Influence of Bone Implant Contact on Biomechanical performance of Short Implant Placed in Atrophic Posterior Mandible

Abstract

In excessive reduced alveolar bone height patients, thickness of cortical bone is less and available bone height for placing implant is limited. Placing conventional long implant may invasive additional bone. To minimize unnecessary bone invasion, short implants is considered to be a good option. However, Crown-to-Implant (CI) ratio remains questionable in success of dental implant at different Bone-to-Implant Contact (BIC) levels. Therefore, biomechanical performance of short implants with suprastructure on the posterior atrophic mandible was then studied for difference of BIC contact and CI ratio. Six three-dimensional (3D) finite element models of a 6-mm short implant with 6-mm and 12-mm crown height represented a CI ratio of 1:1 and 2:1, respectively, with 30%, 60%, and 90% BIC were modeled. Uniform thickness of the cortical bone model was 1-mm covering the trabecular layer. Axial force of 200 N was applied to the occlusal surface. Results revealed that the maximum von Mises stress of bone is relatively low, indicating that low chance of bone resorption occurred. Elastic strain of cortex and trabecular at BIC level 30%, 60% and 90% were almost similar for CI ratios of both 1:1 and 2:1. Magnitude of elastic strain at a 30% BIC level was also in range for physiologic bone remodelling. These findings may help patients who have risk of low osseointegration.