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Dental Tribune Middle East & Africa No. 4, 2016

Dental Tribune Middle East & Africa Edition | 4/2016 22 RESTORATIVE User case study on the new composite bloc BRILLIANT Crios by COLTENE in the fabrication process of a CAD/CAM CEREC crown By Dr. Med. Dent. Christoph G. Hüskens,Switzerland The application fields of the new composite bloc include crowns, in- lays, onlays and veneers as well as implant-supported crowns. BRIL- LIANT Crios is a reinforced compos- ite bloc for the fabrication of perma- nent restorations using a CAD/CAM millingprocess. This is available in Low Translu- cent (LT) and High Translucent (HT) shades and in sizes 12 and 14. The material properties allow extended processing: easy preparation, ta- pered margins and polishing. In ad- dition, the BRILLIANT Crios bloc can berepairedwithmethacrylate-based composite materials. As part of ma- terial sampling, a 34-year old patient in this case required a newly fabri- cated restoration after losing a full ceramiccrownduetofracture. Thepatientpresentedwithamissing restoration on tooth 37. The X-ray of the untreated stump (Fig. 1) shows the tooth with a root filling and a composite abutment post (this res- toration was performed by a differ- entdentist). Due to the loss of the full ceramic crown, the patient was willing to haveanewrestorationfabricatedus- ing a CEREC crown made of the new composite-based BRILLIANT Crios (COLTENE) CAD/CAM material. The existing tooth stump 37 required ad- ditional preparation to meet the fol- lowingcriteria: -Minimalocclusivethickness1.5mm -Minimalbuccalthickness0.8mm - Minimal thickness under support- ingcusp1.5mm -Minimalcervicalthickness0.8mm Occlusal corrections and additional preparation of the transitions to the distal stage were required in this case. The existing deep distal stage on tooth 37 also proved problematic in this clinical situation. We there- fore decided on a squeeze bite im- pression with an A-silicone (AFFINIS, COLTENE) as experience has shown direct optical impression taking to beverydifficultinsuchsituations. Withtheaidofthesubsequentlyfab- ricated plaster model (Fig. 2), it was quiteeasytotaketheopticalimpres- sionforfabricatingtheCERECcrown. The BRILLIANT Crios bloc used for milling the full crown is shown on thephoto(Fig.3,shadeA2HT). Atthetimeofpreparingthisreport, there were only two milling pro- grammes available from other man- ufacturers for processing composite blocs in the CEREC system. In future, there will be an own COLTENE BRIL- LIANT Crios milling programme by theSironacompanyavailableforuse intheCADsoftware.* Inourcasewechosetheprogramme GC Cerasmart 14. Presently, the Crios bloc can be milled with this Sirona programme. (A further possible programme is the 3M ESPE Lava Ul- timate). The bloc available to us was size14,infutureablocsize12willalso beavailable. Construction and milling of the crown leads to the following result (Fig. 4). Compared with ceramic ma- terials,forexampleIPSEmpress(Ivo- clar Vivadent), the surface structure of the ground crown appears very smoothandtheresiduallugissmall- er after milling. This facilitates its re- moval with a diamond and nothing remains visible after brief polishing. Polishing can be performed after milling using a conventional rotary polisher or milling paste. The crown in question also passed the check for cracksormaterialchipping. A check of the precision fit on the plaster model was good (Figs. 5 + 7), so that we decided to try-in and then placetherestorationonthepatient. To ensure bonding between the mounting material and the milled restoration, use ONE COAT 7 UNI- VERSAL bond (COLTENE) only. An etching step with hydrofluoric acid isnotnecessary. ONE COAT 7 UNIVERSAL was ap- plied to the sandblasted and cleaned mounting area of the restoration and rubbed in for 20 seconds (Fig. 6). Excess adhesive was removed with oil-free compressed air for 5 seconds. Bondingtothetoothsubstanceand/ or composite can be carried out us- ing a suitable adhesive. ONE COAT 7 UNIVERSAL Bond is recommended here (procedure according instruc- tions for use). We used this adhesive throughoutinourcase. Prior etching of the enamel areas withphosphoricacidisrecommend- ed and was carried out by us. For bonding of the restoration, a dual- curing resin cement, i.e. DuoCem™ (COLTENE),oralight-curingcompos- itecanbeused. The BRILLIANT Crios crown is now ready for insertion. After bond- ing our full crown with DuoCem™ (COLTENE), the edges were cleaned, excess was removed, and then every surface of the restoration was light- cured for 30 seconds (light output > 800m W/cm2) and then worked on with a rubber polisher. Milling of the occlusion proved simple and quick. The gloss of the entire composite crown already appeared after a short time. Furthermore, when readjust- ing the occlusal contact points, we were able to polish immediately, which is much more difficult to do with ceramic, and in particular, with firedcrowns. CAD/CAM restorations made from the new Crios blocs can be charac- terised, modified or also repaired at anytime.Modificationscanbemade directly without prior treatment. In case of intraoral repairs, the restora- tion surface is cleaned with cleaning paste, and then roughened using a diamond rotary instrument. In both cases, ONE COAT 7 UNIVERSAL is applied to the surface to be treated and cleaned with compressed air for 5 seconds. This is followed by light-curing for 10 seconds (also see instructions for use ONE COAT 7 UNIVERSAL). Colour shades or com- posite (i.e. BRILLIANT Ever-Glow, COLTENE) are then used afterwards according to the respective manu- facturer's instructions. The mate- rial discussed for the fabrication of a CEREC crown is a composite with the following technical features. The flexural strength and the modulus of elasticity are represented in the followinggraphs.** For comparison purposes, the ce- ramic and composite materials of other manufacturers were used. The good flexural strength and the e- modulus,whichissimilartodentine, make the material more elastic than ceramic. Conclusion Handlingisconvenientlysimpleand the clinical result after placement and 4 weeks later is very good (Figs. 8 + 9). The following points result in time saving and "service benefits" versusceramicrestorations: -Nofiringoftherestorationrequired (i.e.aswithIPSe.maxCAD). - Gloss of the composite is easy to achieve, also much easier than with IPSEmpressCAD. - No etching with hydrofluoric acid orsilanisationnecessary. - If required, repairs with composite are easy to realise, analogue to a fill- ing. - Dentin like e-modulus, less brittle- nessthanceramic. Long-term studies are necessary to compare the clinical results with ce- ramic materials. In terms of applica- tion, this material proved excellent. The patient was very satisfied with the result and praised the pleasant wear comfort of the composite res- toration versus his previous ceramic crown immediately after treatment. Next, we would like to attempt res- toration of an implant with a single crown. Fig.1:Initialsituation,singleX-rayoftooth37withexist- ingroot fillingandabutment post Fig. 7:The finished BRILLIANT Crios crown on the plaster modelinocclusion ** " Comparison of filler morphology, mechanical strength and milling characteristics of different CAD/CAM blocs for Sirona inLab MC XL milling system " Cornelia Kopfmann, Ralf Böhner, Coltène/Whaledent AG, Switzerland . David Zweifel, Private Dental Laboratory, Switzerland Fig. 4: Milled crown with residual lug (separation point frombloc) Fig.2:Plastermodelwithprepared toothstump37 Fig.8:Clinicalsituationafterplacement andpolishing Fig.5:Crioscrownonplastermodel Fig.3:MillingblocBRILLIANTCrios,colourshadeA2HT Fig.9:Follow-upafter4weeks Fig. 6: ONE COAT 7 UNIVERSAL is applied to the bonding surface of the crown and rubbed in with a dental brush for20s. Dr.Med.Dent. ChristophHüskens Herrenwiese3 9306Freidorf/TG Tel.:+41714500670 Fax:+41714500672

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