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7Dental Tribune Middle East & Africa Edition | September - October 2013 media cme are complete, the file is “nested” or positioned in the zirconia disk (Figs. 10, 11) and milled to a full contour approximately 30 percent larger than the final restoration. Once the resto- ration is milled and removed from the disk, it is dipped in the appropri- ate coloring solution and sintered in an oven for 6.5 hours at 1,530 degrees Celsius where it shrinks to its final size. I requested that Oral Arts e-mail me the initial design for my approval before milling (Fig. 7). The case met my expectations on design and we proceeded with fabrication. On lar- ge complex cases, I enjoy the option of approving digital case design via e-mail before case completion. After the bridge framework was sintered and checked for accuracy of fit and margins (Fig. 8), IPS e.max Ceram was stacked and baked onto the facial surfaces for enhanced esthetics. IPS e.max Ceram is a stackable ceramic powder within the IPS e.max system. The veneering ceramic is the key to highly esthetic results, both on lithi- um disilicate and on zirconium oxide (Fig. 9). The veneer was then waxed to a cut- back shape with mamelons, invested, burned out using the lost wax tech- nique and pressed using IPS e.max Press lithium disilicate. Once the ve- neer was divested, it was layered using IPS e.max Ceram to further improve esthetics. Final delivery and cementation One of the challenges of cementing a case like this is the fact there are two dental materials side by side. Tooth #7 has an IPS e.max veneer and teeth #8 and #9 will be BruxZir with porcelain facials. IPS e.max is more translucent than the BruxZir, thus allowing more visibility of the cement and tooth that is prepped. The cement chosen for the bridge was Panavia SA Cement, a self-adhesive resin. I choose a self- adhesive resin cement for the bridge because it has ease of use in that it can be light cu- red, but if the light doesn’t penetrate the zirconia completely it will auto cure. This gives strength but also keeps the cementing process simple; it also would work on a full crown made of IPS e.max. The cement for the veneer was Clear- fil Esthetic Cement EX, a resin ce- ment. Veneer preps do not have a re- tentive and resistant form. The veneer needs to have the maximum strength that resin bonding can give. I can get light though the veneer to fully cure the cement so an auto-cure option is unnecessary. Clearfil Esthetic Ce- ment EX is one of the strongest bonds available and will work excellently on this veneer or a full crown made from IPS e.max. Both restorations, the veneer and bridge, were tried in and contacts and occlusion checked. The colors were very close to exact between the two restorations. Clearfil Esthetic Ce- ment EX comes with try-in paste, so we used the try-in paste and found that Universal colored try-in paste on both the bridge and veneer made a perfect match. K-etchant gel was used to clean both restorations; the abutments were cleaned using a prophy cup and sim- ple flour pumice with no fluoride. Panavia SA Cement was placed in the bridge abutments and the bridge was placed on the teeth. There is no need for a silinating agent on Brux- Zir because Panavia SA Cement will bond to the zirconia. Then it was light cured in place and the excess cement cleaned off. An advantage to this type of cement is that it gives the benefits of resin bonding, and if you can’t get the cu- ring light to the cement through the material it will auto cure in five minu- tes on its own, thus giving the benefit of a resin cement but the ease of use of a glass ionomer. The veneer was treated with ceramic primer before resin bonding using Clearfil Esthetic cement in the Universal shade and light cured, then the excess cement was cleaned up. The bottom line In 2011, many labs reported the number of metal-free restorations surpassed the number of porcelain -fused-to-metal restorations for the first time. Most of these metal-free restorations are full-contour zirco- nia and lithium disilicate. Porcelain -fused-to-metal restorations have reigned as the predominant tooth- colored, indirect restorations for 50 years, so they have a long, successful history. On the other hand, BruxZir has a much shorter history and most labs have only had it available for less than four years. The demand on the dentist to place esthetic restorations that are strong and will last has lead to BruxZir’s large market share. Lear- ning new ways to employ this ma- terial is a must, and new innovative techniques can evolve to meet our patients’ demands. References is available from the author. mcme selF instruction ProGram CAPP with Dental Tribune with its mCME- Self Instruction Program gives you the opportunity to have a quick and easy way to meet your continuing education needs. mCME offers you the flexibility to work at your own pace through the material from any location at any time. The content is international, drawn from the upper echelon of dental medicine, but also presents a regional outlook in terms of perspective and subject matter. Membership: Take membership for one year by subscription for the newspaper: 600 AED Take article with one newspaper subscription: 100 AED per issue. After the payment, you will receive your membership number and will be able to start the program. 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The answers and critiques published herein have been checked carefully and represent authoritative opinions about the questions concerned. Articles are available in www.cappmea.com after the publication.For more information please contact events@cappmea.com or +971 4 3616174 For interaction WitH tHe Writers Find tHe contact detail at tHe end oF eacH article. Mark McOmie, DMD, attended the University of Utah. While attend- ing the university he worked as a lab technician for several years. He then furthered his education at the Uni- versity of Louisville School Of Den- tistry, graduating and entering pri- vate practice in 1998. McOmie has presented research at the Kentucky Dental Association, International Association of Dental Research and American Association of Dental Re- search. He is a member of the Ten- nessee Valley Dental Study Group, Chattanooga Area Dental Society, Tennessee Dental Association, and the American Dental Association. McOmie also has hospital privileges at Memorial Hospital, where he rou- tinely presents lectures on dentistry. You may contact him at markmcomie@gmail.com. Contact Information Fig.7: The screen shot of the design from Oral Arts Dental Lab in Huntsville,Ala. Fig.8: Full-contour zirconia cut-back to allow porcelain on the facial to increase esthetics. Fig.9: Porcelain facial applied to the BruxZir. Fig.10: Layout of crowns on a design computer to be milled in BruxZir. Fig.11: BruxZir disc with the crowns “nested” and fully milled.