A COMPARISON OF TAPER-IMPLANT DESIGNS AND BONE QUALITY ON THE PRIMARY STABILITY: AN IN VITRO BIOMECHANICAL STUDY

Abstract

Objective To investigate the effect of the taper-implant design and the effect of bone quality on the primary stability in terms of insertion torque test, removal torque test and resonance frequency analysis. Methods Five taper-implant designs were test in artificial bone blocks with four qualities. Five repetitions per implant design were placed in each bone quality started from softest bone block. The implant motor was used to prepared the osteotomy sites and implant insertion according to manufacturers' recommendation. Peak insertion torque values were measured and recorded by implant motor when the platform of the implant flush to the bone level. Resonance frequency analysis was measure by Osstell ISQ device. The implant stability quotients were recorded. Finally, the implants were unscrewed by implant motor and the peak removal torque values were recorded. Same implants were reused with the same protocol in the rest of the test, from softer to harder test blocks respectively. The data of insertion torque values, implant stability quotients and removal torque values were statistically analysed by two-way factorial ANOVA to investigate the interaction effect of two independent variables (implant design and bone quality), (p=0.05). Results In insertion torque and removal torque tests, the interaction effects of implant design and bone quality were statistically significant. However, the interaction effect was not found in resonance frequency analysis group. Conclusion Within the limitations of this study, it can be concluded that selecting the proper design of tapered implant regarding to the quality of surgical bone site can achieve predictable primary stability outcome in terms of insertion torque and removal torque.