Effect of different fixed detachable implant supported prosthesis materials on the stresses induced on the supporting structures

Objectives: This study was conducted to evaluate the effect of different implant supported fixed detachable prosthesis materials (chrome cobalt-acrylic and BioHPP (Bio-High Performance Polyether)) on the stresses induced on the supporting structures.
Materials and methods: A maxillary completely edentulous resin cast was 3d printed with four implant sites (two straight anterior implants and two tilted posterior implants), mucosal space for mucosa simulation and vertical slots for strain gauges which were 1mm distal to the two distal implants. Four implant analogues were placed in their sites. Multiunit abutments were secured to the implants, then fixed detachable prostheses were fabricated. In this study two models were conducted: Group (A): Complete implant supported chrome cobalt-acrylic fixed detachable prosthesis. Group (B): Complete implant supported BioHPP fixed detachable prosthesis. Strain gauges were supplied with fully encapsulated grids and attached wires. Micro strains were recorded at each site of the strain gauges with enough time elapsed between each testing. The applied load started from 0 up to 100N. T test was used for comparison between the groups, at a significance level of
P ≤0.05.
Results: Group A (chrome cobalt- acrylic prosthesis) showed higher induced stresses on supporting structures compared to group B (BioHPP) during bilateral, unilateral, and oblique loading. Independent T test showed statistically significant difference between the studied groups, P value was <0.05.
Conclusion: Unilateral loading was more traumatic to the implants as compared to bilateral loading. BioHPP prosthesis has damping effect as it transferred less stresses to the supporting structures compared to chrome cobalt- acrylic prosthesis.