ABSTRACT
AIM: This single-centre retrospective case-control study evaluated fractal dimension (FD) changes in radiographs of periapical lesions using a fractal analysis in healthy individuals and type 2 diabetes mellitus (DM) patients following root canal treatment. METHODOLOGY: The study data consisted of two groups: the DM group which contained a total of 46 mandibular molar teeth in 37 patients with no systemic disease other than type 2 DM, and the control group which contained a total of 52 mandibular molar teeth in 41 patients without systemic disease. Periapical radiographs were obtained prior to root canal treatment and 1 year post-treatment. Fractal analysis was performed by selecting a region of interest on the periapical radiographs. For both groups, the FD changes in lesion area were calculated and compared. In addition, periapical status was evaluated using the periapical index (PAI) scores on periapical radiographs for both groups. Data were analysed using dependent-sample t-test, independent-sample t-test, Wilcoxon signed-rank test and Mann-Whitney U-test. RESULTS: In both groups, FD values were increased significantly 1 year post-treatment as compared with those prior to treatment (P < 0.05). The time-dependent increase in FD was significantly greater in the control group (P < 0.05). Time-dependent increases in FD did not differ between genders (P > 0.05). There was a significant decrease in PAI scores in both type 2 DM and control groups depending on time (P < 0.05). No significant difference was found between the groups in terms of time-related decreases in PAI scores (P > 0.05). CONCLUSION: An increase in the FD of the periapical lesion area was observed 1 year after root canal treatment. DM had a negative effect on FD increase.