Finite element analysis of dental implant-bone system during and after implantation

Abstract

Development of an ideal replacement for a missing tooth has been a major aim of dentistry for millennia [1]. Since Br宥mark [2] discovered the phenomenon whereby metallic implants, particularly when made of titanium, promoted a process now termed "osseointegration", dental implants have become widely used to replace missing teeth. Although implants exhibit dentally acceptable retention rates (roughly 95% after 5 years), there are significantly more failures in areas where bone quality and density are low, resulting in poor patient outcome and costing an estimated $AUD15 million per year in Australia. This research team also believes that most failures arise from poor clinical technique and inadequate understanding of the potentially damaging stress characteristics during implant placement and function. Finite Element Method (FEM) has become one of the most successful analysis tools used for solving dental related problems. As such, the innovative work of this team is to develop a comprehensive Finite Element Analysis (FEA) process to model the performance of the boneimplant system during implantation, as well as throughout the phases of healing, remodelling and maintenance of osseointegration. Summarised herein are six research domains that quantify the stress distribution characteristics within: (1) the mandible as influenced by a combined variation of implant geometry and bone properties; (2) the implant with various implant wall thicknesses; (3) the mandible as influenced by Nobel Biocare, 3i and Neoss implant thread designs; (4) the prosthetic crown with external and internal abutment-crown connection systems; (5) the mandible in a step-wise simulation of the insertion process; and (6) the mandible for implant thread forming, cutting and the combination of forming and cutting through dynamic modelling of the implantation procedure. An advanced understanding of the stress characteristics within the bone-implant system and the corresponding response of bone is the key in the development of a 'treatment planning database tool'. This in turn will increase the quality of preoperative planning, clinical techniques and outcomes.