Implants

33 research_ Impression and registration I implants1_2013 rected (Fig 1a). The resulting denture was used by the patient until the final restora- tion was delivered. For the final restoration of the maxilla, an implant-retained denture with telescopic crowns as attachments was planned. Aftertheimplantwasuncovered,theden- ture was modified to allow sufficient space for the healing abutments. A duplicate of the denture (DentDu) was made out of clear resin (Paladur, Heraeus, Hanau, Germany, Fig 1b). A trial of the DentDu was performed and minor occlusal discrepancies were cor- rected (Fig. 1c). Bite records were taken in centric occlusion with modelling resin (pat- tern resin®, GC, Alsip, IL; Fig. 1c), using the casts of the original denture. Afterwards, the DentDu was placed in an articulator and a controlling of the occlusion was made (Fig 2a) with the bite records. A pickup transfer system consisting of a titanium impression post and a plastic impression sleeve was employed (Dentegris, Duisburg, Germany, Fig 2b). The DentDu was carefully modified by creating internal clearance in the area of the implants so that it could be applied as an individualised custom tray. This permit- ted it to be fully seated when the impression posts were in place. Impressions were gen- erated by a polyether material (Impregum, 3M ESPE, St. Paul, MI). During this process, the DentDu was kept in centric occlusion using the bite records (Fig 3a). The titanium impression posts were con- nected with the implant analogues and with the plastic impression sleeves (Dentegris), which were embedded in 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). Customisable abutments (Dentegris) were taken to fabricate the implant abut- ments. Parallelism, angulation, position and shape of the implant abutments were determined using a silicon key fabricated from a matrix of C-silicone (Zeta - labor, Zhermack SpA, Badia Polesine, Italy, Fig 5). The dentist and the dental technician relied on two alternatives for customised abutments selection: 1) UCLA customis- able abutments (UCLA, Dentegris) for cast- ing with a gold alloy (for example, Portadur P4, Au 68.50 per cent, Wieland, Pforzheim, Germany, Fig 6a) or 2) platinum - iridium custoiable abutments (PTIR, Dentegris) for- Fig.3a Fig.3b Fig.3c Fig. 4a Fig. 4b Fig. 5 Fig. 6a Fig. 6b Fig. 3a_Taking the impression with the DentDu. The bite records were used to determine the exact position. Fig. 3b_Fabrication of the master cast Fig. 3c_Placement of the cast into the articulator using the bite registrations 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