Damping Factor as a Diagnostic Parameter for Assessment of Osseointegration during the Dental Implant Healing Process: An Experimental Study in Rabbits

The purpose of this study was to evaluate the possibility of using damping factor (DF) analysis to provide additional information on osseointegration of dental implants during the healing period. A total of 30 dental implants were installed in the bilateral femoral condyles of 15 rabbits. A DF analyzer detected with an impulse-forced vibration method and a commercialized dental implant stability analyzer based on resonance frequency (RF) analysis were used to measure the implant stability immediately after implant placement and 1, 2, 4, and 8 weeks post-surgically. Results of DF and RF analyses at different time points were compared with the corresponding osseointegration performance of dental implants via micro-computed tomography (micro-CT), histological and histomorphometrical analysis. The DF values revealed a decrease with time and reached 0.062 ± 0.007 at 8 weeks after implantation, which is almost 50% lower than the initial value. Moreover, highly significant correlations between DF values and bone volume densities (R² = 0.9797) and percentages of bone-to-implant contact measured at trabecular bone area (R² = 0.9773) were also observed. These results suggested that DF analysis combined with RF analysis results in a more sensitive assessment of changes in the dental implant/bone complex during the healing period than RF analysis alone.