logo 18 • CAMLOG Partner Magazine • July 2018 23 Due to the patient's wish for a definitive restoration as quickly as possible, the patient was recommended to have a fixed screw-retained implant solution on five implants. An occlusally screw-retained allresin temporary bridge was to be inserted immediately after surgery. In the context of early loading, a definitive, occlusally screw-retained resin-veneered bridge with metal framework was to be inserted after approximately 14 days of removing the sutures. Preparation of the prosthetic surgical treatment (session 1 following the decision on therapy) Initially, models in the centric condylar position (RCP) were required. For this purpose, the maxillary prosthesis was duplicated in a crystal-clear individual tray in the practice's own laboratory. After designing the margins this was used for taking a relining impression to fabricate the upper jaw master cast on which the new full maxillary prosthesis was to be fabricated. At the same time, an anterior tooth jig for RCP occlusion could be attached to the maxillary incisors of this transparent prosthesis. RCP occlusion was performed with GC-Bite Compound. Together with a mandibular alginate impression, this made it possible to assemble articulated models in RCP after the first treatment session (without wax wall fabrication and a further treatment appointment). Esthetic try-in (session 2 following the decision on therapy) For esthetic and functional reasons, the upper jaw must first be ideally planned by means of wax-up, mock-up and/or wax setup (Fig. 5). For this reason, the maxillary prosthesis was placed on the maxillary master model according to functional and esthetic criteria. After wax try-in and checking static and dynamic occlusion (canine guidance), minimal esthetic corrections were made. Now the individual impression and bite registration tray for the surgical procedure could be fabricated (Fig. 6). Preimplantation measures in the laboratory In the laboratory, the lower teeth of the situation model were removed. The lower jaw was set up versus the new maxillary wax-up. The finished maxillary prosthesis was additionally duplicated in a transparent prosthesis. Both prostheses therefore fit the same maxillary master cast. Then the individual impression/bite registration tray was fabricated. This corresponded to a duplicated mandibular prosthesis (see Fig. 6) with • extended saddles (snowshoe principle) in regions 36 to 38 and 46 to 48, • three deep colored bites in region 36, 31/41 and 46 as well as • two chimneys in region 35 to 31 and 41 to 45 for the open impression of the implants. The deep colored bites were designed such, that they could be securely encrypted with the maxillary transparent prosthesis during bite registration. The snowshoe saddles in regions 38 to 36 and 46 to 48 serve only as a vertical stop for when the patient bites during simultaneous impression taking and bite registration. The COMFOUR® Titanium caps were coated with plastic in the laboratory for subsequent splinting in the mouth and the correspondingly long screws for the open impression were selected on the basis of the masticatory plane. Day of surgery (session 3 following the decision on therapy) The surgical procedure was performed under intravenous sedation with Dormicum. First, the teeth were extracted and a full flap with distal relief incisions was prepared in regions 36 and 46. The alveolar bone was flattened to obtain a jaw bone width corresponding to the implant diameter. The enlargement of the loading polygon was achieved by the oblique (30 degrees) insertion (Fig. 7) of the two distal implants in regions 35 and 45 in the specified window of Fig. 4: The bone height above the mental foramen was more than six millimeters. Fig. 5: Wax-up of the complete maxillary prosthesis to improve esthetics and function. Fig. 6: The individual impression and bite registration tray created according to the snowshoe principle. CASE STUDY Fig. 7: Insertion of the distal implant in region 45/46 at an angle of 30°.
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