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Updated: Mar 7, 2026
Quasistatic Mechanical Testing for Computer-Aided Design and Manufacturing Occlusal Veneers Cemented to Milled Dentin Analog Material
Published on: December 20, 2024
Accuracy and mechanical performance of passivated and conventional fabricated 3-unit fixed dental prosthesis on
Michael Stimmelmayr1, Julian Groesser2, Florian Beuer3
1Private Practice for Oral Surgery, Josef-Heilingbrunnerstr. 2, 93413 Cham, Germany; University of Munich, Department of Prosthodontics, Goethestr. 70, 80336 Munich, Germany.
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 pre-fabricated 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 160μm (±80μm) at the abutment margin and 150μm (±80μm) at the axial wall of the abutment for group 1, respectively, 0μm and 0μm up to 17μm 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.
