection for the underlying bone and a lower rate of peri-implantitis (Atieh, et al., 2010).

This design involves a learning curve in the choice of height for the transgingival part, Volume 13 Number 3

Figure 36: Final control X-ray after fitting bridge

which comes in 1.5 mm, 2.5 mm and 3.5 mm, and sometimes requires adjustment of the soft tissue — thinning them, on occasion. However, the designer planned for the InLink abutments, which are able to transform a conventional bone level implant to a tissue level, and, therefore, allows for easier management, particularly in esthetic areas.

Technical Innovation is significant here too. The flat connection allows the implants to be inclined and eliminates the tedious choice of angulated abutments, which were classically at 18° and 30°. Screwing on with the locks, guiding or not, is surprising but very easy.

The fact that these locks are on the bridge itself facilitates the positioning procedures.

Changing these locks and their removal and positioning during the laboratory phase is facilitated by a dedicated instrument.

The laboratory clips save precious time by avoiding the tedious screwing and unscrewing steps of bridge development at both temporary and final stages. The use of a ball wrench allows a part to move up to 25° from the axis of the cylinder compared to the implant. This is very useful in the case of angulated implants, but also allows for a certain freedom in positioning access channels on the occlusal face.

Conclusion This new concept is a significant improvement in the treatment of edentulism with implant-borne prostheses. Beyond a simplification of the surgical steps, particularly by eliminating the choice of abutments, it offers significant biological advances, in terms of primary healing and maintaining medium-term and long-term peri-implant health. Moreover, these technical tricks greatly facilitate the prosthetic phases. This concept also has a place in the treatment of

partial edentulism (where the ability to have angulated screws is often a major asset).

The fact the physician no longer has to interfere with the bone-implant interface during impression-taking and testing procedures guarantees security and respect for periimplant tissues. IP

REFERENCES 1. Aparicio C, Perales P, Rangert B. Tilted implants as an alternative to maxillary sinus grafting: a clinical, radiologic, and periotest study. Clin Implant Dent Relat Res. 2001;3(1):39-49.

2. Atieh MA, Ibrahim HM, Atieh AH. Platform switching for marginal bone preservation around dental implants: a systematic review and meta-analysis. J Periodontol.

2010;81(10):1350-1366.

3. Bedrossian E, Sullivan RM, Fortin Y, Malo P, Indresano T. Fixed-prosthetic implant restoration of the edentulous maxilla: a systematic pretreatment evaluation method. J Oral Maxillofac Surg. 2008;66(1):112-122.

4. Bolle C, Gustin MP, Fau D, Exbrayat P, Boivin G, Grosgogeat B. Early peri-implant tissue healing on 1-piece implants with a concave transmucosal design: a histomorphometric study in dogs. Implant Dent. 2015;24(5):598-606.

5. Esposito M, Grusovin MG, Maghaireh H, Worthington HV. Interventions for replacing missing teeth: different times for loading dental implants. Cochrane Database Syst Rev. 2013;28(3):CD003878.

6. Hermann JS, Cochran DL, Buser D, Schenk RK, Schoolfield JD. Biologic Width around one- and two-piece titanium implants. Clin Oral Implants Res. 2001;12(6):559-571.

7. Lops D, Bressan E, Parpaiola A, et al. Soft tissues stability of CAD-CAM and stock abutments in anterior regions: 2-year prospective multicentric cohort study. Clin Oral Implants Res. 2015;26(12):1436-1442.

8. Malo P, Rangert B, Nobre M. All-on-4 immediate-function concept with Brånemark System implants for completely edentulous maxillae: a 1-year retrospective clinical study.

Clin Implant Dent Relat Res. 2005; Suppl 1:S88-S94.

9. Mariani P, Margossian P, Laborde G. Choix d’un concept occlusal en implantologie. Stratégie Prothétique. 2008; 8(1):5-13.

10. Miyazaki T, Hotta Y, Kunii J, Kuriyama S, Tamaki Y. A review of dental CAD/CAM: current status and future perspectives from 20 years of experience. Dent Mater J. 2009;28(1):44-56.

11. Rangert B, Aparicio C, Malevez C, Bedrossian E, Renouard F, Malo P, Calandriello R. Graftless rehabilitation of the atrophied maxilla – tilted implants, short implants and immediate function. In: Jensen OT, (ed). The Sinus Bone Graft. 2nd ed. UK: Quintessence Publishing; 2006.

12. Szmukler-Moncler S, Salama H, Reingewirtz Y, Dubruille JH. Timing of loading and effect of micromotion on bone dental-implant interface: review of experimental literature.

J Biomed Mater Res. 1998;43(2):192-203.

13. Urstein M, Fitzig S, Moskona D, Cardash H. A clinical evaluation of materials used in registering interjaw relationships.

J Prosthet Dent. 1991;65(3):372-377.

Implant practice 31

CONTINUING EDUCATION

“flat” connection, the bridge insertion could be very difficult.

REF: IP V13.3 HARTSHORNE REF: IP V13.3 VERDINO, ET AL.

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Essential guidelines for using CBCT in implant dentistry — clinical considerations: part 3

Treating maxillary edentulism using a screw-retained prosthesis

HARTSHORNE

VERDINO, ET AL.

1.

2.

_________ and esthetic considerations in the location of implants are factors that determine the individual clinician’s needs for information supplemental to that already obtained from the clinical and radiographic examinations (periapical and panoramic) to formulate a diagnosis and to assist in implant therapy treatment planning. a. Clinical complexity b. Regional anatomic considerations c. Potential risk of complications d. All of the above The introduction and widespread use of _____ over the last decade has enabled clinicians to diagnose and evaluate the jaws in three dimensions, thus replacing CT as the standard of care for implant dentistry. a. CBCT b. 2D digital radiography c. digital panoramic images d. transillumination

3.

Additionally, _______ has significantly increased diagnostic accuracy and efficiency and offers an unparalleled diagnostic approach when dealing with previously challenging unknown anatomical boundaries and/or pathological entities. a. digital panoramic imaging b. multiplanar imaging-reformatting (MPR) of CBCT c. MRI d. transillumination

4.

The application or use of CBCT in implant dentistry includes preoperative diagnostics and treatment planning, computer-assisted treatment planning, and postoperative evaluation — focusing on _______. a. esthetic considerations b. implant failures c. complications due to damage of neurovascular structures d. both b and c

5.

_______ should include an evaluation of the saddle length (mesiodistal), vertical bone height (occlusal-apical), and horizontal width (buccolingual) bone availability of the proposed implant recipient site (Figure 1) to facilitate proper planning, correct implant selection, 3D placement of the dental implant (Figure 2), and the necessity for implant site development.

32 Implant practice

a. b. c. d.

6.

All new patient exams Essential postoperative assessment Essential preoperative assessment Optional preoperative assessment

Some studies have explored the feasibility of measuring ______ at the edentulous area to infer bone quality. a. CBCT gray values b. bacteria c. straight patterns d. microbes

7.

The buccolingual ridge pattern _______, but CBCT provides the advantage of showing the type of alveolar ridge pattern present. a. can also be viewed on 2D radiographs b. cannot be viewed on 2D radiographs c. can be viewed by visual examination d. is not imperative to implant placement

8.

Bone quality is categorized into four groups (Bone Quality Index). Type 4 bone quality is: _______ a. homogeneous cortical bone b. thick cortical bone with marrow cavity c. thin cortical bone with dense trabecular bone of good strength d. very thin cortical bone with low-density trabecular bone of poor strength

9.

In the jaws, an implant placed in poor quality bone with _______ has a higher chance of failure compared with the other types of bones. a. thin cortex and low-density trabeculae b. thin cortical bone with dense trabecular bone c. thick cortical bone with marrow cavity d. homogeneous cortical bone

10.

(To facilitate correct identification of the inferior alveolar [mandibular] canal and avoid damaging the nerve during surgery) It is advisable to measure from the crest of the alveolar bone to the coronal aspect of the IAN and _______ to provide a safety zone. a. add 2 mm b. add 4 mm c. subtract 2 mm d.

subtract 4 mm

1.

The number and position of the implants _________. a. can vary depending on the school and the physician b. will never vary c. will only be determined by using the All-on-4 technique d. will never be correct using the All-on-4 technique

2.

The framework is created with CAD/CAM as a guarantee of _______, and as a result, the ideal biological tolerance. a. solidity b. reliability c. passivity d. all of the above

3.

Final screwing to ______ can be carried out with a torque wrench, and the holes of the access channels filled with composite. a. 10Ncm b. 25Ncm c. 30Ncm d. 35Ncm

4.

5.

6.

Checkups should be planned at ______. a. 1 week, 3 weeks, and every 3 months for the first year b. 1 month, 6 months and 18 months c. 2 weeks, 6 weeks and 1 year d. every 6 weeks for the first year Similarly, it (the design of these implants) results in an excess of connective tissue above the crestal bone because the implant’s neck design (the aforementioned “tissue-favored design”) provides _______. a. the option to avoid bone grafts b. better protection for the underlying bone c. a lower rate of peri-implantitis d. both b and c This design involves a learning curve in the choice

of height for the transgingival part, which comes in ______ , and sometimes requires adjustment of the soft tissue — thinning them, on occasion. a. 1 mm, 2 mm, and 3 mm b. 1 mm, 3 mm, and 5 mm c. 1.5 mm, 2.5 mm, and 3.5 mm d. 3 mm, 4 mm, and 5 mm 7.

The designer planned for the InLink abutments, which are able to _______, and, therefore, allows for easier management, particularly in esthetic areas. a. transform a tissue level to a bone level implant b. transform a conventional bone level implant to a tissue level c. eliminate the need for a bone graft d. replicate the fit of a conventional removable denture

8.

The flat connection allows the implants to be inclined and eliminates the tedious choice of angulated abutments, which were classically at 18° and _____. a. 20° b. 25° c. 28° d. 30°

9.

The laboratory clips save precious time by avoiding the tedious screwing and unscrewing steps of bridge development at _______. a. the temporary stage only b. the final stage only c. both temporary and final stages d. none of the above

10.

The use of a ball wrench allows a part to move up to ______ from the axis of the cylinder compared to the implant. a. 5% b. 15% c. 20% d. 25°

Volume 13 Number 3

CE CREDITS

IMPLANT PRACTICE CE

Dr. Anthony Mak illustrates how digital dentistry helps him simplify clinical protocols, increase accuracy over conventional analog techniques, and improve his patient’s comfort Introduction

Advances in digital technologies are providing today’s clinicians with the tools to eliminate challenges associated with conventional analog techniques in the diagnosis, treatment planning, placement, and restoration of dental implants.

In the case that follows, Dr. Anthony Mak uses the 3Shape TRIOS® intraoral scanner, BioHorizons® Digital Library, 3Shape Implant Studio™ software, and a CBCT scan from Instrumentarium Maxio OP. His clinical case with 3Shape demonstrates the digital workflow he uses for the provision of implant-retained restorations.

The case highlights the many benefits of digital workflows. Dr. Mak provides commentary and tips throughout the case.

Digital workflow

Dr. Mak’s case illustrates key advantages of fully digital workflows: 1. A reduction in the number of patient visits for the procedure 2. A simplified and predictable workflow in implant treatment planning and guided surgery 3. Better angulation and accuracy of placement of single and multiple implants 4. A simpler and easier prosthetic design process

Dr. Anthony Mak, BDS (USyd), Grad Dip Clin Dent (Oral Implants) (USyd), is a highly skilled dental surgeon and dental practitioner, with many years of experience working in some of Sydney, Australia’s most renowned dental practices. He now brings his unique skills in the fields of dental implants, cosmetic, and restorative dentistry to his exciting new W Dental practice in Woollahra, Australia. An outstanding graduate of dentistry from the University of Sydney, Dr. Mak’s dedication to perfection and tireless effort won him numerous accolades including the W. Alan Grainger Memorial Prize and the AstraZeneca Pharmaceuticals Prize. He also won the John Stephen Hill Memorial Prize, the Dr. Henry Bruce Maxwell Prize, and the esteemed Rudolf Gunz University Medal. Dr. Mak is a current member of the Australian Dental Association, Australian Osseointegration Society, International Association of Orthodontics, and the American Academy of Cosmetic Dentistry.

Disclosure: Dr. Anthony Mak is a key opinion leader for 3Shape.

Volume 13 Number 3

Figure 1: Preoperative presentation

Figure 2: Virtual extractions for digital implant planning

Digital workflows enable professionals to combine both surface and CBCT scan data in software to virtually plan implant positions as well as design and fabricate surgical implant guides. When compared with free-hand surgery, computer-generated surgical guides significantly reduce the chances for positional errors at the time of implant placement.1 Because the implant procedure in this case is first planned in software (3Shape Implant Studio) using combined intraoral and CBCT scan data, Dr. Mak can accurately assess bone volume, bone density, and the restorative space. This, in turn, enables him to plan implant placement and identify and avoid critical anatomical landmarks, such as nerves, sinuses, and adjacent teeth, by setting up safety zones in the software.

Digital workflows also eliminate the potential for distortion of conventional impression material and inaccuracies of subsequent steps in the manufacturing process, and the potential of damage to the dental cast and treatment delay, due to logistics of sending lab work between the dental practice and the laboratory — a digital impression is simply cloud-sent, shortening the time needed to manufacture the wax-ups and prosthesis.

Digitally designed and fabricated provisional restorations can be manufactured before

or immediately post-surgical procedure for immediate temporization.

The patient’s comfort is enhanced. A digital workflow can mean less time in the chair and the elimination of patient discomfort commonly associated with the conventional impression procedure.

Case information

A patient in his early 80s presented with the chief complaint of recurrent pain, discomfort, and swelling from his lower dentition. An examination revealed moderateto-advanced bone loss of his remaining mandibular teeth. Periapical radiolucencies associated with chronic apical periodontitis were also diagnosed on the lower anterior segment. His lower dentition at the time of presentation was restored with a fixed crown and bridge prosthesis with implant fixtures on the 37 and 47 site, placed 20 years prior. The implant fixtures were abutments for fixed bridges that were linked to natural teeth abutments.

The patient requested for his lower dentition to be rehabilitated with the use of dental implants due his good perception of longevity stemming from his past treatment experience. It was the patient’s brief and request that the procedure be simple and Implant practice 33

TECHNOLOGY

Diagnosing and planning an implant-retained provisional bridge using a fully digital workflow — a case study

TECHNOLOGY

Figures 3 and 4: 3. Implant planning in 3Shape Implant Studio — four BioHorizons Tapered Internal Implants with a guide pin to maintain stability of a 3D-printed surgical guide. 4. Implant surgical guide in place after full clearance and osseous crestal reduction

Figures 5 and 6: 5. Digital mock-up of the prosthesis. The beginning of the CAD design by ceramist Bradley Grobler. You can see on this image that he was able to incorporate all the information/data on one screen, making the prosthetic design also very simple. 6. One week post-surgery

not time-consuming due to several factors.

These factors included: 1. His struggle to keep his mouth open for long periods of time 2. Difficulty in tolerating conventional impression techniques 3. His perceived age and health status

Treatment description Appointment 1 — consultation and treatment planning The patient’s failing lower dentition was heavily restored with metal ceramic crowns on the anterior segment and implant-to-teeth bridge on the posterior segment.

The teeth were virtually extracted using 3Shape Implant Studio software, leaving behind the 47 and 37 implant prosthesis.

These crowns will act as reference points — stability anchors for the implant surgical guide. By maintaining the distal abutment implant prosthesis, we will also maintain the occlusion and vertical dimension of occlusion (VDO).

Then a 3D-printed surgical guide was designed using 3Shape Implant Studio. We used the distal abutment teeth and a guide pin in the anterior mandible to create trapezoidal stability of the surgical guide in the mouth during surgery. Stability of the guide is extremely important in immediate extraction of full-arch cases.

Placing the guide pin/osteotomy in immediate extraction cases can sometimes be less accurate as the guide can rock on the soft tissue area where the extractions just took place. To avoid this, a simple 3D-guide was designed to place the guide pin/osteotomy when the teeth were still present.

Hence, once the teeth were extracted, the 34 Implant practice

implant surgical guide was easily referenced and fitted without any loss of accuracy, using the distal implant prosthesis and the anterior guide pin/osteotomy that was already placed with the first guide-pin 3D guide. This is easily achieved with 3Shape Implant Studio.

The problem with immediate extractions and guided surgery is that there are no reference points for the surgical guide to sit after the extractions. Using soft tissue and opposing occlusions is less than ideal and not as accurate as it should be. The beauty of having a guide-pin surgical guide is that we were able to place the guide pin/ osteotomy prior to extraction of the teeth.

Hence, this guide was using the hard tissue of the existing teeth prior to extractions occurring. Having the guide holes, we were able to accurately locate our second implant surgical guide once all the extractions and full clearance had occurred.

Appointment 2 — surgical appointment Immediately after surgery, BioHorizons® snap-on digital markers were placed. A 3Shape IOS scan was also performed immediately after surgery and soft tissue closure had taken place. I find this option more accurate than planning the prosthesis at the same time as implant planning. There are tolerances that may affect passive fit in multiple implant cases.

The laboratory component — Bradley Grobler Oral Dynamics Superimposing the preoperative scan for fabrication of the temporary bridge allows an exact copy of what the patient had prior to extractions. With the ability of the previous picture where we were able to scan the

Figure 7: Final image of the lower implant bridge in the patient’s mouth

occlusion, the digital workflow allows for an effortless prosthetic portion of the whole treatment process.

Bradley Grobler Oral Dynamics was directed to design and mill an immediate temporary bridge on non-engaging temporary cylinders. PMMA (Kulzer) framework was designed with pink composite and stains.

Virtual articulation in 3Shape Dental Design software ensures that there are no lateral or excursive interferences.

The wonders of digital implant dentistry!

With good planning and use of technology, we were able to achieve a direct-to-fixture prosthesis. No multi-unit abutments were required to achieve perfect prosthetic screwaccess channels.

Appointment 3 — fitting the temporary prosthesis Guided surgery allows for a much more minimally invasive approach leading to much better healing and better morbidity for the patient.

Final result Start-to-finish the case took three appointments. IP REFERENCE 1. Di Giacomo GA, Cury PR, de Araujo NS, Sendyk WR, Sendyk CL. Clinical Application of Stereolithographic Surgical Guides for Implant Placement: Preliminary Results.

J Periodontol. 2005;76(4):503-507.

Volume 13 Number 3

Return to Better Dentistry Receive up to $4,000 Rebate with a qualifying TRIOSÂŽ purchase.

Scan QR Code to redeem Terms and conditions apply. See dealer for details Š 3Shape A/S, 2020. The 3Shape name and logo and/or other trademarks mentioned herein are trademarks of 3Shape A/S, registered in US and other countries. All rights reserved.

Explore TRIOS at www.3Shape.com/TRIOS

SERVICE PROFILE

Next-level strategies to protect your implant practice Bre Cohen discusses preparing for unexpected adverse events

I

t’s safe to say COVID-19 has hit the dental industry hard. Having to close doors for months can be a big blow to any practice, and while traditional insurance is great, chances are it didn’t cover your business interruption during this pandemic.

So, how will you handle the next adverse event? That thought makes many people cringe and for good reason. However, entrepreneurial dental practices are finding ways to protect their business risks that fall outside of traditional insurance through Enterprise Risk Management programs like those from Strategic Risk Alternatives. These programs are nothing new; they’ve been utilized by Fortune 500 companies for decades. Strategic Risk Alternatives saw a need in the market to make these programs available to small-to-midsize companies and did just that. The Enterprise Risk Management program serves as a lifeline to successful companies going through a difficult time and allows them to be proactive in protecting their practice instead of reactive.

How does it work?

Much as a 401(k) helps you use taxadvantaged dollars to prepare for retirement, the Enterprise Risk Management Program by Strategic Risk Alternatives helps you use taxadvantaged dollars to prepare for unforeseen Bre Cohen is the Business Development and Marketing Manager for Strategic Risk Alternatives.

36 Implant practice

The Enterprise Risk Management program serves as a lifeline to successful companies going through a difficult time and allows them to be proactive in protecting their practice instead of reactive. risk. It utilizes U.S. Tax Code 831(b), which helps businesses set tax-deferred income aside for risks that fall outside of traditional insurance. This includes COVID-19-type disruptions as well as other cashflow disruptions. Examples follow: • contingent business interruption • political risk • supply chain interruption • key employee loss/critical illness • payroll protection Strategic Risk Alternatives serves as 831(b) plan administrators to help you identify risks, create a customized plan, manage transactions, monitor compliance, prepare paperwork, and other ongoing client services to ensure you are prepared for the next unforeseen risk.

“When COVID-19 hit, dental practices currently utilizing our program were able to recoup cash flow losses in a matter of days through their 831(b). If you own a successful dental practice, consider the advantages of setting pre-taxed dollars aside for unforeseen risks — big or small,” says Bill McKernan, President of Business Development at Strategic Risk Alternatives. “Unforeseen risk is real, and it happens every single day. It could be something as big as the next pandemic or as small as being out of work for a short period of time due to a medical issue. With our

program, you’re able to make your practice whole again and rest a little easier at night.”

Other programs for dental practices Strategic Risk Alternatives also offers a Dental Protection Plan program to help practices warranty their work. With a clearly defined warranty, you can increase patient retention and use pre-tax dollars to pay for rework.

Strategic Risk Alternatives works with practices to custom-design a defined warranty program based on their individual practice needs. Through this program, practices would set aside money from transactions and put it in their 831(b) Dental Protection Plan to fund warranties for their work. Depending on the terms the dentist sets, the warranty may require a patient to come back once a year to check the work and honor the warranty. This creates customer peace of mind, retention, and loyalty. In addition, the dentist is building a war chest to pay for any issues that do arise.

Interested in learning more? Contact Strategic Risk Alternatives by visiting their website, strategicriskalternatives.com/DPP or by calling Bill or Ed at 208-424-2249 for a free assessment and to learn more about protecting the assets that you have worked so hard to build. IP Volume 13 Number 3

MITIGATE RISK THROUGH TAX ADVANTAGED DOLLARS

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PROTECT YOUR PRACTICE WITH NE X T LEVEL STRATEGIES info@dentistprotection.com (208)424-2249 www.dentistprotection.com

SERVICE PROFILE

Silent partners are still investing in great practices Chip Fichtner offers a plan to help practices grow more profitably

I

nvisible Dental Support Organizations (IDSO) purchase part, but not all, of a practice for cash now, even during COVID19. Doctors retain ownership and continue to lead their practice under the doctor’s brand, team, and strategy for years or decades. Today, more than ever, a silent partner’s resources and support can help practices grow bigger, better, faster, and more profitably.

IDSOs are not a new concept. Some have operated for decades with IDSO ownership in thousands of practices in all 50 states.

The bedrock of the IDSO business model is that practices operated by owner-doctors perform better than those with employeedoctors. There are now well over 100 IDSOs operating in the United States with practices of all sizes and specialties. The DSOs in general are growing at a 15% rate, and it is estimated that over half of all 2021 dental school graduates will work for a DSO. The benefit to doctors of an IDSO partner include the opportunity to monetize part of their life’s work for cash now at favorable tax rates, while continuing to operate their practice for the medium- or long-term future.

When doctors are ready to retire, they have a known buyer for their retained ownership position at the value of the practice in the future. The mutual goal of doctors and their silent partner is to increase the performance and value of the practice over time using the IDSO support.

IDSO support and resources are customized for the doctor’s and the practice’s needs and goals. Every IDSO is different in its available resources.

Chip Fichtner is the founder of Large Practice Sales, which specializes in the transactions of Invisible Dental Service Organizations (IDSOs) for all practices. The company has completed more than $100 million of transactions in the past 6 months. After careers at Merrill Lynch and Bear Stearns, he began buying and selling businesses of all types for his own portfolio. Mr. Fichtner has been the Chairman and/or CEO of multiple publicly traded companies and has presented at conferences on investing and marketing from Hong Kong to Monaco. Learn more at www.findmyimplantidso.com

38 Implant practice

The goal of the IDSO is to enable doctors to focus on patient care and practice growth, not administrative minutiae.

Common IDSO support categories • Capital for acquisitions and expansion • Significant purchasing discounts, especially on implants • Professional marketing • Payor reimbursement rate leverage • Higher quality team benefits at lower costs • Potential synergies with other partner practices in the same geography • Expertise in compliance, credentialing, and HR administration/ recruiting The goal of the IDSO is to enable doctors to focus on patient care and practice growth, not administrative minutiae. Doctors are expected to lead the practice, but not necessarily manage the day-to-day activities.

Every IDSO transaction is customized for the doctor Every IDSO partnership is customized to meet the doctor’s personal and business goals. In multi-doctor practices, time commitment and purchase consideration can differ for each doctor. There are no mandates to take particular insurance payors and no requirements for longer hours or more chair time.

Doctors receive compensation for practicing based upon market rates, typically a percentage of collections, and have access to full benefits and retirement plans. Doctors who retain ownership at the practice level also receive their percentage of the practice profits, typically paid quarterly. Doctors may also choose equity in their IDSO partner, which could provide significant upside gains in value. Many doctors have made far more

from their retained equity than the initial 100% value of their practice.

Younger doctors seeking IDSO partnership Interestingly, in hundreds of millions of dollars of transactions over the past 3 years, the average age of the doctors has declined to under 50. Younger doctors are grasping the value of a strong partner to accelerate growth and thus potentially make their retained minority ownership far more valuable than their 100% ownership today.

In the COVID-19 era, many doctors are finding that growth can be achieved using their IDSO partner’s capital and management support to acquire competitive and complementary practices in their area at bargain prices.

Many doctors over the age of 60 have already secured their financial futures and have no desire to adapt to new COVID-19 era practice rules. They are also concerned about their own personal safety. These doctors are seeking a safe landing spot for their patient base. We have seen multiple transactions recently in which doctors have acquired entire practices in return for taking over lease obligations.

COVID-19 is providing opportunity The COVID-19 era has changed the operation and growth of dental practices forever. Some doctors will survive, and some will thrive. Given the potential tax increases in 2021, it is a great time to confidentially go through the free process to understand the potential value of your practice today to an IDSO partner. Many doctors are surprised. IP Volume 13 Number 3

Now is the Time To Monetize Part of Your Practice Value Invisible Dental Support Organizations (IDSO) buy 60% to 90% of your practice for cash up front. You remain as owner, operating under your brand with your team. Stay for five to 20+ years with a known exit. Silent partners provide you with the resources to grow your practice bigger, better, faster, more profitably and compete more effectively.

Recent Transactions

2X Collections, Two-Doctor General Practice, Age 30s, Sold 60%, Retained 40% 2.6X Collections, One-Doctor Periodontist and new partner will start a new office in six months.

Recent (Covid Era) Transactions

2.1X Collections, One-Doctor Oral Surgeon 2.1X Collections, One-Doctor Orthodontist 2.0X Collections, Multiple-Doctor Endodontist

DONâ&#x20AC;&#x2122;T GET CAUGHT IN THE NEXT WAVE ALONE WATCH OUR WEBINAR ON DEMAND: COVID-19 UPDATE Why IDSOs are Accelerating Partnerships With Great Doctors Earn One CE. Lecture by Chip Fichtner, Principal

19 D I V O C

To schedule a confidential call, and get a FREE practice value analysis, call 844-533-4373 or Email Implant@LargePracticeSales.com Webinar On Demand at FindMyImplantIDSO.com

ON THE HORIZON

When technology plays well together Dr. Justin D. Moody discusses using compatible technologies to improve the implant experience

O

ver the past several years, the emergence of surgical guides for the placement of dental implants has come a long way. I can remember when it was no more than making a stent off a stone model trying to get a good prosthetic outcome — today, we would call this “crazy.” Along came cone beam CT software that could help us to virtually plan cases by showing the location of bone, and we could then use a third party to put the scan of a stone model to plan this together and get a printed surgical guide.

Resourceful dentists began to cut out the middle man by buying 3D printers and starting to make their own surgical guides in-office. This has been the link to spontaneous dental work and surgical guides as now it is possible to do them same day.

Printers ran the gamut of sizes, accuracy, and price. I enjoyed early success with this as well — the workflow was a bit clunky, but we were able to provide guided surgery in a timely fashion.

Today the workflow has greatly improved, and this process is streamlined to the point where we don’t even need third-party software. Using Acteon’s latest version of AIS, we can import the surface scan into its CBCT software and design the surgical guide from the implant placement and prosthetic plan.

This is the future of surgical guide fabrication as we now go from planning to guide to surgery in one software and in one day!

Dr. Steven Vorholt has been leading the charge at Implant Pathway to create a workflow that is user-friendly and clinically accurate. Using the SprintRay Pro as our preferred 3D printer, the quality and consistency of our guides has never been better. Don’t be afraid to jump in to the

Figure 1: Importing the surface scan into the Acteon® AIS software

Figures 3 and 4: 3. Implant planning in AIS software allows for guide sleeve positioning so that the guide design can be ideal to the site and patient. 4. Surgical guide STL exported for printing; here the supports are being designed to allow for consistent printing builds

Figure 5: The SprintRay Pro 3D printer

Justin D. Moody, DDS, DABOI, DICOI, is a Diplomate in the American Board of Oral Implantology, Diplomate in the International Congress of Oral Implantologists, Honored Fellow, Fellow, and Associate Fellow in the American Academy of Implant Dentistry, and Adjunct Faculty at the University of Nebraska Medical Center. He is an internationally known speaker, founder of the New Horizon Dental Center (nonprofit clinic), and Director of Implant Education for Implant Pathway. You can reach him at justin@justinmoodydds.com.

Disclosure: Dr. Moody has no contract or financial interest in Acteon®.

40 Implant practice

Figure 2: Fully imported and aligned surface scan in AIS software ready for guide design

Figure 6: Surgical guide with authentic BioHorizons sleeves and surgical kit ready for implant placement

guided-surgery game; when used correctly, its accuracy, speed, and efficiency will save time and provide patients with the very best in dental implant treatment. IP Volume 13 Number 3

predictable, immediate results Tapered Pro Implants â&#x20AC;&#x153;The design of the Tapered Pro implants allows me to use the system for a range of treatment protocols, from single implants to complex immediate loading cases. The thread design and primary stability from the implants makes my immediate cases much more predictableâ&#x20AC;?.

Dr. Arshiya Sharafi, DDS For more information, contact BioHorizons Customer Care: 888.246.8338 or visit us online at www.biohorizons.com

#AreYouAPro Not all products are available in all countries.

SPMP19231 REV A JUL 2019

2021 CITIES

sydney Australia

learn by doing

PHILADELPHIA, PENNSYLVANIA

Presented by Drs. Bart Silverman and Adam Kimowitz

Session 2: February 5-6, 2021 Session 3: April 16-17, 2021

#implantsdoneright

Austin Alabama

Session 2: February 5-6, 2021 Session 3: March 12-13, 2021

ADDITIONAL IMPLANT COURSES Conscious Oral Sedation: September 25 - 26, 2020 G Sinus Grafting: May 26-28, 2021 Restorative Solutions: April 15-17, 2021 Full Arch Live Surgery: February 10-12, 2021

Pennsylvania

Birmingham

Presented by Dr. Justin Moody

SESSION FOUR: LIVE SURGERY October 22 - 24, 2020 December 3 - 5, 2020 March 24-26, 2021

Philadelphia Texas

OCEANSIDE, CALIFORNIA

FAST TRACK: SESSIONS 2-4 December 7-11, 2020 January 11-15, 2021 January 25-29, 2021 March 1-5, 2021 May 17-21, 2021

California

INSTRUCTOR

SCHEDULE

live patient implant education

Oceanside

Justin D. Moody, DDS Founder & Clinical Director

Dr. Justin Moody is an internationally known dentist, entrepreneur, instructor and speaker in the fields of dentistry, practice management, technology and Implantology. Dr. Moody has practices in Nebraska and South Dakota and has made a name for himself as one of the leading Continued Education providers in the United States. D Dr. Moody knows how important dental continuing education is as well as the need for mentoring and hands-on training. His conversational, real-life approach solidifies his educational philosophy.

register online at

implantpathway.com Questions? Call us at (888) 309-2423