Mineralized Bone-Implant Contact and Implant Stability Quotient in 16 Human Implants Retrieved after Early Healing Periods: A Histologic and Histomorphometric Evaluation

Purpose: Resonance frequency analysis (RFA) is a quantitative method for the measurement of implant stability. Information about the significance of RFA measurements and the relationship between RFA values and implant osseointegration, success, or failure is important from a clinical point of view. In a previous study the authors observed a strong correlation between RFA values and mineralized boneimplant contact percentage in implants retrieved after 6 months. The aim of the present histologic and histomorphometric study was to determine whether the same correlation existed at earlier time points, specifically in implants retrieved after 4 or 8 weeks. Materials and Methods: Sixteen implants, all with a sandblasted and acid-etched surface, were evaluated in the present study. The implants were retrieved for different reasons after 4 or 8 weeks of healing with a 5-mm trephine bur and immersed in 10% buffered formalin to be processed for histology. Results: A statistically insignificant correlation was detected between RFA values and mineralized bone-implant contact percentage (P = .5502) using the Friedman and Spearman tests. Conclusion: RFA should reflect the bone anchorage of the implant; however, the relationship between bone structure and RFA is not fully understood. Keywords: bone-implant contact, histology, histomorphometry, implant stability