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ePaper created 2015-03-06, 14:42:46 | version 1.33.01
20 I I CE article _ biomechanical principles orientation of the preparation model was per- formed (Fig. 26d). Orientation is for optimal design, not path of insertion. The margins were then traced andviewedinICEmode,whichprovidesarendering of the scanned images for a clear view of the margins, teeth and tissues (Figs. 26e, f). The initial proposals for the restorations were made using Library A and autogenesis, which is morphogenesis of the library tooth with the neigh- bouring teeth (Figs. 26g–i). Material thickness of the proposed restorations was checked (Fig. 26j, k). Tools were then utilized to improve the initial proposal to the desired result. The rubber tooth tool was used to make minor ad- justments to the anatomy (Figs. 26l–n). The smooth surface tool was used to smooth the surfaces (Figs. 26o, p). The location and strength of the occlusal con- tacts were checked and adjusted (Fig. 26q). Inter- proximal contact strength and location was then verified and adjusted as needed (Fig. 26r). The final proposals were then verified prior to milling(Figs.26s,t,w).Thesliceplaneviewwasused to check the space between the tooth preparation and the restoration (Figs. 26u, v). This is done to check for possible areas that may prevent the final restoration from completely seat- ing on the preparation or for areas that may be over milled. Over-milling reduces the thickness of the material.Thisviewalsoillustratesthelackofprepa- ration on the axial wall and the minimally invasive approach taken. The location of the sprues were notedandadjustedasneededinthemillingpreview (Fig. 26x). The fit of the restorations was then verified intraorally prior to final seating (Figs. 26y, z). Oc- clusion can be verified intraorally with e.Max CAD priortocrystallizationandanystainingandglazing. Checking occlusion with Empress CAD blocks prior to bonding in place is not recommended. The restoration for #3 was then glazed and crystallized in a Programmat CS2 furnace (Ivoclar Vivadent). The restoration was allowed to cool to room temperature upon completion of glazing and crystallization. The restoration was then cleaned with a steam cleaner. Five percent hydrofluoric acid was used to etch the e.max restoration for 60seconds.TheEmpressrestorationwasetchedfor 20 seconds. The etchant was rinsed with a steam cleaner. Ivoclean(IvoclarVivadent)wasappliedfor20seconds onbothrestorationstocleantheirinternalsurfaces. Monobond Plus primer (Ivoclar Vivadent) was ap- plied to the internal surface of the restorations for 60 seconds. The primer was lightly air dried after 60 seconds, taking extra care not to allow primer on the outside surfaces of the restorations. The teeth were isolated using Isolite (Fig. 27). Multilink Primer A/B was scrubbed onto the entire bonding surfaces using a microbrush for 30 sec- onds. Excess material was dispersed with blown air until the mobile liquid film was no longer visible, leaving a glossy appearing surface (Figs. 28 & 29). An OptraStick Application Aid (Ivoclar Vivadent) was used to seat the restorations on the teeth because onlays and partial crowns can be difficult to handle. Initial tack curing was completed using aBluephasecuringlight(IvoclarVivadent)forthree seconds at each interproximal area. The resin was then removed easily using a 36/37 scaler from Brasseler. Liquid Strip (Ivoclar Vivadent), a glycerine gel that prevents an oxygen-inhibited layer of the resin cement, was applied to the margins prior to final curing (Figs. 30 & 31). Final curing of the restorations was then com- pleted (Fig. 32). The initial #00 cords were removed Fig. 34_Polishing. Figs. 35a & b_Final restorations occlusal view. CAD/CAM 1_2015 Fig. 35a Fig. 35bFig. 34 CAD0115_12-21_Young 02.03.15 12:39 Seite 9 CAD0115_12-21_Young 02.03.1512:39 Seite 9