The Performance of Abutment Material and Finish Line Configuration on the Stress Distribution and Fracture Resistance of Implant-Supported Zirconia Fixed Partial Dentures When Loaded in a Bio-Faithful Model

Abstract

This computational study analyzed the strain magnitude and distribution within trabecular bone structure around different materials and finish line (FL) configurations of implant abutments loaded axially. Differences in fracture resistance of these abutments were also assessed. Sixteen endosseous screw vent implants were embedded in eight bio-faithful mandibular simulators resembling D2 and D3 bone density (n = 4 models per bone type) in the second premolar and second molar positions. These models were further subdivided into eight subgroups with different FL configurations and abutment materials. Strain gauges were mounted adjacent to the implants, and the superstructures were successively placed on the abutments. A universal dynamometrical testing apparatus was used for a static compression load. Finally, all samples were subjected to load until fracture. Three-way analysis of variance for strain analysis showed a significant overall interaction between the three variables (bone type, FL configuration, and abutment materials; P < .001), while the analysis for fracture resistance showed significant two-way interactions between bone type and FL configuration (P < .001) and between bone type and abutment material (P < .001). The implant abutment material, the FL configuration of the abutment, and the bone type can influence the mechanical behavior of the abutment used. Zirconia abutments with anatomical FL configurations possess better fracture resistance than zirconia and titanium abutments with circular FL configurations in D2 bone density. Int J Periodontics Restorative Dent.