Advanced System for Implant Stability Testing (ASIST).

This study presents the Advanced System for Implant Stability Testing (ASIST) which provides a non-invasive, quantitative measure of the stability of percutaneous implants used for craniofacial rehabilitation such as bone anchored hearing aids or dental implants. The ASIST uses an impact technique coupled with an analytical model which allows the measure to be independent of the system components. This paper presents a laboratory evaluation of the ASIST for the Oticon Medical Ponto and the Cochlear Baha Connect bone anchored hearing aid (BAHA) systems. There is minimal effect of abutment length on the ASIST Stability Coefficient (ASC) value, indicating that the method is able to isolate the interface properties from the overall system and the measurement is independent of attached components. Additionally, the ASIST was able to detect differences between different implant installations suggesting that it may be sensitive to changes in interface stiffness.