implants - international magazine of oral implantology

I research the impression material (Fig. 3b). A master cast was then fabricated and articulated with the help of the bite records (Fig. 3c, Figs. 4a & 4b). Customizable abutments (Dentegris) were taken to fabricate the implant abutments. Parallelism, an- gulation, position and shape of the implant abut- ments were determined using a silicon key fabri- cated from a matrix of C-silicone (Zetalabor, Zher- mack SpA, Badia Polesine, Italy, Fig. 5). The dentist and the dental technician relied on two alternatives for customized abutments selection: 1) UCLA cus- tomizable abutments (UCLA, Dentegris) for casting withagoldalloy(forexample,PortadurP4,Au68.50 %, Wieland, Pforzheim, Germany, Fig. 6a) or 2) plat- inum-iridium customizable abutments (PTIR, Den- tegris)forcastingwithachromiumcobalt(CrCo)al- loy (for example, Ankatit, Anka Guss, Waldaschaff, Germany, Fig. 6b). After casting, the customized implant abutments weregrinded,polishedandservedasthe basisforthe fabrication of electroformed pure-gold copings with a thickness of 0.25 mm (AGC Galvanogold, Au > 99.9%, Wieland, Fig. 6c).2-4 The framework was then constructed via CAD/CAM. To ensure proper func- tioning of the framework, a plastic mock-up and a temporary fixed denture (TFD) were milled (ZENO- PMMA,Wieland).Thecustomizedimplantabutments, the electroformed copings, the mock-up and the TFD were delivered by the dental laboratory for the next clinical session. Theabutmentsweretransferred,positionedonthe implants and torqued to 35 Nm using a resin transfer key (pattern resin, GC; Figs. 7a-b). From this point on, thecustomizedabutmentsremainedfixedinorderto avoid any possible inaccuracies. The electroformed copings were placed on the implant abutments (Fig. 7c). The mock-up was placed over the electroformed copings and the occlusion was checked with the bite records (Figs. 8a-b). A final impression with a poly- ether impression material (Impregum, 3M ESPE) was taken with electroformed copings. The mock-up was further set up and used for the fabrication of a new (final) master cast. After the impression was taken, the TFD was fixed on the implant abutments using temporary cement (TempBond, Kerr, Orange, CA). It was then left in place until the delivery of the final restoration (Fig. 8c). Thenewmastercastwasarticulatedwiththehelp of the gold copings and the mock-up. The metal framework was milled (here: Titanium Zenotec TI, Wieland,Fig.9a).Theveneeringofthesuperstructure was made using a light-cured indirect ceramic poly- mer (Ceramage, SHOFU, Menlo Park, CA, Figs. 9a-d). The electroformed gold copings were fixed in the metal framework using a self-curing compomer ce- ment (AGC Cem, Wieland, Fig. 10). The above-described procedures can be also per- formedincasesinwhichafixeddenturewasplanned for the rehabilitation of the full-arch (Figs. 11a & 11b, Figs. 12a-c) and in cases where part of the natural dentitionisperiodontallystableandcanbeappliedas abutments.Inthesecases,theimmediatefulldenture can be designed as a cover denture. From this cover 14 I implants3_2012 Fig. 6a Fig. 6b Fig. 6c Fig. 4b Fig. 5 Fig. 4a Fig. 7a Fig. 7b Fig. 7c Fig. 4a_Master cast. Fig. 4b_The master cast is placed into the articulator. Fig. 5_The customized implant abutments are fabricated using a matrix of C-silicone. Fig. 6a_Gold customized abutments. Fig. 6b_Chromium cobalt (CrCo) customized abutments. Fig. 6c_Electroformed gold copings. Figs. 7a & 7b_The customized abutments are mounted on the implants using a transfer key. Fig. 7c_Electroformed gold copings in situ.