Implant primary stability determined by resonance frequency analysis: correlation with insertion torque, histologic bone volume, and torsional stability at 6 weeks.

Objective: To determine if resonance frequency analysis (RFA) correlated with insertion torque (IT), bone volume (BV), and clinical osseointegration at 6 weeks.

Materials And Methods: For 18 patients, BV was evaluated histologically by retrieving bone core biopsies before placement of 40 dental implants. Peak IT was recorded at implant placement, and RFA values (implant stability quotient [ISQ]) were noted at baseline, 3 weeks, and 6 weeks. Osseointegration was evaluated at 6 weeks when torquing abutments to 30 N. ISQ values were correlated with IT, BV and abutment torquing results. Data were statistically analyzed.

Results: ISQ values significantly decreased at 3 weeks and increased at 6 weeks. There was a significant positive correlation between BV and ISQ at baseline and at 3 weeks, but not at 6 weeks, and between ISQ and jaw location, implant diameter and IT at baseline, 3 weeks, and 6 weeks. There was a significant correlation between spinning/painful implants during abutment torquing and low ISQ, low BV, and low IT values.

Conclusion: Correlations between BV and IT values, and ISQ suggest that RFA may indicate primary implant stability. BV, IT, and ISQ values may anticipate the degree of osseointegration at 6 weeks.