Assessment of dental implant stability using resonance frequency analysis and quantitative ultrasound methods

Purpose: Quantitative ultrasound (QUS) and resonance frequency analyses (RFA) are promising methods to assess the stability of dental implants. The aim of this in vivo preclinical study is to compare the results obtained with these two techniques with the bone-implant contact (BIC) ratio, which is the gold standard to assess dental implant stability. Methods: Twenty-two identical dental implants were inserted in the tibia and femur of 12 rabbits, which were sacrificed after different healing durations (0, 4. 8 and 13 weeks). For each implant, the ultrasonic indicator (LI) and the implant stability quotient (ISQ) were retrieved just before the animal sacrifice using the QUS and RFA techniques, respectively. Histomorphometric analyses were carried out to estimate the hone-implant contact ratio. Results: UI values were found to be better correlated to BIC values (R-2=0.47) compared to ISQ values (R-2=0.39 for measurements in one direction and R-2=0.18 for the other direction). which were shown to be dependent on the direction of measurements. Errors realized on the UI were around 3.3 times lower to the ones realized on the ISQ. Conclusions: QUS provide a better estimation of dental implant stability compared to RFA. This study paves the way for the future clinical development of a medical device aiming at assessing dental implant stability in a patient-specific manner. Clinical studies should confirm these results in the future.