ObjectiveThe aim of this study was to investigate the influence of different bone tissue characteristics of implant sites on changes in marginal bone level and implant stability over time. Material and methodsOne hundred and one implants were inserted in 41 patients. Cortical bone thickness of the alveolar ridge was measured on computed tomography (CT) images. Histomorphometric and microtomographic analyses (microCT) were performed in bone specimens obtained by using a trephine bur, at first drilling. Implant stability quotient (ISQ) measured by resonance frequency analysis (RFA) was registered at implant insertion. Implant stability quotient was measured also at the stages of uncovering, loading and at the 1-year follow-up, when standardized periapical radiographs were taken to measure the marginal bone level (MBL). Descriptive statistics, Spearman's rho correlation and multiple linear regression were used for data analysis (P<0.05). ResultsComparison between groups of higher and lower values of ISQ changes and between groups of higher and lower values of MBL changes revealed no differences in histomorphometric and microtomographic parameters, according to non-parametric comparison tests, (P>0.05). Bivariate correlation also showed no association among these microstructural parameters and the outcomes evaluated. There was no correlation between cortical thickness and MBL changes (r=-0.029; P=0.832) and between cortical thickness and ISQ changes (r=0.145; P=0.292). ConclusionMicrostructural bone characteristics of implant sites have no effect on changes in marginal bone level and implant stability as measured by RFA. Bone morphology cannot predict implant treatment success over time.