The Finite Element Analysis Of Telescopic Coping Retained Mandibular Implant-Surpported Overdentures

Objective: To analyze the effects of clearence fit in the telescopic crowns to stress distribution and denture mobility of mandibular implant supported overdentures under different kinds of loads when different numbers of implants were used.Methods: By means of spiral computed tomographic(SCT), three-dimentional image reconstruction and three-dimentional finite element methods to study the stress distribution of the supporting tissues of implant overdentures when rigid and non-rigid telescope copings and different numbers of implants were applied in various loading conditions.Results: The most exstreme stresses of implant and implant-bone interface are located around the implant neck. Load location and direction can influence the stress distribution and denture stability. The mesially placed load and oblique load can increase the stress value in the implant and the implant-bone interface.While, the stress in alveolar bone and denture displacement decreased when the number of implant increased.Conclusions:The study showed when the load direction is oblique or placed mesially, it could be more harmful. The study also suggested that the non-rigid telescopic copings could be advantageous for implant-supported overdentures with regard to optimizing stress in peri-implant tissue, while the increase of implant number can minimize denture movement.