Influence of implant design, length, diameter, and anatomic region on implant stability: a randomized clinical trial
Authors:   Specialization in Implantology, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal, Moreira André ,   Department of Oral Surgery and Implant Dentistry, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Implantology Institute, Lisbon, Portugal, Rosa José ,   Specialization in Implantology, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal, Freitas Filipe ,   Specialization in Implantology, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Department of Oral Surgery and Implant Dentistry, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Implantology Institute, Lisbon, Portugal, Francisco Helena ,   Department of Oral Surgery and Implant Dentistry, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Implantology Institute, Lisbon, Portugal, Luís Henrique ,   Department of Biostatistics, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Center for Innovative Care and Health Technology (ciTechcare), Polytechnic of Leiria, Leiria, Portugal, Caramês João ,   Department of Oral Surgery and Implant Dentistry, Faculdade de Medicina Dentária da Universidade de Lisboa, Lisbon, Portugal,   Implantology Institute, Lisbon, Portugal
Published: March 2021

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.