The Prognostic Accuracy of Bone Density and Alveolar Ridge Width Estimated by CBCT in Predicting Primary Implant Stability: A Clinical Study.

BACKGROUND: Preoperative prediction of primary implant stability may improve treatment planning in the esthetic maxilla. This prospective clinical study in female patients evaluated whether CBCT-based bone density, alveolar ridge width, and histomorphometric trabecular bone content are associated with primary implant stability, and assessed the feasibility of preoperative prediction using CBCT-derived variables. MATERIALS AND METHODS: Thirty-five implant sites in the maxillary esthetic zone were included. Preoperative CBCT was used to record bone density as mean gray value (GV) at the planned implant site, and ridge width was measured at 1, 3, and 6 mm apical to the crestal level. Histomorphometry quantified percent area of bone trabeculae (%BT) from biopsy sections obtained prior to implant placement. Primary stability was recorded as implant stability quotient (ISQ). Associations were analyzed using Pearson correlation. A multivariable regression model was constructed to explore a purely preoperative prediction approach for ISQ using CBCT-derived variables. RESULTS: ISQ demonstrated significant positive correlations with % BT (r = 0.609, p < 0.001), ridge width at 1 mm (r = 0.423, p = 0.011), 3 mm (r = 0.572, p < 0.001), and 6 mm (r = 0.480, p = 0.003), and CBCT bone density (GV) (r = 0.483, p = 0.003). The final regression model was significant (F(2,32) = 16.240, p < 0.001) and explained 50.4% of ISQ variance (R² = 0.504; adjusted R² = 0.473; residual standard error = 8.156). Both predictors were independently associated with ISQ (GV: B = 0.019, p = 0.002; Width3mm: B = 4.539, p < 0.001). Cross-validation showed stable performance (CV R² = 0.541; root mean square error (RMSE) = 8.18). CONCLUSION: CBCT-derived bone density and ridge width are significantly associated with primary implant stability and can preoperatively predict ISQ with moderate explanatory power. The proposed prediction equation (ISQ = 23.770 + 0.019 × GV + 4.539 × Ridge width at 3 mm) may assist clinicians in estimating primary implant stability before implant placement in female patients.