Purpose: To evaluate the bone density using the surgeon's tactile sense and compare it to the Lekholm and Zarb classification and computed tomography (CT) scan to see if correlations exist.
Materials and methods: Fifty-two implants were inserted in 22 patients. The bone densities of recipient site were preoperatively determined by density value as Hounsfield Units (HU) using CT scans. According to the Lekholm and Zarb classification, the bone quality scored 1 to 4 on cross-sectional CT. The clinical hardness of recipient sites were assessed on drilling by the surgeon's tactile sense and recorded as D1-D4 based on Misch criteria. Linear regression analysis was used to evaluate the relationship between density values of implant sites.
Results: The mean bone density was 536.94 ± 220.39 HU. There were 7.7% implants in bone type D1, 46.2% in D2, 32.7% in D3, and 13.5% in D4. Bone classification according to Lekholm and Zarb was significantly correlated to the surgeon's tactile sense (Spearman's rho = 0.36; P = 0.01) and with HU on CT images (Spearman's rho = -0.61; P < 0.001). The surgeon's tactile sense had a significant correlation with bone density in preoperative CT scans (Spearman's rho = -0.67; P < 0.001). A significant correlation was found between the bone density in HU with age (Spearman's rho = 0.34; P = 0.01).
Conclusion: A high-quality cross-sectional CT may suffice as a site-specific preoperative diagnostic predictor that can confirm and complement the tactile sense of the surgeon to help differentiate good, moderate, and poor bone density.