CD0412

CE article _ mastering occlusal function I _Case 1 A 45-year-old female presented with two por- celain-fused-to-metalcrownswithrecurrentcaries on tooth numbers 14 and 15. They were estimated to be about five years old. Her chief complaint was thatitwasdifficulttoflossbetweenthem.Clinically, the crowns had very tight interproximal contacts and closed embrasures. Dental floss was nearly im- possible to penetrate through the contact, and re- current caries subsequently developed (Fig. 11). The crowns were removed, core build-ups completed, and the intraoral scans taken: _Preparation quadrant (upper left); _Opposing quadrant (lower left); _Buccal bite images. The models within the CEREC Software 4.0 were articulated,andtheBiogenericcalculationwascom- pleted for the two teeth. Because the interproximal contacts were of utmost concern for the patient, both designs were manipulated at the same time to achieve better contact strength and embrasure shape. The interproximal contact between 13 and 14 was designed to mimic the same shape between 12 and13.TheinitialBiogenericproposalfor#15placed themesialportionintothedistalof#14(Figs.12,13). Right-clicking the proposal brought up the myriad of tools to adjust the proposal (Fig. 14). A tool was selectedthatwouldrepositionjustthemesialportion of #15. It could then be repositioned in any direction (Figs. 15, 16). It was simply moved distally. A broader contactwasestablishedbetweenthetwodesigns,but with better embrasures than the prior crowns. Minor customizationoftheocclusalschemewasthendone. ThedigitalcrownsweremilledwithCEREC’sMCXL milling chamber out of IPS e.max CAD blocks (Ivoclar Vivadent). Each crown milled in roughly 10 minutes Fig. 12_The initial proposals for 14 and 15 were excellent; however, 15 encroached into 14. Fig. 13_A design tool wheel emerges when right-clicking on the design. Fig. 14_The mesial portion of 15 was selected for movement. Fig. 15_The mesial portion was moved into the appropriate position. I 09cosmeticdentistry 4_2012 Fig. 12 Fig. 13 Fig. 14 Fig. 15