Please activate JavaScript!
Please install Adobe Flash Player, click here for download

implants - international magazine of oral implantology International Edition

industry report I porary crown was fabricated for tooth 22 (Fig. 20). The marginal gingiva in the region of the implant had to be moved slightly in an apical direction with the definitive restoration owing to the excess tis- sue. _Fabrication of abutments and final crowns Using super-hard plaster, the dental technician fabricatedroot-shaped(conical)stumpstoprevent rotation. These were placed in the impression to fabricate the master model and extended with wax pins (Figs. 21–23). A new wax-up was prepared based on the updated aesthetic analysis and the outer cervical contour of the implant restoration wastransferredtothemodel(Fig.24).Theanatom- ical shape of the emergence profile was then cre- atedwithafinemillingmachine.Theimplantcrown was thus given a natural emergence contour. The papillae were slightly sharpened and smoothed to give an optimal gingival contour. The optimised shapeofthepapillaeavoidedconcavitiesoccurring laterinthecervical,slightlysubgingivalceramicar- eas, which are difficult to clean and can lead to irri- tation of the gingiva (Fig. 25). The wax-up was fit- ted with a pin at the implant position, which en- gagedwiththeimplantinterfaceforbetterfixation of the wax-up during try-in (Fig. 26). A suitable abutment was selected from the CONELOG Esthomic abutment set and the silicone indexes based on the wax-up. In this case, the CONELOG Titanium base CAD/CAM was too low owing to the apical position of the implant shoul- der. Therefore, the dental technician decided on a considerably longer, straight CONELOG Esthomic abutment, which was customised for use as a tita- nium bonding base (Figs. 27–29). He modelled a secondary abutment with wax on the customised titaniumbase (primary abutment),whichwas tobe fabricated from zirconium oxide. Subsequent bondingwiththetitaniumbaseresultedinahybrid abutment with full anatomical contours, both in the palatally and subgingivally positioned emer- gence area through the soft tissue. Room was left on the buccally visible area for a pressed ceramic veneertobefixedbybonding(Fig.30).Usingadou- ble scan, the dental technician imported the 3-D shape of the primary abutment and the wax model of the secondary abutment into the planning soft- ware (Abutment Designer, 3Shape; Fig. 30). Then the secondary abutment was ground from zirconiumoxideceramicwithCAMtechnologyand immersed unsintered into a fluorescent solution (Fig. 31). The screw channel was prepared prior to sintering. As zirconium oxide cannot be etched, the dentaltechnicianhadtofireathinlayerofetchable, highly fluorescent zirconium oxide veneer ceramic on to the buccal surface and preparation margin of the hybrid abutment prior to modelling the cap for the pressed ceramic veneer (Fig. 32). Fluorescence ensures the transmission of light in the gingival area. This has a positive effect, particularly in the case of a thin gingiva. Then, the dental technician Fig. 34_Modelling of the mamelon for the implant-supported veneer from a palatal view. Fig. 35_After glaze firing and polishing, the natural anatomy and surface characteristics of the restoration were checked. Fig. 36_Aesthetic try-in: The patient and her dental technician, Andreas Nolte, appreciating the highly successful outcome and nearly completed treatment. Fig. 37_The pressed ceramic veneer was mounted on the previously bonded hybrid abutment by bonding with dual-curing composite. Fig. 38_The transitions between the abutment and the veneer were smoothed and polished to a high gloss with a brush and polishing paste. Fig. 39_The implant restoration is screw-retained. For biomechanical reasons, the screw access channel was placed in the zirconium oxide section. I 29implants1_2014 Fig. 34 Fig. 36Fig. 35 Fig. 37 Fig. 39Fig. 38