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

Purpose: To determine the relationship between primary stability (PS) and secondary stability (SS) and various implant characteristics.

Materials and methods: This retrospective cohort study included a total of 169 patients who received 445 dental implants. A case history was created for each participant. Data collection included each patient's age; implant design, length, and diameter; bone type; and other surgical factors. Implant stability quotient (ISQ) values were measured at baseline (T0 [for PS]) and after the appropriate osseointegration period (T1 [for SS]). To calculate the ISQ values at T0 and T1-and to compare their differences in the variables age, design, length, and diameter-a multivariate analysis of variance (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 PS (T0) and SS (T1), statistically significant differences (P < .05) were only found for implant diameter; moreover, the larger the diameter, the greater the implant stability. For all other main variables, no statistically significant differences were found for PS and SS.

Conclusions: Within the limitations of this study, it can be concluded that implant diameter is the only variable that significantly affects the PS and SS of the implant.