In vitro and in vivo comparison between methods based on quantitative ultrasound and on resonance frequency analysis to assess dental implant stability

Abstract

Resonance frequency analyses (RFA) and quantitative ultrasound (QUS) methods have been suggested to dental assess implant stability. The aim of this study was to compare the results obtained using these two techniques in vitro and in vivo. Implants were inserted in bone phantoms with different values of density and cortical thickness to assess the effect of bone quality on the ultrasonic indicator (UI) and on the ISQ values. 81 identical implants were inserted in the iliac crests of 11 sheep. The QUS and RFA measurements were realized after different healing times. ISQ values increase and UI values decrease when i) the bone density and ii) cortical thickness increase. The error realized on the estimation of the trabecular density (respectively cortical thickness) with the QUS device is around 4 (respectively, 8) times lower compared to that made with the RFA technique. The error made on the estimation of the healing time using the QUS technique was 10 times lower than using the RFA technique. The results show that ultrasound technique provides a better estimation of different parameters related to the implant stability compared to the RFA technique, paving the way towards the development of a decision support system to dental surgeons.