CEREC Primemill Excellence made easy. The new CEREC Primemill is uniquely equipped for superior chairside dentistry. Our fastest milling unit ever, it’s also the easiest to use and compatible with the widest range of materials. Above all, it empowers dentists to deliver consistently excellent treatment for multiple indications. The CEREC Primemill seamlessly combines with the highly accurate CEREC Primescan and new CEREC Software 5 to redefine performance in daily practice. Join us at your local CEREC event and test it yourself. The all-new CEREC. Now is the time. Learn more at: dentsplysirona.com/cerecprimemill
CAD/CAM & Digital Dentistry Conference CAPP DENTAL CONFEXPO 1 2 - 1 4 N O V 2 0 2 0 1 2 - 1 4 N O V 2 0 2 0 D U B A I | U A E Dental Facial Cosmetic Conference 90 LECTURES | 40+ SPEAKERS | 21 CME | 13 PROGRAMMES | 3 DAYS | 100+ COMPANIES A S U , r e r e e l Sch Dr. Mi c h a reece G , a r o i s o p m a e iniK a i s s u R , h c vi A kulo A s s t . P r of.Dr. P h o t P r of.And r e y Dr.Mi l e s R D r.Albe r t o D r. Marcus E n A S U , e n o C e ed a l e u z e n e V M iselli, y n a m r e G , k al g elsch A S U , u a K H. Prof. C h u g n e c n a r F n t Sers, Dr.La u r e K U , e e Prof. A v i jit B anerj n a r I , m a d a h g o M D r. O mid M a s uf o h e c e e r G , s a e M avr D r.Dimit r i o s Prof.Sh a k e K U , r a Mill Prof. B r i a n D r.Costa N i c K U , d a d h e lSha e c e e r G , s o ul o lopo K U , n a pl n Ca y l a t I , o t a n F arro n e d e w S Urde, Dr. J u l a i Dr.Dav i d e Prof. G ö r n a a e r o K h t u o S D r. K wang B u m P ark, e c e e r G e ventis, Dr.Min a s L y l a t I , o n Gari Dr.Fra n c i s c o e c n a r F e rger, Mr. E r i c B rland e y n a m r e G H elka, M r . V a nikKauf m a n z t i w S , n a ol n-Jin n,Jordan Dr.Stef a n a d m a H d a m Ah m y n a m r e G d, n e bra D r . A h m a d Abdel S a l a D r. Detlef H i l d e c e e r G , s i t h anio n o n a b e L o ury, D r.Anto n i C s Dr.Jeﬀ K h on n a b e L , y r a k a M P r o f. C hristia n P i e rre Centre for Advanced Professional Practices (CAPP) is an ADA CERP Recognized Provider. ADA CERP is a service of the American Dental Association to assist dental professionals in identifying quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses or instructors, nor does it imply acceptance of credit hours by boards of dentistry. CAPP designates this activity for 21 CE credits CAD/CAM & Digital Dentistry Exhibition CAPP DENTAL CONFEXPO CAPP DENTAL CONFEXPO 1 2 - 1 4 N O V 2 0 2 0 D U B A I , U A E Dental Facial Cosmetic Exhibition www.cappmea.com/dental-confexpo +971 50 279 3711 CAPP DENTAL CONFEXPO DENTAL HYGIENIST SEMINAR CAPP DENTAL CONFEXPO Dental Technician Int’l Meeting 1 2 - 1 4 N O V 2 0 2 0 D U B A I , U A E 1 3 - 1 4 N O V 2 0 2 0 D U B A I , U A E 1 3 N O V 2 0 2 0 D U B A I , U A E
10 NEWS Dental Tribune Middle East & Africa Edition | 3/2020 Celtra Press: The most stable high-strength glass ceramic, regardless of testing method By Dentsply Sirona Zirconia-reinforced lithium silicate (ZLS) has been available from Dent- sply Sirona under the name of Celtra Press. With its three-point bending strength of more than 500 MPa, it has once again significantly raised the benchmark for high-strength glass ceramics. Experiments con- ducted by the University of Gies- sen, Germany have now shown that Celtra Press is clearly ahead of its competitors also in terms of biaxial strength. Internal measurements in a study of three-point bending strength have shown an average result of 567 MPa for Celtra Press.1 In comparison, the millable Celtra Duo ZLS (also from Dentsply Sirona) comes in at 210 MPa after finishing and polishing and at 370 MPa after optional glaze firing.1 This extends the range of in- dications of the pressable variant of ZLS for the dental technician, which provides a tangible benefit: Celtra Press can be used not just for single- tooth restorations but also for three- unit bridges with up to the second premolar as distalmost abutment. In addition to its superior three-point flexural strength, Celtra Press also exhibits the highest biaxial flexural strength among the high-strength glass ceramics, as researchers at the University of Giessen determined in recent laboratory experiments.2 The measured values were 678 MPa (Celtra Press), 413 MPa (Celtra Duo af- ter finishing and polishing), and 560 MPa (Celtra Duo after glaze firing) (Fig. 1, Table 2). Understanding strength measurements Product literature and technical pub- lications sometimes highlight a ma- terial’s three-point bending strength and sometimes its biaxial flexural strength. According to the relevant ISO 6872:2015 standard, both test- ing methods are acceptable, but the results can be properly assessed only by determining what values were ob- tained using which testing methods. An important thing to note is that the strength values obtained by the bi- axial test method are usually higher than those obtained by three-point bending test. The reason for that is that less effort is generally required to break the standard bar resting on two supports than the standard disk with three supports (Figs. 2 and 3).3 This is only partially compensated for by recalculation based on geom- etry data. In addition, the quality of the edge preparation in the biaxial samples is less important compared to the three-point supports. The exceptionally high strength of Celtra Press is ensured by the ad- dition of 10% of zirconia, which is completely dissolved in the glass matrix, and by a power firing step that is already integrated into the stain-and-glaze firing for monolithic restorations. But there is still another advantage of Celtra that will be im- mediately convincing to dentists: The material’s excellent surface properties permit intraoral polish- ing including, where required, finer occlusal adjustments—no separate glaze firing is required. Table 1: Both the three-point bending test and the biaxial testing method result in Celtra Press being top-of-the-class among its competitors. References 1. In-house measurements by Dent- sply Sirona. 2. Measurements carried out by the Department of Dentistry, Clinic for Dental Prosthetics, Justus Liebig Uni- versity, Giessen, Germany. 3. Yongxiang Xu, Jianmin Han, Hong Lin, Linan An. Comparative study of flexural strength test methods on CAD/CAM Y-TZP. Regen Biomater. 2015 Dec; 2(4): 239–244 Fig. 1: A new benchmark for the strength of high- strength glass ceramics: three-point and biaxial ﬂexural strengths compared. Fig. 2: In the three-point bending test, a bar resting on two supports is loaded from above with a punch until it breaks. Fig. 3: The biaxial testing method loads a disk on three supports. The results of this test are generally higher than those of the three-point bending test. Find out more by scanning the QR code. For more information about the full Dentsply Sirona portfolio please contact your local representative. Dentsply Sirona 21st Floor, The Bay Gate Tower Business Bay, Al Sa’ada Street Dubai, United Arab Emirates Tel.: +971 (0) 4 523 0600 Web: www.dentsplysirona.com/en E-mail: MEA-Marketing@dentsplysirona.com AD Light-curing micro-hybrid composite Applicable for various indications and all cavity classes High translucency and a perfect colour adaption Polishable to a high gloss Excellent physical properties for durable fillings High filler content Packable consistency (also available as Composan LCM flow) Kaltpolymerisierendes provisorisches Kronen- und Brückenmaterial, Paste-Paste-System Material provisório polimerizável a frio para coroas e pontes, sistema pasta-pasta 50 ml cartridge / mixing tips Made in Germany 0482 Temporary crown & bridge material Less than 5 min. processing time Strong functional load Perfect long-term aesthetics Excellent biocompatibility Glass ionomer filling material Variable mixing time for adjustment of consistency Modulation is possible right after insertion Perfect marginal adaption High compressive strength and abrasion resistance Easy activation without the need of an activator Perfect for smaller cavities and difficult to reach areas Visit www.promedica.de to see all our products Dental Material GmbH 24537 Neumünster / Germany +49 43 21 / 5 41 73 Tel. +49 43 21 / 5 19 08 Fax eMail firstname.lastname@example.org Internet www.promedica.de
Henrique José Piccin • Esp. Restorative and Prosthetic Dentistry MBA in MKT • National Sales Director of Bio-Art • Semi-Adjustable Articulators The importance of using Fig. 1 WRONG TRAJECTORY CORRECT TRAJECTORY Fig. 2
12 INDUSTRY Dental Tribune Middle East & Africa Edition | 3/2020 Minimizing the risk of sharps injuries with Hu-Friedy IMS System By Hu-Friedy Dental practices count on their in- struments day in and day out. But the same instruments that help den- tal professionals treat their patients effectively can represent safety haz- ards when not handled properly. Sharps injuries–punctures and cuts inflicted by instruments – are among the most frequent and most costly accidents that can occur in a dental practice. Sharps injuries aren’t merely painful. Dental instruments are routinely in contact with blood and other bod- ily fluids, and therefore, may carry dangerous infectious diseases such as hepatitis B and C, and HIV. The U.S. Centres for Disease Control and Prevention (CDC) estimates that the cost of treating each sharps injury in a healthcare setting can range from $500 to $3,000*. The CDC also notes that there are “harder to quantify costs,” including fear and anxiety, lost work time, and litigation. Dental instruments are always on the move. As instruments cycle through a dental office, they under- go cleaning and sterilization, wrap- ping, organisation and storage, prep- aration for procedures, and use with patient treatment. Almost every step along the way presents the potential for a sharps injury. Cassettes Accidental cuts and punctures hap- pen most often when instruments are kept and transported loose, rather than organized and stored in secure cassettes. The table attached shows how loose instruments can cause sharps injuries throughout the typical dental office workflow. taminated instruments directly. Once cassettes have been configured according to procedure, instruments remain secure throughout the re- processing cycle. The only time staff members make direct contact with any instrument is while treating pa- tients. How Cassettes Provide a Safer Experience Cassettes keep dental staff safe by reducing the need to handle con- Cassettes eliminate many of the dan- gers of working with loose instru- ments: · Instruments do not slide out or fall AD JOIN OUR COMMUNITY by implementing the Hu-Friedy Instrument Management System. That’s $57,310 over six months. A practice that performs 30 proce- dures a day may see an additional $171,930 over six months. The extra revenue comes from having more time to spend with current patients or take on new patients.** Hu-Friedy Instrument Management System even makes staff training easier. Every instrument has a spot within the cassette. Colour coding makes it simple to find the right pro- cedural set-up. If you’re interested in making your dental practice safer and more effi- cient, contact a Hu-Friedy represent- ative to learn more about getting started with the Instrument Man- agement System. * According to "SHARPS INJURY PRE- VENTION WORKBOOK" page 6. CDC (http://bit.ly/sharpinjuryprevention) ** When compared to single instru- ment decontamination - based on market survey results. Data on ﬁle. Follow us on @HuFriedyEU @hu_friedy_europe @Hu-Friedy Mfg. Co., LLC.EU off locked cassettes during transpor- tation. Instruments stay safe even if the cassette is dropped. · Cassettes can be placed directly into thermodisinfector and ultrasonic cleaners, rinsed, dried, wrapped, and then sterilized without removing instruments. No need for pouches – which can be punctured – or hand scrubbing. · Cassettes can be used to keep all the instruments required for specific procedures together. Clinicians do not have to sort through loose in- struments on a tray. Cassettes also prevent the spread of infection by helping ensure the proper placement of instruments in automatic cleaners and autoclaves. (If instruments cannot be processed right away, enzymatic spray can keep the bioburden on the instru- ments moist.) Efficiency Gains With Cassettes A dental professional’s time is best spent treating and caring for pa- tients. All too often, too much time is consumed searching for the right instruments to use for patient pro- cedures, cleaning and sterilizing in- dividual instruments, and moving slowly to avoid accidents. Cassettes can help dental practices get their time back. Practices that use Hu-Friedy’s cassette-based Instru- ment Management System (IMS) report saving 5 to 10 minutes per procedure**. Over the course of a day, that can translate into well over an hour. Another efficiency-boosting benefit of cassettes is that they prolong the life of instruments. Instruments can be bent, broken, or lost during the re- processing cycle, but cassettes keep them sheltered and secure in a pro- tective layer. Implementing an Instrument Management System An Instrument Management Sys- tem (IMS) based on cassettes organ- ized by procedure is not without its costs. Besides the price of the cas- settes, dental offices may need to up- grade their sterilization areas to see improved efficiency and productiv- ity immediately. But the investment will pay off in the long run. According to our calculations, a prac- tice that performs 10 procedures a day can earn an additional $521 daily For more information visit www.hu-friedy.eu, www.imsuser.hu-friedy.eu Hu-Friedy Mfg. Co., LLC. European Headquarters Astropark - Lyoner Str. 9 60528 Frankfurt am Main E-Mail: email@example.com Tel.: +49 (0)69 24753640 Fax: +49 (0)69 25577015 Free Call: 0080048374339 CHAIRSIDE When treating patients, clinicians must place instruments down and pick them up with care to avoid injuries. An assortment of instruments loose on a tray can also lead patients to question the cleanliness and organization of a dental practice. TRANSPORTING INSTRUMENTS TO AND FROM CHAIRSIDE In the hectic atmosphere of a busy dental practice, people can collide, trip, or run into objects in their haste. Loose instruments can slide off trays and inﬂ ict wounds. International and National Guidelines recommend that contaminated instruments must be transported in closed, puncture-resistant containers. RECEIVING/CLEANING Researchers at the New York University College of Dentistry conducted a 10-year survey and discovered that 31 percent of all exposures to blood in a dental ofﬁ ce***. happened during instrument cleanup – more than any other scenario. One reason for this is that dental professionals continue to scrub instruments by hand, risking sharps injuries, and exposure to aerosols and pathogens. Thermodisinfector and Ultrasonic cleaning technology negates the need for hand scrubbing, but instruments should be divided securely into cassettes. Dental ofﬁ ce personnel can get poked while placing loose instruments into and taking them out of the baskets of cleaning equipment. Loose instruments should not be bundled together with rubber bands, as it will prevent them from being properly cleaned. Another safety concern is that many practices do not use the correct personal protective equipment (PPE). The CDC and European Guidelines recommend the use of puncture- and chemical-resistant utility gloves when cleaning instruments. INSTRUMENT PREP AND PACKAGING Dental hygienists and assistants can get poked or cut while sorting and organizing instruments by procedure type or placing them in pouches before sterilization. While preparing for patients, staff must locate pouches and assemble instruments onto trays for treatment – all the while risking sharps injuries. STERILIZATION Loose instruments can puncture sterilization pouches and injure anyone who handles them. *** Journal of Dental Education - Volume 65, No. 5, 4/9/01. Occupational Exposures to Blood in A Dental Teaching Environment: Results of a Ten-Year Surveillance Study. Table 1
16 CAD/CAM Dental Tribune Middle East & Africa Edition | 3/2020 Highly esthetic results with CEREC® Primemill By Dentsply Sirona CEREC Primemill, Dentsply Sirona’s new milling machine, has taken chairside dental restorations to the next level. Thanks to its state-of-the- art technology, a wide range of res- torations can now be manufactured faster, using a large variety of materi- als with results that are very precise and particularly easy to achieve. Josef Kunkela, DMD, PhD, an inno- vative and renowned dentist and founder of the Kunkela Academy in the Czech Republic, has offered chairside restorations in his prac- tice for the past 13 years. As a clinical tester for Dentsply Sirona, he had the opportunity to comprehensively evaluate the new milling machine. The following is a description of his first experiences with CEREC Prime- mill based on a patient case. I have two essential requirements for digital restorative dentistry: I want to satisfy my patients to the best of my ability for example by producing accurately fitting and very aesthetic restorations. I also want to retain complete control over the workflow. This is exactly what CEREC has offered me for 13 years. It's not just about switching from conventional to digital impression taking, it's about the entire process. With the right workflow, I can work very efficiently. This is where CEREC Primemill takes us to a new level. It is a machine that is simple to operate, works with a really fascinating speed and yields high-quality results. As a beta tester of CEREC Primemill, I had the opportunity to follow the development process. When this milling machine was set up in my practice, I immediately noticed the new touch interface. In my opinion, it is a great feature to get informa- tion about milling cycles and the right instrument recommendation for every procedure. The second striking point is that the machine works very quietly and above all quickly. CEREC Primemill only takes approximately five min- utes using Super Fast mode to fabri- cate a zirconia crown. In my practice, the assistant takes over the first scan with the new CEREC Primescan. Af- ter I have examined the patient and made the therapy decision (which restoration, which shade), the assis- tant can prepare the CEREC Prime- mill. Meanwhile, I prepare the teeth to be restored and take the digital im- pression with CEREC Primescan. The fabrication process then starts di- rectly after the design of the restora- tion, which is carried out by a dental technician in my affiliated practice laboratory. I can fully concentrate on my work with the patient and on his dental situation. This is efficient and very important for me. Of course, a perfect workflow also re- quires the right quality. How useful is it to be finished with everything in the shortest possible time if the restoration does not fit exactly or is visually unattractive? This is where CEREC Primemill once again offers impressive results. The surface of the materials is extremely smooth and Fig. 1: Initial situation: The patient wants to have an aesthetic solution for her diastema. the margins are very clearly defined. From a clinical point of view, the fol- lowing aspects convince me above all else about CEREC: The entire scan- ning process, including bite regis- tration and preparation control, is very simple. In addition, there are the advantages of the initial scan: catalogue of beautiful natural smile, recycle patient smile, family cross copy smile, gingiva mask over de- sign proposal model, index for direct restorations. If you are going to fab- ricate a direct restoration of broken incisal edge or corner and if you would like to use layering technique, you benefit from having scanned the initial situation before and from having made a silicone index ac- cording to the 3D-printed model of patient's natural dentition. And there is greater patient convenience because of the reduction of appoint- ments for treatment and temporary restorations. From an organisational and economic point of view, the effi- cient workflow, the reduced number of appointments and the ability to delegate many work steps are par- ticularly noteworthy. My experience shows that CEREC begins to pay off at the reception desk when a well- trained assistant plans the appoint- ments and can explain the advan- tages of this treatment method to the patient. ÿPage 17 Fig. 2: This is the natural structure of the teeth we wanted to adapt in the ﬁnal restora- tions. Fig. 3: As there are different methods of copying natural teeth shapes, we decided to categorize them into these three categories of Biocopy. Fig. 4: Face scan for setting up the occlusal plane and the patient’s midline. Fig. 5: Mock-up design of the veneers in the inLab SW 19. Fig. 6: Try-in of the milled mock-up veneers. Fig. 7: Export of the data into the CEREC SW 5.1.1 and ﬁnal design of the veneers. Fig. 8: Milling preview. Fig. 9: Milled veneer in detail. Fig. 10: Inserting the veneers using rubber dam for perfectly dry luting surface. Fig. 11: Close-up of the veneer surface which shows the good adaption of the natural surface of the teeth. Fig. 12: Final situation – the new smile.
Dental Tribune Middle East & Africa Edition | 3/2020 ◊Page 16 CAD/CAM 17 The most important thing is that CEREC Primescan and CEREC Prime- mill work together to create a great setup for everyday restorative den- tistry. The CEREC system is excep- tionally versatile and allows us to freely scan, design and switch from laboratory to chairside software ac- cording to our requirements and the daily needs for different material choices and workflows. The follow- ing case illustrates this. Case study A 23-year-old female patient came to my practice and asked for an aes- thetic solution to her diastema and tremata. The challenge was to pre- serve the natural surface structure as much as possible. In this case we used the so-called Biocopy Stretch Tech- nique. It is a fairly simple technique that uses the scanned anatomy to create a larger version of the original while maintaining anatomical accu- racy. It is essential that the scanned anatomy is used for the restorations that are to be fabricated. At the same time, it is possible to build a custom tooth library in this way. This can be used for future restorations. This ini- tial scan also offers the possibility to use the gingival mask as a reference for the emergence profile when de- signing anterior restorations. With regard to the patient's youth, we opted for non-prep veneers for both the central and lateral ante- rior teeth. We used the initial scan to make a mock-up of the planned veneers in order to get a better idea of the final treatment result. We sent this scan via the Case Connect Cen- tre to our own laboratory where it was processed in the inLab software 19. To further modify the initial pro- posal, we used the aforementioned Biocopy Stretch Technique. Subse- quently, the virtual articulator was used to ensure function in all jaw movements lat- erotrusive). The mock-up was then milled from PMMA in an MC X5 (Dentsply Sirona). I prefer this meth- od to others because its distinct edge (protrusive and sharpness helps to avoid undercuts and transitions in the final restora- tions, especially laterally. The PMMA veneers were then temporarily fixed with a small amount of a flowable composite. A few days later, the patient returned to the practice. Depending on the de- gree of satisfaction, the veneers are either re-shaped or used directly as a template for the final restoration. In this case everything fit perfectly. We then imported the data seam- lessly from the inLab software into the CEREC software in dxd-format. In the CEREC software, we simply changed the material setting to com- posite block and then fabricated the veneers in the new CEREC Primemill. In doing so, we were able to achieve a high level of precision. We used the fine mode because it is ideally suited for the production of ultra-thin ve- neers. In order to maintain the high trans- parency of her natural teeth, the milled veneers were slightly cut back at the incisal edge and constructed with the same restoration mate- rial as the blocks used for milling. We then polished the surface in a two- stage system and bonded it adhe- sively under a rubber dam with com- posite. The result shows very natural anatomy of the anterior teeth. To sum it up: The CEREC system is exceptionally versatile in allowing us to freely scan, design and switch from lab side to chairside software and then mill or grind a restoration in the extraordinarily precise and ac- curate CEREC Primemill. Capturing the patient’s initial situation, posi- tion, shape and surface structure for potential future reference, which can also serve as donor anatomies for other patients, will serve more and more purposes not just in dental prosthetics but also for the manu- facturing of 3D models and silicone keys, which are then used for layer- ing restorative materials, digital im- plantology or dentures. Find out more by scanning the QR code. For more information about the full Dentsply Sirona portfolio please contact your local representative. Dentsply Sirona 21st Floor, The Bay Gate Tower Business Bay, Al Sa’ada Street Dubai, United Arab Emirates Tel.: +971 (0) 4 523 0600 Web: www.dentsplysirona.com/en E-mail: MEA-Marketing@dentsplysirona.com All-ceramic rehabilitation with CAD/CAM restorations made of a zirconia–reinforced lithium silicate (Celtra Duo) By Dr Tim Hausdörfer and Joachim Riechel MDT, Germany Abstract Patient: 55-year-old patient with an insuffi- ciently restored dentition and a re- duced vertical Dimension of occlusion. Challenge: The patient wanted an improvement in her anterior tooth aesthetics and a comprehensive oral rehabilitation. Treatment: A periodontal and conservative pretreatment was performed. The functional pretreatment included raising the bite using a centric splint. The posterior teeth were restored supplied with veneered crowns and bridges with zirconia frameworks. The aesthetic restoration of the max- illary anterior teeth was performed with crowns and veneers made of zirconia-reinforced lithium silicate ceramics (Celtra® Duo). Introduction Zirconia-reinforced lithium silicate ceramics (ZLS) have good mechani- cal and optical properties. Their mechanical strength makes them well-suited for partial and full poste- rior crowns and also—thanks to their good shade match and excellent pol- ishability—for aesthetic anterior res- torations (such as veneers). The pre- sent article illustrates the versatile application of CAD/CAM-made ZLS restorations (Celtra Duo; Dentsply Sirona Restorative, Konstanz, Ger- many) based on the complex case of a patient with extensive restorative treatment needs. Case report A 55-year-old woman presented at the Department of Preventive Den- tistry, Periodontology and Cariology of the University of Göttingen. The clinical and radiological examina- tion revealed an adult dentition that had been insufficiently treated with fillings and dental restorations and exhibited a loss of vertical di- mension of occlusion (Figs. 1 and 2). Insufficient restorations (secondary caries) were found on teeth 24, 25, 26, 27, 37, 38, 35, 47, and 48. The exist- ing bridge (17–15, 14) was insufficient due to extensive ceramic fractures. Part of the hard tissue of the upper maxillary incisors with their—some- times extensive—composite resto- rations had been lost to attrition and vestibular erosion. The endodontic ÿPage 18 Fig. 1: Clinical baseline situation Fig. 2: Radiograph of initial situation Fig. 3: Baseline situation for designing the aesthetic anterior restorations following bite raising in the posterior region Fig. 4: Mock-up Fig. 5: Preparation of the partial crowns and the veneers, occlusal view Fig. 6: Preparation, vestibular view Fig. 7: Impression taken with Aquasil Fig. 8: Digital model Fig. 9: Digital design of the restoration Fig. 10: Milled restorations ﬁt on the model Fig. 11: Single crown milled from a ceramic block Fig. 12: Final customized restorations after staining and glaze ﬁring
18 ◊Page 17 CAD/CAM Dental Tribune Middle East & Africa Edition | 3/2020 Fig 13 Fig 14 Figs. 13 and 14: Final restorative result after adhesive cementing Fig. 15: Preoperative smile and lip proﬁle Fig. 16: Postoperative smile and lip proﬁle treatment of tooth 34 was adequate, while tooth 46 required a primary endodontic treatment due to a ir- reversible pulpitis. All other teeth were vital and free of symptoms. The periodontal findings showed moder- ate gingivitis (periodontal screening index < 3 in all sextants). Teeth 13, 23, 24, and 43 additionally exhibited ves- tibular gingival recessions. In addition to an oral rehabilitation, the patient also wanted to improve her anterior tooth aesthetics. She first received extensive oral hy- giene instructions and professional tooth cleaning. The insufficient res- torations on teeth 24, 25, 26, 27, 35, 37, and 47 were replaced by call restora- tions (Luxacore; DMG, Hamburg, Germany) that were adhesively cemented (OptiBond FL; Kerrhawe SA, Bioggio, Switzerland). Teeth 38, 48 and the class V cavities of teeth 24 and 33 were definitely restored by direct composite fillings (Venus; Heraeus Kulzer, Hanau, Germany). The gingival recessions on teeth 13 and 23 were not surgical covered because a sufficient amount of at- tached gingiva was present and no further progression was observed. In addition, the patient had a low smile line, meaning that this posed no aes- thetic problems. A formal treatment plan and cost estimate was provided and checked by a dental expert of the patient’s health insurer. The following meas- ures were approved: Crown restora- tions for teeth 11, 21, 22, 24, 25, 26, 27, 35, 37, and 47 plus a remake of bridge 17–14. The functional pretreatment was performed with the aid of a centric splint in the maxilla which simulat- ed a bite raised by 2mm. The patient did not show any symptoms of my- oarthropathy or craniomandibular dysfunction after establishing her new vertical dimension of occlusion. In a first prosthetic treatment step, the posterior teeth were supplied with crowns (teeth 14, 26, 27, 37, and 47) and a bridge (teeth 17–15) in ve- neered zirconia. Teeth 32–42 were bleached and their incisal edges clinically lengthened by means of direct composite restorations (Es- sentia and G-Premio Bond; GC, Bad Homburg, Germany) in order to obtain a uniform aesthetic result. Within the framework of the Cel- tra Campus Challenge, the patient could be offered a cost-effective and aesthetic treatment offer upper jaw: Teeth 21 and 22 were restored with crowns and teeth 11, 12, 13, and 23 with veneers. In addition, teeth 24 and 25 received partial crowns. For the plan- ning of the ceramic restorations, a wax-up was created and developed into a composite mock-up (Figs. 3 and 4) (Luxatemp; DMG). The tooth shade (A2) was selected based on the Vita Classic shade guide (Vita, Bad Säckingen, Germany). AD The preparations (Fig. 5) followed the preparation guidelines for all- ceramic restorations1 and the ap- propriate minimum wall thickness requirements for lithium silicate ce- ramic restorations. The preparation for the partial crowns 24 and 25 had rounded interior line angles and a 90° shoulder at the preparation mar- gin. To prepare for the veneers (13, 12, 11, 23), approximately 0.5–0.7mm of hard tissue was removed on the labial aspect and a 0.5mm chamfer provided (Fig. 6). The intact proxi- mal surfaces remained untouched. Otherwise, the teeth were prepared for circular full veneers (“360-degree veneers”). The crowns of teeth 21 and 22 were prepared with a 1-mm circu- lar shoulder. Reduction of the incisal edges could be dispensed with as a consequence of raising the bite by 2mm. A conventional impression was tak- en of the prepared teeth and the casts were scanned. Prior to taking the im- pression, retraction cords (UltraPak; Ultradent, South Jordan, Utah, USA) were placed for gingival retraction around the prepared teeth. Retained proximal contacts were separated with thin matrix strips. The impres- sion was taking using and addition- type silicone at one time and in two phases (Aquasil; Dentsply Sirona Re- storative) (Fig. 7). The conventional impressions and casts facilitated the digital design process by providing a laboratory-made wax-up and sub- sequent adjustment of the restora- tions. This meant that hardly any intraoral adjustments were required. A vacuum-formed splint (Erkodent, Pfalzgrafenweiler, Germany) was first made with the aid of the wax-up, allowing provi- sional resin restorations to be pro- duced (Luxatemp; DMG). These were subsequently connected to the pre- pared teeth with Prime & Bond XP (Dentsply Sirona Restorative) and a flowable composite (Baseliner; Her- aeus Kulzer). transparent The restorations themselves were produced using the CEREC CAD/ CAM (Dentsply Sirona, Bensheim, Germany). To this end, the saw-cut models were scanned with a Blue- Cam (Dentsply Sirona) (Fig. 8). The teeth of the wax-ups were copied digitally and used for the design of the restorations (CEREC software v. 4.4 using the Biogeneric Copy op- tion; Dentsply Sirona) (Fig. 9). The restorations were milled from blocks of a zirconia-reinforced lith- ium silicate (Celtra Duo; Dentsply Sirona Restorative) of A2 HT shade, finished with water-cooled diamond cutters and adapted on the model (Figs. 10 and 11). Having ensured that the restorations were clean and free of grease and residue, they were customized with stains and glaze and subsequently fired. A more intensive shade effect (Fig. 12) was achieved by repeating cycles of applying and firing the ma- terial. The first stain/glaze firing took place at 820°C and the second one at a lower 770°C. The restorations were tried in with the aid of a glycerine-based gel (Try- In; Ivoclar Vivadent, Schaan, Liech- tenstein). Care was taken to ensure a good marginal fit, correct proximal contacts, a harmonious contour of the incisal edges and an appropriate shade. Minor corrections were car- ried out with a diamond cutter un- der irrigation, followed by polishing. After the try-in, the teeth were isolat- ed with rubber dam and cleaned. The ceramic restorations were etched on the adhesive surface using hy- drofluoric acid (Ultradent Porcelain Etch; Ultradent, South Jordan, Utah, USA) for 30 seconds and conditioned with a silane solution (Calibra, Dent- sply Sirona Restorative) for 60 sec- onds. The teeth were conditioned with 36% phosphoric acid (DeTrey Conditioner 36; Dentsply Sirona Restorative) for 30 seconds on the enamel and 15 seconds on the den- tin and subsequently with Prime & Bond® XP + Self-Cure Activator (Dentsply Sirona Restorative). Calibra dual-curing resin cement (Dentsply Sirona Restorative) was used for adhesively cementing the full and partial crowns. The veneers were used with a light-curing ce- ment (Calibra Esthetic Resin Cement, Dentsply Sirona Restorative). After thorough removal of any excess res- in and light curing, the occlusion was checked and the restorations were polished (Figs. 13 and 14). The zirconia-reinforced lithium sili- cate ceramics are characterized by good polishability and shade adap- tation to neighbouring structures (Figs. 15 and 16). Summary ZLS ceramics already have a high strength after milling2 and can be cemented adhesively immediately after polishing. In the present case, however, we decided to work with the laboratory to provide the res- torations, since many restorations have to be made at the same time and since the aesthetic result and the mechanical strength of the ce- ramic could be further improved by additional stain and glaze firing. The digital design of several restorations was considerably facilitated by the laboratory-made wax-up. By adapt- ing the restorations on the model, the patient’s chair time could be reduced. Adhesive cementing with Calibra was a very pleasant process, since any composite residue was easy to remove and the optical prop- erties of the ZLS ceramic were not ad- versely affected. Very good aesthetic results can be achieved with ZLS even for monolithic ceramic restorations. ZLS ceramics have improved me- chanical properties compared to lithium disilicate ceramics3. Howev- er, only a few case reports on clinical use have become available so far2, 4. Clinical trials are still pending. References 1. Frankenberger R, Mörig G, Blunck U, Hajtó J, Pröbster L, Ahlers MO. Prä- parationsregeln für Keramikinlays und –teilkronen unter der Berück- sichtigung der CAD/CAM-Technol- ogie. J Cont Dent Educ. 2007; (6), 86–92. 2. Rinke S, Schäfer S, Schmidt A-K. Einsatzmöglichkeiten zirkonoxid- verstärkter Lithiumsilikat-Keramik- en. Quintessenz Zahntech. 2014; 40(5): 536-546. 3. Elsaka SE, Elnaghy AM. Mechani- cal properties of zirconia reinforced lithium silicate glass-ceramic. Dent Mater. 2016; 32(7): 908–14- 4. von der Osten P. Zirkonoxidver- stärktes Lithiumsilikat für die Seiten- zahnversorgung. Quintessenz Zahn- tech. 2014; 40(7): 900-904. About the authors Tim Hausdörfer. Dr. med. dent. (Department of Preventive Dentistry, Peri- odontology and Cariology, University of Göttingen, Germany) Joachim Riechel. M.D.T. (Center for Dentistry and Oral and Maxil- lofacial Surgery, University of Göttingen)
20 GENERAL DENTISTRY Dental Tribune Middle East & Africa Edition | 3/2020 Fundamental principles in designing reprocessing areas By Christian Stempf, Austria It is recognized all too often that very little consideration is given to sterilization or reprocessing areas in either existing or newly designed dental practices. And yet reprocess- ing instruments between patients is crucial to meet today's hygiene rules in dental offices. Dental practition- ers also have a moral and legal ‘duty of care’ calling for effective, well- defined and implemented infection control measures to prevent the transmission of infectious diseases to patients and staff. Beyond the purely regulatory and safety aspects, many dentists have made the sterilization area a key asset for their activity. Located in a prime and visible location lets patients understand up front that their health and safety is important. The staff don’t hesitate to share this passion for hygiene with patients, happy to answer any questions they may have. Flattered by this attention, it makes the patient feel confident and secure. To create new reprocess- ing areas or enhance existing ones is not an "insurmountable" challenge. It simply requires some basic princi- ples this article will outline. Having sufficient space dedicated to the reprocessing area is essential. In most of the cases it is undersized. The room must be functional, well lit and in proportion to the size of the dental practice and volume of in- struments to be reprocessed. There must be space for cleaning and steri- lization devices with their respective accessories as well as enough bench space for intermediate stages i.e. before/after cleaning; before/after packaging and after sterilization. The first fundamental principal is to have two areas in the room; a dirty zone and a clean zone. Rationally, in- struments must travel in one direc- tion from the dirty zone towards the clean zone. As a consequence of this one-way flow, processed (clean) in- struments must not enter the dirty zone; hence one preferred design for a reprocessing area would be rectan- gular - a corridor with two doors (IN & OUT) (Fig 1). Both zones require ventilation and the airflow should be designed to prevent air from the dirty zone being forced into the clean zone. Where the areas are beside one another, this can be achieved by pressurizing the clean area though air conditioning outlets and/or hav- ing exhaust fans in the dirty area. At the entrance, there should be a hand washing basin equipped with an eye washing station, vital in case of accidental splashing of disinfect- ant or any harmful fluid. Liquid soap and hydro-alcoholic gel dispensers should have an automated dispen- sation (or elbow operated) which avoids contaminating them with soiled hands. It is recommended to pat dry hands with paper tissues. Form follows function The configuration of each part of the room follows the reprocessing steps i.e. pre-disinfection, rinsing, cleaning, rinsing, drying, packaging and sterili- zation. This room must not be used for any other purpose. Floors and working surfaces must be smooth, avoiding sharp corners and edges and be easy to clean and disinfect. Waste Waste should be disposed of into bags or containers through open- ings in the bench. Sharps and cutting items must be safely disposed of in specific plastic containers to protect staff, be collected and processed by specialized companies in treating contaminated waste. It is imperative to follow your local national guide- lines as they may vary from country to country. IN DIRTY ZONE OUT CLEAN ZONE Fig 1. Instruments must travel in one direction in the reprocessing area from the dirty zone towards the clean zone. Conversely, airﬂow should be designed to prevent air from the dirty zone being forced into the clean zone.1 e g a b r a G Sharp Basin 1 i c n o S r e n a e c l Basin 2 Disposal Soaking Rinsing Cleaning Rinsing Demin. water supply Fig 2. Dirty instruments are cleaned and rinsed on entry to the reprocessing area. e g a b r a G Sharp Basin 1 i c n o S r e n a e c l Basin 2 Area for drying / high- low-speed maintenance Area for storage prior to sterilization Area for cooling and labelling Disposal Soaking Rinsing Cleaning Rinsing Drying - HPs Packaging Sterilization Compressed air supply Fig 3. Clean and dry instruments are then packaged and sterilised Pre-disinfection – Soaking In order to prevent blood, saliva and debris from drying, all used and non- used instruments must be soaked as soon as possible after the procedure, using one or more disinfecting con- tainers depending on the number, type and size of the instruments i.e. a small one for burs and files, bigger one(s) for bulk of items, kits or cas- settes, etc. Note the manufacturer’s guidelines NOT to immerse or soak certain instruments such as trans- mission instruments in solutions! The manufacturer’s guideline on the concentration and contact time of the chemicals must be strictly ob- served. The temperature of the solu- tion should not exceed 40-45°C, thus preventing coagulation of blood pro- teins which increases the challenge of cleaning. Another benefit of this crucial first step is the reduction of the microbial population, decreasing the risk of infection during handling and clean- ing. A basin will permit rinsing of the instruments with tap water aiming to remove any residual chemicals particularly in hollow and hinged items. Chemical residues could lead to irreversible staining and damage to instruments should a thorough rinsing step be missed. Cleaning The cleaning step is of utmost im- portance. Mechanical cleaning by means of an ultrasonic cleaner offers a good level of performance. Note: Manual cleaning is discour- aged, as it is the least efficient method of cleaning particularly for complex or hollow instruments and rough surfaces. The degree of cleanli- ness relies on the operator's experi- ence and appreciation and also raises the risk to staff of skin penetrating injuries. In order to remove chemicals and bioburden, all instruments must be thoroughly rinsed with tap water in a second basin. Ideally this would be followed by a second rinse with dem- ineralized water to eliminate resi- dues and salts present in tap water that could lead to whitish stains on sterilized instruments. Washers or washer-disinfectors are a preferred mechanical cleaning method thanks to the higher per- formance of the cleaning cycle vali- dated by the manufacturer in com- pliance with stringent applicable standards (i.e. ISO-EN15833-1/-5). The cycle process includes pre-washing, rinsing, washing and drying without manual intervention which allows free space on the bench, sparing the soaking container/s and one basin. It is wise to keep the second basin. Buffer bench space after cleaning Next to the washing station, space is reserved to check the dryness, cleanliness and integrity of all instru- ments. Compressed air will assist drying hinged instruments (scissors, forceps, etc.) which may also require periodic lubrication. Transmission instruments will be maintained at the same place. Internal and external cleaning as well as lubrication should be mechanically assisted by means of an automated process validated by the manufacturer. It is virtually impossible to manually complete internal cleaning. Packaging – Sterilization An area should be considered for a pouch sealing device as well as an area for the temporary storage of packages prior to process in the bench top sterilizer. To ensure safe and efficient sterilization it is cru- cial to check the load and cycle–type for compatibility. Selecting a cycle which is not designed and validated for the type of load (instruments) will lead to non-sterile products. Additional space beside the sterilizer is intended for cooling and label- ling of packages which have been released by the operator for stor- age and use (Fig 3). Special attention must be paid to ensure that pouches are hermetically sealed and are com- pletely dry. Damp instruments/ packages are not acceptable as sterile. For extended storage time, pouched items should be stored outside the reprocessing area and surgery (op- eratory) in clean and dry drawers or cabinets. In doing so, single pouched items could safely be stored for up to 3 months. Conclusion All readers should reflect on these two definitions: Reprocessing: "All activities required to ensure that a used medical device is safe for reuse" (ADA Guidelines for Infection Control - 2012). "validated process Sterilization: used to render a product free from viable microorganisms". "…the presence of a viable microor- ganism on any individual item can be expressed in terms of probability. This probability may be reduced to a very low number; it can never be reduced to zero." (ISO/TS 11139:2006). In other words; the better each step is accomplished, the closer to "zero". Always bear in mind that each step of the reprocessing cycle is impor- tant. None shall be rushed or skipped which would compromise sterility and the safety of patients and staff. About the author Christian Stempf has worked extensively within the Eu- ropean dental industry. He has been in- volved in infection prevention for nearly 30 years, with focus on reprocessing reus- able medical devices, in particular steri- lization and organization of sterilization areas. He has gathered valuable practical knowledge and experience through his daily activities and contacts with health- care professionals and experts in the ﬁeld of infection prevention throughout the world. He is a member of the European (CEN- TC102) normalization committee partici- pating to two working groups i.e. bench top sterilizers (EN13060) and washer dis- infectors (EN15883). Christian shares this experience offering lectures in all objectivity on the topic of sterilization and infection prevention for healthcare professionals as well as com- prehensive courses for dental assistants worldwide.
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22 DIGITAL DENTISTRY Dental Tribune Middle East & Africa Edition | 3/2020 The copyCAD Fig. 1: Initial situation, smiling. Fig. 2: Initial situation, frontal view with lips retracted. Fig. 3: V-Posil impression. Fig. 4: Screenshot of the design software. Fig. 5: Structur CAD disc. Fig. 6: Screenshot of the nesting software. By Dr Yassine Harichane, France Introduction Nature has always captivated us with its beauty. Whether it is a landscape, a sunset or the intricate details of a leaf, one marvels at natural aesthet- ics. The goal of an artist is to copy nature in every medium: painting, sculpture, music, photography. It is easy to see parallels in dentistry. The teeth and soft tissue display details on the macroscopic and microscopic scale that make up all their beauty. Even the smile has characteristics that define what is beautiful and what is not. Like an artist, the den- tist and the dental technician use all their combined talents to create life- like restorations. The secret to imitat- ing nature is in the details of daily practice and hard work. Fortunately for dental practices and laboratories, technology has advanced considerably, making the ability to imitate nature much more achievable while paving the way for new practical methodologies. Performing a single restoration on a central maxillary incisor is a chal- lenge, both technically and artistical- ly. Whether it is a filling, a crown or an implant, all the skills of the artistic dentist must come into play because the patient naturally expects a result symmetrical to the contralateral tooth. Using the latest technology, it is as simple as the copy and paste function one is so accustomed to us- ing on a computer. The dentist has gone from being an artist to a com- puter scientist with the same optics: copying nature in all its perfection. On the basis of a clinical case with- out the utilisation of an intra-oral scan, I will demonstrate a workflow with CAD/CAM technology. This will show that the ability to copy nature has now become accessible to all practitioners. Preparation In this clinical case (Figs. 1 & 2), the patient wanted the aesthetic aspects of her smile to be improved without losing unique features she had come to consider as part of her look and personality. The maxillary anterior teeth showed caries and defective restorations, but their overall shape was satisfactory and they had a cer- tain charm despite their defects. Al- though her premolars did not have an optimal aesthetic appearance, the patient’s budget limited treatment to the incisors and canines. Fig. 7: Structur CAD provisional crown. Fig. 8: Try-in of provisional crowns. Fig. 9: Smile with provisional crowns. Fig. 10: Porcelain crowns luted with Futurabond DC and Biﬁx QM (VOCO). Fig. 11: Final result. The first step was to take an impres- sion of the preoperative oral condi- tion. Although the dimensions and appearance did not conform to all the rules of dental aesthetics, they would be preserved because they had characteristics specific to the pa- tient and they respected the occlusal dynamics. The impression of the teeth can be taken with an intra-oral scanner. However, the number of dentists who own intra-oral scanners is relatively low. The current mate- rials allow for a satisfactory phys- icochemical impression and remain accessible to all dentists. A polyvinyl- siloxane impression was performed in one step and two viscosities (V- Posil Putty Fast and V-Posil X-Light Fast, VOCO) to record the initial clini- cal situation (Fig. 3). Temporisation The second step was to prepare the provisional crowns by copying and pasting the patient’s teeth. After preparing the teeth, the impres- sion is sent to the laboratory, which will scan and design the provisional crowns. Most CAD/CAM software possesses this copy and paste func- tion (Fig. 4), so the scan and design processes take less than 1 hour. The six provisional crowns were then milled over the course of 1 hour and 30 minutes from a resin disc suitable for producing long-term provisional restorations (Structur CAD, VOCO; Figs. 5 & 6). Finishing the provision- al crowns—checking the contact points, controlling the occlusion and polishing—required 30 minutes, al- lowing delivery of the crowns two days after taking the impression. The result obtained was strikingly natu- ral (Fig. 7) thanks to the material’s aesthetic properties: natural shade, easy polishing and improvable with characterization. Concerning the form, the provisional crowns had an asymmetry that is found only in ÿPage 24
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24 ◊Page 22 DIGITAL DENTISTRY Dental Tribune Middle East & Africa Edition | 3/2020 nature, being both spontaneous and pleasant. They were temporarily ce- mented in the mouth to validate the prosthetic project (Figs. 8 & 9). The material’s biocompatibility clinically allows for a three-year maximum period in which the crowns can be worn, making it a material perfectly suited for complex cases, or those requiring periodontal rehabilitation. The material’s composition provides not only excellent resistance to abra- sion, but also the possibility of re- pair with a compatible composite. In this clinical case, the provisional crowns were kept in the mouth for one week—the time needed to pre- pare the definitive restorations. No defects were observed. Finalisation During the last stage, after the func- tional and aesthetic validation of the provisional crowns, definitive porcelain crowns (IPS e.max, Ivoclar Vivadent) were milled also by copy- ing the preoperative situation from the original scan. The provisional crowns were then removed, and the underlying teeth were cleaned. Af- ter fitting and validation within the mouth, the definitive crowns were luted (Futurabond DC and Bifix QM, VOCO; Fig. 10). The final result was a harmonious smile that did not dis- tort the features the patient consid- ered to be an important part of her facial personality (Fig. 11). Discussion Therapeutic success is measured by dental and periodontal health, as well as by patient satisfaction and feedback from the healthcare team. The skills of a caregiver are not lim- ited to making the right diagnosis or defining the ideal treatment plan; technical skills are essential and mimicking nature is a daily chal- lenge. Dentistry has come a long way with the introduction and implementa- tion of digital technologies, becom- ing faster and more precise as a result. These tools are becoming in- creasingly popular, and many prac- titioners are quickly equipping their offices and operatories. Contrary to what one might think, the acquisi- tion of an intra-oral scanner for the office is not an absolute obligation for one to take advantage of the digital dentistry revolution. Digital dentistry, above all, is a concept and we have just seen that it allows for an unsuspected and perhaps surprising function: copy and paste. The advantages of copying and past- ing are numerous and benefit every- one involved: dentist, dental techni- cian and patient. For the dentist, the main advantage of copying and past- ing is obtaining an intuitive result. On the one hand, the current materi- als (composite and porcelain), allow for a natural rendering. On the other hand, digital technology makes it AD possible to copy nature with all of her details. The use of computer- generated provisional restorations makes it possible to validate com- plex or demanding projects. In the end, restorations are both functional and aesthetic. They integrate per- fectly with the occlusion because no major changes have been made. In addition, they integrate with the overall harmony of the face. For the dental technician, the copy and paste function is part of his or her skill set. On the one hand, the lab- oratory scanner can capture every detail of the dental arch. On the other hand, milling machines can deliver strictly identical crowns over and over again as needed. The milling of a provisional disc or block will there- fore validate the therapeutic project before moving to more expensive materials such as zirconia or lithium disilicate. In the same way, if re- turned to the laboratory, the cost will be lower by using a millable tempo- rary resin. After provisional crowns are validated, the dental technician only needs to press a button to start producing the definitive crowns in the desired material. For patients, digital dentistry is an education on just how far dentistry has evolved: technological advance- ments in clinical procedures are re- placing many of those treatments of their bad childhood memories. It is now possible for the patient to re- claim the smile of his or her twenties. Better still, it is possible to copy the child’s juvenile smile and place it in the deteriorated dental arch of the father. The smile will become a lega- cy that will be passed down through families. Conclusion Technology is making significant progress in dentistry, it is up to us to appropriate it. The emergence of new tools, such as intra-oral scan- ners, and unique new materials, like millable temporary resins, makes it possible to develop new therapeutic concepts and procedures. Copying and pasting is now a part of the den- tist’s, and dental technician’s, thera- peutic armamentarium. A copycat is an artist who tries to capture na- ture in all its glory through painting. Now, a copyCAD is an artist who can capture nature in all its perfection through CAD/CAM technology. Acknowledgements The author wishes to thank Matthias Mehring of VOCO for his friendly support and support with materials. The author congratulates French cer- tified dental technician Christophe Giraud for his talent and skills. The author is grateful to Tom Kershaw and Russ Perlman of VOCO America for proofreading and improving this article. Editorial note: This article was originally published in digital-international magazine for digital dentistry, Issue 1/2020. About the author Dr Yassine Harichane graduated from the Paris Descartes Uni- versity and conducted several research there. He is an author of numerous pub- lications and a member of the Cosmetic Dentistry Study Group (CDSG) at the Paris Descartes University in Paris, France.
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26 RESTORATIVE Dental Tribune Middle East & Africa Edition | 3/2020 Meeting patients' needs and transforming smiles with direct veneers By Dr Mohammad Zuhair Al Khairo, UAE Introduction "I can`t afford e.max veneers, do you have something more affordable?" is a question often encountered in clinical practice today! Being a restorative dentist with more than 15 years of experience in pri- vate practice, I have been asked this question innumerable times. With the recent advances in direct resin technology, I am able to confidently say “YES” and provide an alternative of composite resin-bonded veneers with an emphasis on preserving tooth structure. The next question the patient asks with much anticipa- tion is “what is the difference?. Since I started using a nano-hybrid, bioac- tive composite resin with a porcelain like shade, the one-word answer to this question is "COST!!". Compared to a decade or two ago, to- day we encounter more internet-in- formed patients who visit the clinic with a preconceived notion, which, you are expected to fulfill. Therefore, the dynamics of treatment planning has changed towards providing a suitable solution while managing patient expectation. The advancement in composite resin technology with natural shade replication has created an avenue for clinicians to offer highly stand- ardized, predictable restorations in terms of aesthetics, strength, polishability and durability. Shofu composites are unique as they are bioactive and provide an additional acid neutralization and anti-plaque effect to minimize caries risk while enhancing longevity of the restora- tions. Being a firm believer in prevention and minimally invasive treatment, we follow a stringent prevention protocol that I call "3X Protocol". Part of this protocol emphasizes "X for Prevention from eXtension" which has been modified from GV black principle "Extension for Prevention". Another " X” for eXpenditure", evalu- ates the cost benefit and to provide cost-based treatment options to the patient. The final “X” would be man- aging patient eXpectation as this is a crucial element of cosmetic den- tistry. The “3X Protocol” has enabled us to provide a more conservative patient-centred treatment with the desired aesthetic outcome while pre- serving natural tooth structure. The patient case presented below is an anterior diastema with old dis- coloured composite restorations. In clinical situations with multiple diastema, It is important to first evaluate treatment options from a restorative point of view before con- sidering orthodontic treatment. In order to achieve long-term stability and predictable outcomes over time, the restorative plan should consider different aspects such as: 1. Arch /space discrepancy in rela- tion to occlusion. 2. Restorative material of choice 3. Biological cost and patient’s finan- cial limitations. Patient case A young female patient visited the clinic requesting for an enhanced smile as she was unhappy with the appearance of her front teeth after completing orthodontic treatment. Upon careful examination it was ob- served that composite resin restora- tions were used for diastema closure before orthodontic treatment (Fig 1, 2). The filled teeth had chipped at the incisal edge and had a grey dis- colouration. After careful evaluation the following treatment options were suggested to the patient: 1. e.max veneers with minimum tooth preparation, 2. Direct resin-bonded veneers with no tooth preparation. Fig 1: Pre-operative macro view of patient smile Fig 2: Pre-operative retracted view Fig 3: Smile after removal of old restorations Fig 4: Retracted view after removal of old restorations Fig 5: Digital Smile Design Fig 6: Indirect wax-up Fig 7 : Direct mock-up to assess occlusion and obtain patient approval Fig 8 : Silicone Index fabricated with putty impression material Fig 9 : index with incisal wrap to help duplicating the thickness of the incisal edge Fig 10 : Direct placement technique for shade selection Fig 11 : Final recipe of shades for the restoration Fig 12 : Shade conﬁrmation using the Isolate Shade Mode of EyeSpecial CII camera After the treatment planning discus- sion, the patient requested to pro- ceed with direct resin-bonded com- posite veneers to enhance her smile. After the old composite fillings were removed (Fig 3, 4), smile design, was done to restore the golden propor- tion by modifying the shape and size of the teeth. Based on the smile design a mock-up was created to help obtain patient approval on the expected outcome and fabricate the silicone index. Materials used - Prepare: Shade Selection & case doc- umentation - EyeSpecial C II (Shofu) - Restore: Beautifil II LS shade A2O, A1, Beautifil Flow Plus F03 shade INC and Beautifil II Enamel HVT Com- posite (Shofu) - Finish: Yellow banded Fine dia- mond bur, Super-Snap Black disk, for contouring and Super Snap Purple disk for finishing (Shofu) - Polish: OneGloss polisher, Super- Snap X-Treme Green and Pink disks - Super polish: Super Buff impreg- nated buff disk for enamel like lustre (Shofu) Restorative approach: Smile design Digital Smile Design DSD, was used to reestablish proper proportion of the teeth and redesign the smile ac- cording to lower lip line, (Fig 5). Tip: Smile design is a great aid to establish correct golden proportion and help convince the patient on the treatment plan Wax-up Indirect wax up was performed ac- cording to the smile design, (Fig 6). Tip: Since it is a prepless case the lab should be informed not to prepare the cast during wax-up. Direct mock-up Silicon mold was used to create a direct mock-up trial to ensure pro- portion compatibility, occlusion and obtain patient approval. Tip: checking the occlusion at this stage helps identify the points of in- terference that might affect the final restoration design and minimize ad- justments. Silicon index Silicone index with putty impres- sion material was used to create the palatal shell of the restoration for each tooth separately (Fig 8). Tip: make the index with incisal wrap to help duplicating the thick- ness of the incisal edge (Fig 9). Shade selection Accurate shade selection was carried out using the direst technique where small buttons of each composite material was placed directly on the tooth surface. Beautifil II LS shade A2O was identified for Hue specifi- cation, Beautifil II Enamel HVT was identified to restore the value since the case involved bleaching ten days prior to the restorative procedure. Beautifil II LS shade A1 and B1 were compared under Shade Isolate Mode using EyeSpecial C II to determine the ideal Chroma and shade A1 was identified as the most suitable shade (Fig 10, 11). Beautifil Flow PLUS F03 INC. shade was selected to create the palatal shell. Fig 13: Shofu EyeSpecial camera Fig 14: Natural aesthetics achieved with direct veneers Fig 15 : Patient smile post treatment ÿPage 27
Dental Tribune Middle East & Africa Edition | 3/2020 RESTORATIVE ◊Page 26 Tip: Shade Isolate Mode removes the influence of the background gingival colour and helps obtain a more accu- rate shade selection (Fig 12, 13). Composite layering Teeth were polished using non-fluor- idated paste, etched and bonded. Restoration of each tooth was com- pleted separately in a progressive manner according to a customized colour scheme, (Fig 14) - Palatal shell was created using the silicone index with a very thin layer of Beautifil Flow Plus F03 shade INC composite - Proximal walls were created using Beautifil II LS shade A1 with a layer of Beautifil II Enamel shade HVT on top - Beautifil II LS shade A2O was used incisally as a very thin line to help recreate the Halo effect and placed cervically as the first dentin layer, Beautifil II LS shade A1 was used to build-up the body dentine layer leav- ing to restore dentine colour leaving 0.5mm for the final enamel layer with Beautifil II Enamel shade HVT (Fig 14). Tip: - A flowable composite Beautifil Flow Plus F03 should be used to create a thin palatal shell and ensure adapta- tion to tooth structure. - A kidney shape matrix band was adapted to create the proximal walls and the contact with the adjacent teeth. Lateral incisors were restored before the central incisors to help reduce finishing time and material wastage. - Use a brush such as Uni Brush (Shofu) to adapt the composite and refrain from using a resin liquid as it affects the composite colour • Final layer of enamel should be 0.5mm all around to ensure uniform finish with proper shade characteris- tics Contouring and finishing protocol - Yellow banded Super Fine Diamond burs in high speed and Super-Snap Black disks in low speed were used to contour and create a uniform sur- face. - Super-Snap Purple disks were used to create the mesial and distal reflec- tive line angles. - One Gloss polisher was used in the cervical area and to achieve the natu- ral surface texture. - Super-Snap X-Treme Green and Pink disks were used to polish the restoration. - Super Buff impregnated super pol- isher was used for final polishing to achieve enamel-like luster. Results and conclusion The planned cosmetic restorative treatment with non-prep compos- ite resin veneers was successfully completed and the patient was ex- tremely happy with her enhanced “natural” smile (Fig 14, 15). The em- phasis on shade selection and adop- tion of the 3X protocol which takes into consideration “prevention from eXtension” by avoiding over-prepa- ration, “prevention from undue eX- penditure” by eliminating cost while maintaining quality and “managing patient eXpectations”. As a clinician, our final aim with cosmetic treat- ment is to recreate a natural smile that meets or exceeds the patient’s expectations while ensuring longev- ity of the restorations. This concept can be easily achieved today with the help of innovative, bioactive com- posites capable of recreating natural life-like aesthetics with a predictable outcome. About the author Dr. Mohammad Zuhair Al Khairo Dr. M. Zuhair AK., earned his bachelor degree in dental surgery from Mosul Uni- versity, Iraq in the year 1999 with the degree of honour. Two years later he specialized and trained in Conservative Dentistry where he was mesntored by the renowned Prof. Abdul- Haq Abdul Majeed Suliman. At the department of Conserva- tive Dentistry, Mosul University, Iraq. He had his own practice in Iraq early in year 27 2001 where he gained a very big repu- tation for his delicate, professional and honest way of dealing with his patients. In the year 2005 he moved to Dubai UAE to extend his experience across a different parts of the globe. His settling in Dubai for more than 8 years now gave him the chance to give his imprint by practicing international quality healthcare stand- ards which has been internally developed and continuously improved over the years through rigorous clinical compli- ance parameters. In year 2013 he gained the German Board of Oral Implantology from Muenster University/DGZI with the ﬁrst degree of honour among 29 stu- dents. Since then he has been awarded the membership of the German Associa- tion of Dental Implantology DGZI. Today, Dr. M. Zuhair`s philosophy of dental care is more and more towards developing a high standard dental practice that offers a good quality dental service through combining the experience of a highly trained team and state of the art dental equipment. Mectron launches own continuing education platform By Dental Tribune International The dental community is facing extraordinary times, and it has re- sponded by adapting and imple- menting new strategies. This is also true for continuing education (CE) in dentistry. Embracing the opportuni- ties of e-learning, Italy-based den- tal company mectron has recently launched a webinar platform, which will provide dental professionals ac- cess to clinically relevant presenta- tions 24/7 free of charge. The new industry-wide dental CE platform delivers free CE accredited content through the convenience of the Internet. After quick and easy registration, dental professionals will be able to attend live webinars and watch recorded webinars on- demand, and these will cover a wide range of topics relevant to the oral healthcare professional commu- nity, including implant treatment and prophylaxis. Twelve webinars in English, French, German, Italian and Portuguese are already planned and will become available soon on the platform. More webinars will be scheduled in the second half of this year. Andre Reinhold, mectron’s interna- tional marketing manager, told Den- tal Tribune International that the company had been planning to start a Web-based education platform for some time already. However, the AD EssenSeal® THE POWER OF TEA TREE Join MyPD and get access to unique materials, case studies, clinical articles and webinars. Visit pd-dental.com for more information P r o d u it s D e recent COVID-19 outbreak and the related restrictions on travel and events, which have rendered main- taining customer relations almost impossible, prompted mectron to go online now. “E-learning has become an effective tool for us to stay in contact with our customers and reach out to new customers, especially in regions in which mectron does not yet have a local branch,” Reinhold said. “Al- though this online platform cannot replace physical presentations in the long run, it definitely facilitates access to and helps raise interest in our products. Through the webinars, dental professionals are provided with a comprehensive overview of the advantages of our products in daily practice,” he explained. The feedback has been overwhelm- ingly positive. “Within the first week of the launch, over 1,300 members registered. The registrations for the single webinars have also exceeded our expectations,” Reinhold stated. Since 1979, mectron has been one of the major players in the interna- tional dental industry, producing surgical, ultrasonic, air polishing and LED polymerisation devices, which are available in over 80 counties worldwide. With the introduction of the first ultrasonic titanium hand- pieces, the first LED polymerisation lamps for composite materials and, in 2001, the first ultrasonic surgical unit for piezoelectric bone surgery, mectron has developed some of the most important innovations in the dental field. n t air e s S A . V e v e y . S w it z e rla n d More information about upcoming webi- nars can be found on the platform web- site at https://education.mectron.com/.
28 RESTORATIVE Dental Tribune Middle East & Africa Edition | 3/2020 Testing a novel endodontic sealer By Drs Paolo Generali and Francesca Cerutti, Italy The aim of endodontic treatment is to eliminate microorganisms and their byproducts from the root canal system, together with avoiding its re- contamination1-3. The outcome of en- dodontic treatment is strictly linked to several steps: root canal debride- ment, disinfection protocols, her- metic obturation of the canal space4. Root canal obturation in a 3-dimen- sional space with a stable, nontoxic material and the creation of a tight seal is fundamental for the success of the treatment, since the root filling seals the communications between the periodontium and the endodon- tium and, along with shaping and disinfection, allows a further bacte- riological defense5, 6. Sealers should be used to fill the morphologic root canal system ir- regularities, to avoid gap formation between the dentinal walls and core materials; moreover, sealers should facilitate the placement of the fill- ing core with a lubricant action, penetrate into dentinal tubules to prevent microleakage and entomb any remaining bacteria2, 7, 8. Many different sealers are available on the market, but all of them ideally aim to have the following features: tissue tolerance, no shrinkage with setting, slow setting time, adhesiveness, ra- diopacity, bacteriostatic properties, absence of staining, solubility in sol- vents, insolubility to oral and tissue fluids, easy handling9. The different endodontic sealers are categorized basing on their main components: zinc oxide eugenol (ZOE), calcium hydroxide, glass iono- mer, resin-based, polydimethylsilox- ane (silicon)-based and bioceramic- based sealers. Resin-based sealers became popular because of their adhesive properties and have been reported to be used with single gutta- percha cone technique for canal ob- turation; even bioceramic sealers can be used with this last technique11. The most commonly used sealers in root canal treatment are ZOE-based sealers, modified for endodontic purposes based on Grossman or Rickerts’s formula. The powder of these sealers contains zinc oxide (ZnO), which combines with a liquid, generally eugenol. ZnO is an envi- ronment-friendly material, which has been used widely in medical ap- plications, with antibacterial proper- ties and favorable characteristics in terms of biocompatibility. Unlike resin-based sealers, which are subject to shrinkage, setting reaction of ZOE- based sealers is a chelation reaction occurring between eugenol and the zinc ion of the zinc oxide; this reac- tion might also occur with the zinc oxide phase of gutta-percha along with the calcium ions of dentin. This might explain the decreased setting shrinkage associated with the ZOE- based sealers10. Michaud et al.12 have shown that vol- umetric expansion of gutta-percha (almost 135.35%) occurred in contact with eugenol during a 30-day pe- riod, and a pilot study done earlier showed a remarkable increase in the gutta-percha dimensions when placed in eugenol that continued even after 4.5 years. Theoretically, sealer penetration into dentinal tubules could improve seal- ing of a root filling by increasing the surface contact area between the root filling materials and dentinal walls. Furthermore, retention of root filling Fig. 1 material might be improved by me- chanical locking. However, contrary to common belief, a positive correla- tion between sealer penetration into dentinal tubules and sealability has never been established13. Fig. 2a Fig. 2b Fig. 3 Fig. 4 Penetration refers to the amount of sealer entering the dentinal tubules and adaptation qualitatively de- scribes the way in which the sealer conforms to the dentine wall. Pen- etration and adaptation depend on many factors, including the patency and density of the dentinal tubules14. A study by Russell et al15 investigated the penetration and adaptation of common types of root canal seal- ers (AH Plus, Kerr Pulp Canal Sealer, MTA Fillapex and EndoREZ) in cross- sections of tooth roots exhibiting the butterfly effect and to determine if this differs between coronal and middle root sections. Penetration and adaptation quality varied be- tween obturation material groups but this did not reach significance, reporting AH Plus as the most per- forming material between the tested cements and Pulp Canal Sealer and EndoREZ as the less performing. The superior adaptation and penetration of a sealer may be attributed to its pseudoplastic behaviour inside root canals; this has been described as a decrease in viscosity and an increase in flow parallel to an increase in shear rate during filling procedures. When using gutta-percha with sealer as core material for filling the canal space; the amount of sealer should be kept at the lowest, whereas the amount of gutta-percha placed into the canal must be maximized 16. To reach the ideal consistency of the sealer, it is important to calibrate the powder/liquid or paste/paste ratio of the mixed cement, because even small alterations to this ratio may cause a change in thickness and flow of the material, affecting its penetra- tion and adaptation to the dentine. ZOE cements have some drawbacks, such as the capability to stain the tooth and to have a setting time de- pending on the heat/humidity of the environments. In order to improve ZOE powder- liquid sealers, many attempts have been done, adding various substanc- es or substituting Eugenol in the Fig. 5 Fig. 6 ÿPage 29
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