Effects of implant angulation, impression material, and variation in arch curvature width on implant transfer model accuracy.

PURPOSE: The effects of implant angulation, impression material, and variation in width of the arch curvature on transfer models were evaluated. MATERIALS AND METHODS: Three edentulous maxillary epoxy resin models were fabricated, and six internal-connection implant analogs were placed in different locations and different angulations in each model. In the first model, implants were positioned in the canine, first premolar, and first molar regions, and all analogs were positioned parallel to each other and perpendicular to the horizontal crestal plane (parallel model). In the second model, analogs were positioned in same regions (canine, first premolar, and first molar), but three of them were positioned with 10-degree buccal angulations (versus the horizontal crestal plane) (angular model). In the third model, analogs were inserted in the lateral incisor, canine, and second molar regions and parallel to each other (wide-arch model). Eighteen impressions of each model were made with each of the three materials--condensation silicone, polyvinyl siloxane, and polyether--and impressions were poured and kept at room temperature for 24 hours. They were then observed under a toolmaker's microscope, with epoxy resin models of each group used as references. Distance deformations between implants in each model in the x- and y-axes were recorded separately. Implant angulation deformations were recorded in the x-z plane. Statistical evaluations were performed with analysis of variance and the least significant difference post hoc test. RESULTS: Angular model measurements showed the greatest deformation values (P < .05). All impression materials showed deformation, and the polyether impression models showed statistically significantly less deformation in angular measurements (P < .05). CONCLUSIONS: The models with implants placed parallel to each other exhibited greater accuracy than a model with implants placed at angles to each other.

Rehabilitation of maxillary anterior esthetics by alveolar distraction osteogenesis with immediate implant placement: a case report.

Esthetic reconstruction of severe soft and hard tissue deficiencies is the utmost challenge in implant dentistry. To prevent postoperative bone resorption and to control the amount of hard and soft tissue volume, distraction osteogenesis followed by immediate implant placement has been proven to be a promising combined technique. The aim of this report is to introduce a treatment strategy to maintain anterior esthetics and to control hard and soft tissue volume in a case, treated with the combined technique of vertical alveolar distraction and immediate implant placement. An osteotomy was performed by the use of an oscillating saw. Cut alveolar segment was mobilized, and a distractor device was inserted in between the segments. During the activation and consolidation periods of distraction, anterior esthetics was provided with removable acrylic provisional crowns placed on the distractor's rod. In 2 weeks of distraction period, vertically 10 mm of new bony segment was obtained, and 2 weeks after the removal of distractor, maxillary incisors were extracted. Four dental implants were placed according to the immediate placement protocol. In osseointegration period, provisional restorations were fabricated on abutments to form harmonious gingival contours and to maintain maxillary anterior esthetics until the fabrication of final restorations.

Effects of Bartter's syndrome on dentition and dental treatment: a clinical report.

Bartter's syndrome is an autosomal recessive form of severe volume depletion due to renal salt wasting. This clinical report describes the prosthodontic treatment for a 24-year-old man who suffers from Bartter's syndrome. The treatment plan included endodontic treatment of the maxillary anterior incisors and placement of cast dowel-and-core restorations because of reduced crown height. The patient's remaining teeth were restored with metal-ceramic crowns.