Evaluation of the relationship between Periotest values, marginal bone loss, and stability of single dental implants: A 3-year prospective study

Statement of problem: Although the Periotest has been shown to provide reliable information about initial implant stability, whether Periotest values (PTVs) can be correlated with the stability of implants in function for several years is unclear. Purpose: The purpose of this prospective clinical study was to investigate implant stability by using PTVs, as well as changes in stability and peri-implant marginal bone levels (as measured by radiographs) over a 3-year follow-up period. The exploratory hypothesis was that there is a significant correlation between PTVs and bone loss around the implant and that PTVs can provide predictive information about marginal bone-level changes and implant stability over time. Material and methods: The study population included patients who needed single-tooth replacement with restoration of cemented fixed partial dentures. Clinical data, PTVs, and periapical radiographs were collected at the time points of implant placement, 3 to 6 months after insertion, and 1 year, 2 years, and 3 years after the final definitive prosthetic restoration. Pearson correlation coefficient tests were performed to estimate the correlation between the PTVs received at the first follow-up time point and the subsequent PTVs received during the follow-up period (up to 3 years after the restoration). The Pearson test was applied, as well as the t test and repeated-measures ANOVA, to evaluate PTVs and bone loss changes over time. The Pearson test was also applied to estimate the correlation between the bone loss values measured at the first follow-up visit and the subsequent bone loss values at the annual follow-up time points (up to and including 3 years after the restoration). Results: A total of 43 implants were inserted in 34 patients (26 men and 8 women); the average patient age was 52.8 years. A significant reduction in implant stability was detected between implant insertion and the 3- to 6-month follow-up time point, which was then followed by a significant increase in stability at the 1-year follow-up time point and then stabilized during the 2- and 3-year follow-up time points (P<.014). Furthermore, a significant correlation was found between PTVs at the 1-year follow-up and the PTVs at all measured follow-up time points (P<.05). A positive correlation was obtained with high-strength correlation coefficient R (R>0.7) at all follow-up time points. Bone loss changes during the follow-up time points were significantly different and correlated with PTVs (P<.001). Conclusions: The Periotest is a reliable device for assessing implant stability and providing predictive information about marginal bone level changes around an implant.