Evaluation of the long-term structural change caused by root canal treatment in the bone around the tooth by fractal analysis.

Abstract

Objective: To evaluate the microarchitecture changes in the trabecular bone around (mesial and distal) the tooth after root canal treatment on panoramic radiographs by measuring the fractal dimension (FD) value change with fractal analysis (FA).

Methods: One hundred two patients (69 females, 33 males) with a mean age of 33.12 (18-69) years were included. These patients had a clinically healthy, radiologically successful root canal-treated mandibular premolar/molar tooth treated at least 1 year ago. A healthy, untreated contralateral tooth with the same tooth number had to be present (control tooth). Patients were divided into four groups according to their ages (18-24, 25-34, 35-44, and 45 +), teeth into three groups according to treatment time (1-3 years, 4-6 years, and 7-8 years), and three groups according to tooth number (35-45, 36-46, 37-47). FD measurements were made at two rectangular Region of Interest (ROI) with 20 × 60 pixels selected on the mesial and distal of the root with the Image J version 1.3 software program on panoramic radiographs. The comparison of the FD values of the treated and control teeth was performed via the Wilcoxon signed ranks test.

Results: The FD values of mesial and distal regions of root canal-treated molars were statistically significantly higher than the control teeth (p < 0.05). The treatment time, tooth number, and sex and age of the patients did not have a statistically significant effect on the increase in FD value (p > 0.05). There was a correlation between the mesial FD value changing and treatment year (r =  - 0.21, p = 0.035).

Conclusion: After the first year of root canal treatment, quantitatively measurable structural changes were observed in the trabecular bone in both the mesial and distal regions of the tooth in all age groups and sexes in the posterior teeth of the mandible.