Implants

40 I I industry report _ Full arch rehabilitation implants1_2012 the soft tissues. Abutment diameters are therefore independent of implant diameters, which means that any implant may host the four different abutment emergence profiles. The different emergence profiles start from the 2mm, 2.5mm or 3mm posts, placed at crestal bone level. The geometry of the abut- ments provides for platform switching even at a prosthetic level, which is of vital impor- tance in the organisation of the connecting tissue and the epithelial layer. The supraperiosteal space involved in the shift from the connecting post diameter (2–3mm) to the diameter of the abutment hemisphere (3–6.5mm), allows a thicker and denser connecting tissue to form, resulting in the optimal preservation of the papilla. In thefollowingcase,alltheselectedabutments have a 3mm post, as they must connect to the 3mm wells of the 5.0 x 6.0mm implants. Abutment post heights, inclinations and di- ameters are selected in the laboratory in ac- cordance with the position of the implants relative to the anatomy of the alveolar ridge. Trinia is a CAD/CAM multidirectional fibre reinforced resin material, which despite its light weight is capable of withstanding oc- clusal forces. _Case report A 52-year-old male patient, presenting a severely compromised mandibular bone, was treated with the placement of four short implants. Two SHORT® implants (4.5 x 8mm) were placed bilaterally at the canine region and two ULTRA SHORT® implants (4 x 5mm) were bilaterally located at the first molar re- gion(Fig1).Theimplantswereplacedinatwo- stage surgery and they were uncovered after a healing period of three months (Figs 2&3). Clinically, the prosthetic treatment be- gan with an implant level transfer impres- sion by inserting with only finger pressure a green impression post with its corresponding acrylic sleeve into the 3.0mm implant well, prior to recording their position by mak- ing an implant level impression with any conventional impression material (Fig 4). Upon the removal of the full arch impres- sion, green impression posts were removed from the implant wells and inserted into an implant analogue of the same colour be- fore inserting them into their correspond- ing acrylic sleeves within the impression. Prior to the pouring of a stone model, a resilient acrylic was applied around the im- pression posts to simulate a soft tissue con- tour in the stone model. The stone model was used for the fabrication of a wax bite rim to record the occlusal registrations. After articulation of the models, appropriate abut- ments with the largest practical hemispheri- cal base were selected and inserted into their corresponding implant analogues within the stonemodel.Theirprostheticpostswerethen milled parallel to one another (Fig 5). The model with the milled abutments was used to fabricate a light cured resin bar and denture tooth set up for an intra-oral con- firmation of the arranged teeth. Once the denture set-up had been clinically approved, a facial occlusal silicone mask was initially formed over the denture wax set up. Prior to formingthelingualsiliconemask,indexingor alignment grooves were placed in the facial occlusal mask. After fabrication of the lingual mask, grooves were cut into the stone model to prevent the subsequent entrapment of air, when acrylic was poured into the silicone flask through anterior cut-away or aperture in the lingual mask. Prior to the removal of the wax denture tooth set up from the stone model, the facial lingual extent of the wax denture tooth set up on the alveolar ridge wasmarkedonthestonemodelwithapencil. After the removal of the denture teeth and wax from the resin bar, the teeth were cleaned and lingually roughened or modified prior to being facially glued to the facial oc- clusal silicone mask with cyanoacrylate glue. An uneven thin application of clear resin was Fig 12