A radiographic-based method for marginal bone loss measurement in dental implants

Radiographic assessment of marginal bone loss is one of the most used criteria in longitudinal control of dental implant osseointegration. Accurate and reproducible results are difficult to obtain, due to considerable intra- and interoperator variability. In this work a semi-automatic approach to establish the degree of osseointegration of dental implants based on radiographic images is presented. The marginal bone loss around 47 implants in 16 patients were assessed. Computer-assisted results were compared with those provided manually by three expert graders. The method provides a mean inter-variability reduced of the 70% with respect to the manual measures. Limiting the analysis to the subset of implants characterized by a manual inter-variability lower than 25%, the automatic results are well correlated with the manual measures: estimating the marginal bone loss, the value of R2 ranges from 0.62 to 0.86; estimating the screws' axis length, the value of R2 is always above 0.99.