| In order to develop in vitro testing to measure the force transmission between dental implants and attached prostheses, this dissertation proposes a new approach involving a robot simulation system. The system has been designed to produce simulated mandibular movements and occlusal contact forces so that various implant designs and procedures can be thoroughly tested and evaluated prior to animal testing or human clinical trial. A set of noncontact displacement probes are used to measure lower jaw/implant deformations during simulated chewing. A multi-axis force/torque sensor is mounted on the end effector for measurement and feedback of overall force levels, and a system of strain gages is used to ascertain force levels transmitted by individual teeth. Quantitative and qualitative analyses of the resultant data have been performed to understand the mechanism of the force transformation between the force load and the implant-tooth combination during various chewing cycles. A theoretical model also has been established. It is found that torque in retaining screws, friction coefficient of implant material, and its geometry can have significant effects on the stability of a dental implant system. Two types of dental bridge connections, with a rigid connector and a nonrigid connector, has been constructed and used for experimental verification. A significant displacement difference in premolars are observed. This information will be useful in understanding the manner in which potentially harmful levels of force are transmitted to human bone surrounding dental implants and adjacent teeth, by providing more accurate force input data for finite element models which are under development. This investigation would provide the unique opportunity to combine robotics with dentistry to improve the oral health of patients. |
