Influence of implant dimensions and position on primary and secondary stability: a prospective clinical study in the mandible using resonance frequency analysis

Aim The aim of this study was to measure primary and secondary implant stability through the resonance frequency analysis of mandibular implants and to evaluate the influence of implant diameter and length, sex, age and site.

Materials and methods Thirty-six healthy patients who had mandibular implants placed were enrolled for the study. A total of 82 OsseoSpeed TX (Astra Tech Implant System - Dentsply Implants; Mölndal, Sweden) implants were placed, with different lengths (9, 11 and 13 mm) and diameters (3.5 and 4 mm). All implants were placed according to a conventional two-stage surgical procedure. Implant stability quotients (ISQ) were recorded at implant placement (ISQ1) and 3 months later, at second surgical stage (ISQ2). Statistical analysis was performed to investigate significant differences between implant dimensions, patient sex and age, and implant position (anterior or posterior sites). SIGMAPLOT software was used for statistical analysis (significance =0.05).

Results Secondary implant stability was statistically significantly higher compared to initial ISQ values (p<0.05). ISQ2 values were statistically significantly higher than ISQ1 values for 3.5 mm diameter implants, for 13 mm length implants and for implants placed in anterior mandible. Age was not found to influence implant stability. Female patients showed ISQ2 values significantly higher than males.

Conclusion Some parameters such as implant dimensions and positions may influence only the secondary implant stability. Male patients have lower secondary implant stability.