Fractal dimension analysis of periapical reactive bone in response to root canal treatment.

OBJECTIVE Mathematical morphology and box counting were used to extract trabecular pattern and to evaluate changes of reactive bone following root canal treatment. STUDY DESIGN Periapical radiographs were digitized and processed with mathematical morphology operations known as skeletonization. The trabecular patterns resulting from this skeletonization process were further analyzed with fractal dimension (FD) analysis using the box-counting method. Two groups of regions of interest (ROI) were selected from 19 subjects for the analysis. RESULTS Seventeen patients in one group and 13 patients in the other showed decreased FD in the reactive bone region after clinically successful root canal treatment (RCT). Significant changes in FD were noted 6 months after RCT (P < .05). Kappa analysis indicated significant reproducibility between the 2 groups of ROIs. CONCLUSIONS Mathematical morphology combined with box counting showed decrease of FD in reactive bone regions after clinically successful endodontic treatment.