Peak insertion torque correlated to histologically and clinically evaluated bone density.

OBJECTIVE: : Establish a correlation between dental implant insertion torque (IT) and bone density. MATERIALS AND METHODS: : In 18 patients, implant site preparation was initiated using a trephine drill to retrieve a bone biopsy and completed with standard drills. Bone type was assessed during drilling according to surgeon's tactile sense. Forty implants were placed and peak IT values were recorded. Osseointegration was evaluated clinically at abutment connection. Data were analyzed using Pearson product-moment correlation coefficient. RESULTS: : All implants but one achieved osseointegration. D1 and D4 bone types were significantly assessed using tactile sense. IT values ranged from 15 to 150 Ncm with a mean value of 78.30 Ncm. Mean IT was significantly higher in D1 bone (126.67 Ncm) and lower in D4 bone (40.22 Ncm) (P value <0.0001), whereas intermediate values were noted in D2 and D3 bone with no significant difference between these bone types (P value = 0.462). Statistically significant correlation was found between bone volume and IT values (r = +0.771, P < 0.0001). No statistically significant correlation was found between implant length and/or diameter and IT in all bone densities. CONCLUSION: : Clinical assessment of bone density during drilling may be achieved in hard and soft bone but not in intermediate densities. Increasing peak IT values correlated with increasing bone volume. High IT does not seem to alter osseointegration process.