Implant Primary Stability Determined by Resonance Frequency Analysis in Surgically Created Defects: A Pilot Cadaver Study

AIM: Implant primary stability is a prerequisite for implant success. A dehiscence or a circumferential defect (CD) at the time of implant placement presents a challenge for achieving primary stability. The aim of this study was to examine the correlations between implant primary stability determined by resonance frequency analysis (RFA) and periimplant bone levels. MATERIALS: Ten implants were placed in 2 cadaver heads. A series of different sizes of narrow (NDD) and wide (WDD) dehiscence defects and CDs were surgically created around 6 and 4 implants, respectively. Implant primary stability in each size of the 3 different defect types was measured with RFA. For each defect type, the association between the RFA readings and the defect size was plotted and statistically analyzed. RESULTS: In NDD study, the RFA readings were not correlated with the defect size. In WDD study, the association was significant for most implants, with the coefficient correlation (r) ranging from -0.88 to -0.97. In CD study, there was also a significant association between the implant stability quotient readings and the bone levels, and the r ranged from -0.94 to -0.99. CONCLUSION: The association between implant primary stability measured by RFA and the size of surrounding bone defects was defect type dependent. The correlation was highly significant for WDD and CD but not for NDD.