Multivariate Analysis of the Influence of Primary and Secondary Stability in Relation to Dental Implant Characteristics: A Clinical Study of 445 Implants.

Purpose: Implant stability (IS) is crucial to the success of any implant-based therapy. The present work aimed to determine the relationship between primary and secondary stability and a range of variables.

Material and methods: This retrospective cohort study included a total of 169 patients, who received 445 dental implants. A case history for each participant was created. Data collection included each patient's age, implant design, length and diameter, bone type, and surgical factors. Implant Stability Quotient (ISQ) values were measured at baseline (T0: primary stability) and T1 (secondary stability). To calculate the ISQ values at T0, T1 and their differences in the variables age, design, length and diameter, a multivariate ANOVA test was performed to determine which variables acted as confounding factors and to adjust the ISQ values to these variables.

Results: The main variables age, design, length and diameter were adjusted to their confounding factors. Regarding primary (T0) and secondary (T1) stability, statistically significant differences (p<0.05) were only found in implant diameter, with the larger the diameter, the greater the stability. In all the other main variables, no statistically significant differences were found for primary and secondary stability.

Conclusions: It may be concluded, within the limitations of the study, that the implant diameter variable is the one that significantly affects the primary and secondary stability of the implant.