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24 ◊Page 23 RESTORATIVE Dental Tribune Middle East & Africa Edition | 6/2017 With improvements in materials and advancements in CAD/CAM technology (Fig. 10), full-arch pros- theses can now be precisely milled from monolithic zirconia, offering aesthetics and functionality with the added benefi t of long-term durabil- ity. Exhibiting exceptional fracture toughness and fl exural strength, Zenostar zirconia has the ability to withstand the functional stresses that full-arch implant restorations are subject to over time. Unlike hybrid dentures, the entire body of the Zenostar Implant Pros- thesis (Arrowhead Dental Lab) in- cluding the gingival and tooth areas is constructed from the same robust material. The strength and durability offered by Zenostar is complement- ed by lifelike aesthetics and excel- lent translucency. The teeth of the prosthesis exhibit colour that is very similar to natural dentition, and ad- vanced staining techniques are used to establish gingival areas that blend well with the patient’s soft tissue. Within three weeks, the defi nitive maxillary and mandibular restora- tions were delivered from the den- tal lab (Fig. 11). Utilising a right angle prosthetic driver, both provisionals were removed and the defi nitive res- torations inserted (Figs. 12 & 13). Care was given to torque the retention screws according to the manufac- turer’s recommendations. A Panorex X-ray was taken to verify the restora- tions were completely seated. Once confi rmed, a piece of Tefl on tape was placed followed by composite mate- rial (Figs. 14 & 15). The occlusion was checked and verifi ed with the T-Scan (Tekscan) to make sure that all the proper points of contact were in their ideal positions to ensure longevity of the reconstruction. The patient no longer experienced pain and was very pleased with her new enhanced ‘whiter’ smile (Fig. 16). Conclusion Computer generated 3-D virtual treatment plans allow the dental provider or team to accurately place dental implants effi ciently and ef- fectively. With a variety of different software and associated surgical instrumentation available, dental implant diagnosis and treatment has become more simplifi ed. This development has created an inter- disciplinary environment in which better communication and precise execution leads to better patient care and outcomes. Dr Nazarian main- tains a private prac- tice in Troy, Michigan with an emphasis on comprehensive and restorative care. Dr Nazarian is the direc- tor of the Reconstruc- tive Dentistry Institute. He has conducted lectures and hands-on workshops on aesthetic materials and dental implants throughout the United States, Europe, New Zealand and Australia. Dr Nazarian is also the creator of the DemoDent pa- tient education model system. He can be reached at www.aranazari- andds.com. Removal of leaking amalgam restorations and placement of ceramic CAD/CAM inlays in one-hour appointment By Dr. Richard WH Pollock B.D.S. Case characteristics Age: 39 years old Gender: Female Area of restoration: Upper and low- er fi rst molars Teeth numbers: 16, 46 Reason for treatment: Patient want- ed a long-lasting aesthetic restora- tion in one visit due to busy work schedule. (Fig. 1, 2) Introduction With the information now avail- able to the general public through internet access, many patients of- ten come to visit a dentist already armed with some facts they have re- searched. This also fuels the attitude of, “l'm too busy to keep coming to see the dentist- I need it all done in one visit." This study shows how to achieve high quality long-lasting aestheti- cally pleasing restorations by using MyCrown technology. Patient fi rst contact A 39-year-old woman attended our clinic complaining of increased dis- comfort coming from her two fi rst molar teeth when biting. This had been increasing in intensity over the last few months but her busy work schedule had caused her to continue putting off making an appointment. Although the pain she was expe- riencing was only a mild irritation over the last week she had reported noticing a slight metallic taste also, which spurred her on to make the appointment. On examination, teeth 16 and 46 had amalgam restorations, with defec- tive margins and signs of corrosion of the metal into the surrounding dentinal tubules. Tooth 46 had a ver- tical fracture running from occlusal surface to 1mm coronal if the gingiva on the palatal aspect. Neither tooth was tender to percussion and both scored positively with electric pulp testing. However, 46 did have pain on release when biting on the palatal cusps of the crack fi nder. The patient confi rmed this was the sensation she had been experiencing over the last few months. Two periapical radio- graphs confi rmed caries under each amalgam restoration but no evi- dence of periapical pathology. I suggested removing each amalgam restoration and any stained dentine and fractures and restoring the teeth with Inlays fabricated by CAD/CAM Fig. 1 Fig. 2 Fig. 3: Upper jaw Fig. 4: Lower jaw system, MyCrown. Treatment with MyCrown The amalgam restorations were re- moved with high volume suction, Swedish clean up suction tips, maxi- mum water fl ow with High speed hand piece. Appropriate supple- ments were given to the patients to assist in detoxifi cation and fl ushing the body of any amalgam particu- late which entered the throat and gut. The carious and stained dentine, and fractured weakened enamel was removed with slow speed and maxi- mum water fl ow. A dry pad was used in the buccal mu- cosa to soak up saliva and keep a dry fi eld. High volume suction with a sa- liva ejector ensured dry fi eld to assist scanning each of the teeth. Having achieved a dry fi eld, which is essential for every digital impres- sion/scan, an OptraGate lip retractor was inserted and HD FONA spray was used on the prepared teeth. Spray was applied on one tooth medial and distal and the buccal and palatal gingival. Ensuring some gingivae is sprayed and scanned increases the ease of taking the digital impression and assists when it comes to taking the buccal scan for the camera to lo- cate and orientate. The beauty of using this technology is both prepared teeth were designed at the same time which is a huge sav- ing in clinical time. Having sprayed, then scanned each arch, then a buccal scan with the patient in centric occlusion, the My- Crown software correlated all the information and gave images of the upper lower and buccal scans. (Figs. 3, 4, 5, 6) Choosing one prepared tooth fi rst, the software asked me to create the restoration margin line. This is the yellow line, seen in the next two im- ages. Then, moving to the other pre- pared tooth doing the same. Then moving to the next stage, the soft- ware gives an initial proposal for the restoration based on cusp height if the prepared tooth and those of the neighboring teeth. Minor adjustments were made us- ing the form tool which allowed me to add, remove and smooth small increments of tooth structure and volume to create a functional, non- traumatic occlusion with the res- torations. There are various tools available to easily and extremely accurately modify the size and shape of the restoration if desired. The restorations have color coding where contacts in the occlusion are too heavy, which can be very trau- matic to an occlusion in the sensitive patient. Once satisfi ed with the adjustments, the manufacturing unit processed one restoration at a time. (Figs. 7, 8) Each restoration was manufactured in less than 7 minutes! (Figs. 9, 10) Having tried the restorations in and polishing off the remnants of the ceramic sprue, the restorations were ready for cementation. Using ceramic etch of 9% Hydro- fl uoric acid the fi tting surface of the restorations were left for 20 seconds before rinsing this off and applying a Bisco 2-part Silane primer. The tooth was etched and bonded with Scotchbond, and the restora- tions were bonded into place with RelyX ultimate. The occlusion was checked with fi t- ting result and patient said it felt good and the opposite arch was clos- ing fully. The restorations were polished us- ing brown, green and blue amalgam polishers with maximum water fl ow using the slow speed handpiece. The patient was called the following day and reported complete satisfac- tion with aesthetics, no afterpain and said her "bite feels normal". (Fig. 11) Fig. 5: Bite Fig. 6: Model Fig. 7: Design 46 Fig. 8: Design 16 Fig. 9: Manufacture 16 Fig. 10: Manufacture 46 Fig. 11: End result Conclusion This clinical case demonstrates the ease and effi ciency of providing high quality aesthetically superior resto- rations with minimal inconvenience to the patient. The patient was given the option of having composite resin placed in- stead of using MyCrown technology and this would have taken longer to provide a poorer quality restoration. It's a no-brainer for the patient and for the dentist! 5 simple steps to ultimate quality. Dr. Richard W. H. Pollock B.D.S. He works in three practices in London practicing cosmetic dentistry, implant surgery and safe removal of amalgam and detoxifi cation- he has had a special- ist interest in CAD/CAM dentistry over the last 15 years. Having successfully placed over 10,000 restorations in many satisfi ed patients, using earlier versions of CAD/ CAM technology, he is delighted to now be a proud user of MyCrown technology which he fi nds to be superior in every as- pect of use, design and manufacture. He qualifi ed from the University of Dundee in 1999.