Statistical analysis of implant and thread parameters effects on dental implant stability and bone resorption using central composite design method.

Abstract

The effect of dental implant parameters, length and diameter, and thread parameters consisting of thread depth, width, pitch and inner angle on Max von-Mises stress in implant-abutment and cancellous bone is investigated. A three-dimensional finite element model of a threaded dental implant and mandibular segment is built. Face-centered central composite design is applied as the design of experiments method to study and optimize the six independent variable parameters at three levels by applying response surface methodology. The simultaneous analysis of these parameters is run to obtain a better perspective on their effects on responses. The effects of linear, square, and interactive terms on responses through Pareto, main effects, and interaction plots are determined through analysis of variance. A second-order polynomial equation is fitted to the model to predict the response magnitude. The results indicate that implant diameter and its interaction with thread depth are effective in decreasing the likelihood of bone resorption. The implant length affects the Max von-Mises stress in implant-abutment, with no effect on the Max von-Mises stress in cancellous bone. The optimization process caused about 10% and 30% reduction in the magnitude of Max von-Mises stress in implant-abutment and cancellous bone, respectively.