Optimal selection of dental implant for different bone conditions based on the mechanical response.

PURPOSE: Bone quality varies from one patient to another extensively. Young's modulus may deviate up to 40% of normal bone quality, which results into alteration of bone stiffness immensely. The prime goal of this study is to design the optimum dental implant considering the mechanical response at bone implant interfaces for a patient with specific bone quality.

METHOD: 3D models of mandible and natural molar tooth were prepared from CT scan data, while dental implants were modelled using different diameter, length and porosity and FE analysis was carried out. Based on the variation in bone density, five different bone qualities were considered. First, failure analysis of implants, under maximum biting force of 250 N had been performed. Next, the implants that remained were selected for observation of mechanical response at bone implant interfaces under common chewing load of 120 N.

RESULT: Maximum Von Mises stress did not surpass the yield strength of the implant material (TiAl4V). However, factor of safety of 1.5 was considered and all but two dental implants survived the design stress or allowable stress. Under 120 N load, distribution of Von Mises stress and strain at the boneimplant interface corresponding to the rest of the implants for five bone conditions were obtained and enlisted.

CONCLUSION: Implants exhibiting interface strain within 1500-3000 microstrain range show the best bone remodelling and osseointegration. So, implant models having this range of interface strains were selected corresponding to the particular bone quality. A set of optimum dental implants for each of the bone qualities were predicted.