Stress distribution patterns of implant supported overdentures-analog versus finite element analysis: A comparative in-vitro study

AIMS AND OBJECTIVES: The aim of this study was to asses & compare the load transfer characteristics of Ball/O-ring and Bar/Clip attachment systems in implant supported overdentures using analog and finite element analysis models. METHODOLOGY: For the analog part of the study, castable bar was used for the bar and clip attachment and a metallic housing with a rubber O-ring component was used for the ball/O-ring attachment. The stress on the implant surface was measured using the strain-gauge technique. For the finite element analysis, the model were fabricated and load applications were done in a similar manner as in analog study. RESULTS: The difference between both the attachment systems was found to be statistically significant (P<0.001). CONCLUSION: Ball/O-ring attachment system transmitted lesser amount of stresses to the implants on the non-loading side, as compared to the Bar-Clip attachment system. When overall stress distribution is compared, the Bar-Clip attachment seems to perform better than the Ball/O-ring attachment, because the force was distributed better.