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摘要
Purpose: The aim of this study was to evaluate the fit and mechanical stability of conventional versus passive fitting 3-unit fixed dental prosthesis (FDP) screw-retained on implants. Methods: Twenty acrylic models, each with two embedded implants, were fabricated and functioned as patient-models. Impressions were taken and 20 all-ceramic FDPs were prefabricated on the plaster casts. Respectively 10 FDPs were fixed on the plaster casts (group 1) and on the patient-models for passive fitting (group 2). The fit of each FDP was checked on the patient-model by means of visual control (grades 1-10) and microscopic examination. Furthermore, specimens were artificially aged for possible prosthodontic failures, followed by a fracture strength test. Results: Group 2 [1.4 (+/- 0.3)] showed significantly (p<0.001) better results in the visual examination of the marginal fit compared to group 1 [6.3 (+/- 2.4)]. The microscopic marginal misfit was 160mm (+/- 80 mu m) at the abutment margin and 150mm (+/- 80 mu m) at the axial wall of the abutment for group 1, respectively, 0 mu m and 0 mu m up to 17 mu m for group 2 (p<0.001). No failure of the FDPs could be observed during artificial aging in both groups. The fracture load showed no significant difference (p=0.60) between group 1 [2583N (+/- 664N)] and group 2 [2465N (+/- 238N)]. Conclusions: Visual and microscopic examination detected huge differences in marginal fit between groups 1 and 2. However, no statistically verifiable differences could be detected in long-term stability of implant-supported FDPs irrespective of the fit.
- 出版日期2017-10
