Influence of implant with different dimensions and designs in ideal stress distribution in bone for application in compromised situations: Analysis by three-dimensional finite element method

Abstract

Background : To determine the value and direction of the stress and strain across the different implants placed in the bone when loaded with normal or heavy forces; with either a healthy or compromised anatomical condition is always a controversial topic with quite a bit of ambiguity. Studies suggest more favorable stress distribution in bone with a wider diameter implant and by selecting threaded implant. Ideally 12 mm implant length needs to be maintained in favorable condition but the same rule cannot be applied in compromised anatomical conditions. There is a need for a study to evaluate the favorable stress distribution in bone using different implant dimensions and designs both threaded and nonthreaded, to achieve a better control over loading and stress release. Objectives: A finite element analysis (FEA) study was designed to study ideal stress distribution in cancellous and cortical bone under axial and nonaxial loading using, (1) different implant dimensions and (2) designs. Materials and Methods: A finite element models of eight dental implants with crowns were modeled using Catia, a modeling software with material properties as limitation (FEA elements = 113,388, FEA nodes = 173,212). Results: Magnitude of stresses along the implants and surrounding bone did not increase appreciably when the implant length was changed from 10 to 14 mm. With the increase in implant diameter, the stress levels within the bone reduced in threaded implant and in nonthreaded implant the stress levels increased.Conclusion: The results indicate that, for implants with a wider diameter and in threaded implant with a shorter length, there was favorable distribution of stress and strain pattern during axial and nonaxial loading.