Is gingival biotype a critical determinant of secondary stability of orthodontic mini-implants – a prospective clinical study using resonance frequency analysis

Objectives: The objectives of the study were to determine the association of gingival biotype and secondary stability of orthodontic mini-implants using resonance frequency analysis. Materials and Methods: Twenty patients, each receiving two mini-implants, were divided into two groups; thick and thin gingival biotype based on the thickness of gingiva before mini-implant placement. Implant stability was assessed at the time of placement; at the 1^st, 2^nd, 3^rd, and 4^th month by resonance frequency analysis. Peri-implant soft-tissue conditions were also examined at each month till 4 months interval using periodontal indices. Results: Thick and thin gingival biotype groups showed statistically different implant stability quotient (ISQ). Mini-implants showing signs of failure consistently displayed lesser ISQ. Statistically significant difference was observed in the scores of peri-implant indices of failure and no failure group of mini-implants. Conclusion: Mini-implants in thin gingival biotype are more susceptible to failure and peri-implantitis compared to thick gingival biotype. Longitudinal assessment of mini-implant stability may help predict failure so as to avoid long duration and cost of orthodontic treatment.