Influence of implant design, length, diameter, and anatomic region on implant stability: a randomized clinical trial

Objectives: To evaluate the influence of implant geometry and anatomical region on implant stability. Methods: A randomized controlled clinical trial was conducted on 45 patients, in whom a total of 79 implants were placed: 40 MIS C1 Implants and 39 MIS Seven Implants. The implant stability quotient was measured using resonance frequency analysis immediately after implant placement and 8 weeks later with an Osstell Mentor device. Results: 76 implants were analyzed. The implant stability quotient was statistically significantly higher for secondary stability than primary stability (68.7±8,6 vs. 65.2±10.3, respectively, p=0.023). Considering primary stability, no statistical differences were found between the implant lengths 8.0 mm, 10.0 mm, 11.0 mm, and 11.5 mm (67.9±7.6, 63.9±10, 57.2±11.1, and 66.4±11.3, respectively, p=0.312). The same was observed for secondary stability (68.4±9.4, 67.9±9.3, 74.7±1.5, and 69.2±7.9, respectively, p=0.504). Also, there were no statistically significant differences between the implant diameters 3.75 mm and 4.20 mm concerning primary stability (64.3±8.7 and 66.1±11.7 respectively, p=0.445) or secondary stability (68.8±8.2 and 68.7±9.1 respectively, p=0.930). Regarding implant design, a statistically significant difference was found only for secondary stability, favoring MIS Seven implants (p=0.048). The intraoral location was statistically significant for both primary and secondary stability, as these were higher on the anterior maxilla than the posterior maxilla and mandible (p<0.05). Conclusions: The diameter and length of the implants studied did not influence their stability. Implant design may influence secondary stability, whereas intraoral location has a relevant effect on primary and secondary stability.