Prediction of implant loss and marginal bone loss by analysis of dental panoramic radiographs

Purpose: One of the major factors governing implant success is the quantity and density of the host bone. The aim of this work was to determine whether mandibular bone texture features and cortical width measurements on plain radiographs could be associated with implant failure and/or marginal bone loss. Material and Methods: A statistical model was built to predict implant failure; it incorporated several radiographic features of cortical and cancellous bone texture, cortical width and patient smoking habits. Cortical width measurements and texture measurements of cortical and cancellous bone were made on the panoramic radiographs of 460 subjects. These were used to predict implant failure and marginal bone loss after 5 years. Receiver operating characteristic (ROC) curve analysis and the area under the curve (AUC) were used to determine the diagnostic accuracy of the variables in predicting implant failure and marginal bone loss. Additionally, for 91 of 460 subjects with periapical radiographs, marginal bone levels around implants were measured over a 5 year period. Results: Of the 460 patients assessed for implant failure, 29 had failed implants (93.7% success rate). The ROC curve, built from this model had a sensitivity of 62.1% and specificity of 67.5%. The area under the curve (AUC) from the model was 0.690 (95% confidence interval [CI] 0.597 to 0.783). A model was also built to predict marginal bone loss. The ROC curve had 78.6% sensitivity and 74.6% specificity (AUC = 0.880, 95% CI = 0.810 to 0.953). Mandibular cortical width was not a significant predictor variable of either implant failure or bone loss. Conclusion: In a retrospective analysis 5 years after implant placement, features of cancellous and cortical bone of the mandible were significant in predicting implant failure and marginal bone loss in a sample of 460 patients.