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Purpose: To evaluate the success and survival of immediately placed tapered implants to support fixed restorations in the maxilla and mandible., Materials and Methods: The study was a prospective, multicenter, non-interventional study of patients requiring tooth extraction who requested an implant-supported restoration in the maxilla or mandible. Patients received at least one tapered implant (either immediately after tooth extraction or at a later time point). Abutments were placed 42 to 56 days after surgery, and prostheses were placed after a further 14 days. Treatment and implant success were the primary effectiveness criteria, and secondary parameters included radiographic bone loss, patient satisfaction, and gingival health., Results: A total of 436 patients were enrolled, of whom 376 were included in the safety analysis. Single implants were placed in 77% of patients, two implants in 16%, and three or more implants in the remainder. The cumulative implant survival rates for immediately placed implants were 98.3% after 1 year and 97.7% from 2 to 5 years. Patient satisfaction was good or excellent in most patients and the majority of implants showed no or < 1-mm change in bone level for up to 5 years., Conclusions: The survival rate of immediately placed tapered implants was comparable to that found in other studies. Immediate implant placement with tapered implants can allow rapid rehabilitation with no adverse impact on implant survival.

Purpose: Inadvertent perforation of the sinus membrane is a frequent complication encountered during sinus floor elevation (SFE). Different strategies have been described for the prevention or treatment of perforations, with varying results. This paper reports the findings of a preliminary study into the application of a novel nasal suction technique in which negative antral air pressure was used to facilitate the raising of the sinus lining and to reduce the risk of perforations occurring during SFE., Materials and Methods: In 24 consecutive patients, nasal suction was applied through the ipsilateral nostril during SFE. The suction device was attached to a high-flow vacuum regulator that incorporated a suction canister connected to a -10-kPA medical vacuum (-75 mm Hg). Fifteen subjects received unilateral SFE, and six subjects had bilateral staged lateral wall sinus elevation; the remaining three subjects had osteotome sinus floor elevation (three unilateral and one bilateral) with simultaneous implant placement., Results: During SFE, the use of nasal suction facilitated the inversion of the sinus lining around the edges of the lateral access window. This made the sinus lifting easier, as the need for extensive instrumentation was significantly reduced. In three subjects, elevation of the sinus lining occurred spontaneously from the lateral, medial, and inferior surfaces of the antrum when nasal suction was applied., Conclusion: Sinus lifting was facilitated by nasal suction. No perforation of the sinus lining occurred in this series. Controlled clinical trials are being designed to further demonstrate the clinical efficacy of the nasal suction technique in SFE.

Purpose: The purpose of this study was to derive alternative implant shapes which could minimize the stress concentration at the shoulder level of the implant., Materials and Methods: A topological shape optimization technique (soft kill option), which mimics biological growth, was used in conjunction with the finite element (FE) method to optimize the shape of a dental implant under loads. Shape optimization of the implant was carried out using a 2-dimensional (2D) FE model of the mandible. Three-dimensional (3D) FE analyses were then performed to verify the reduction of peak stresses in the optimized design., Results: Some of the designs formulated using optimization resembled the shape of a natural tooth. Guided by the results of the optimization, alternative implant designs with a taper and a larger crestal radius at the shoulder were derived. Subsequent FE analyses indicated that the peak stresses of these optimized implants under both axial and oblique loads were significantly lower than those observed around a model of commercially available dental implant., Conclusion: The new implant shapes obtained using FE-based shape optimization techniques can potentially increase the success of dental implants due to the reduced stress concentration at the bone-implant interface.