DESCRIPTION (provided by applicant): Although dental implants are not yet the standard of care for edentulous patients, the use of this treatment option is rapidly increasing. The number of implants placed in the US increased by a factor of ten from 1983 to 2002 with $150 million of implant products sold to North American dentists in 2002. In the absence of implant placement, edentulism poses a serious health concern for US citizens. Without a tooth or implant to transfer loading to the alveolar bone, patients experience bone resorption with an average decrease of 4 mm in mandibular height within one year. It has been suggested that with proper treatment, achieving stable biointegration is no longer the primary factor limiting the lifetimes of implants. Fatigue fracture of the implant or the prostheses supported by the implant due to mechanical factors is a more prevalent cause of failure. Implant body diameter, prosthesis cementation method, and implant-abutment connection design have all been reported to significantly affect abutment screw loosening and fracture. It is clear that the dental implant community would benefit from systemic comparisons of implant designs, but such studies are not feasible without more efficient fatigue testing methods. The following specific aims are focused around our central goal of developing an efficient method for testing reliability of dental implants: 1) Correlate the results of finite element stress analysis to the fracture origin observed on physical specimens. 2) Verify the accuracy of step-stress method for estimating the mechanical reliability of dental implants over time. 3) Determine an acceleration factor to allow conversion between fatigue data collected at different cyclic frequencies. In lay terms, this project will enable future researchers to improve dental products by faster methods.