Fractal Analysis of Periapical Bone Healing Following Endodontic Treatment in Pediatric Patients

Objective:This study aimed to quantitatively evaluate trabecular bone structural changes following root canal treatment (RCT) in pediatric patients using fractal analysis (FA) and to investigate its relationship with Periapical Index (PAI)–based healing. Methods:Forty-one single-rooted anterior teeth from patients aged ≤16 years were included. Periapical radiographs obtained immediately after treatment (T0) and during follow-up (T1) were analyzed. Fractal dimension (FD) values were calculated from standardized regions of interest. Periapical healing was assessed using PAI and classified as healed (PAI < 3) or non-healed (PAI ≥ 3). Comparisons were performed according to follow-up duration (≤1 year and >1 year). Agreement between FD change and PAI change was evaluated using intraclass correlation coefficient (ICC) and Bland–Altman analysis. Categorical agreement between FD- and PAI-based healing classifications was assessed using Cohen’s kappa.Results:FD values showed a significant decrease within the ≤1-year follow-up group (p = 0.049), whereas no significant change was observed beyond 1 year (p = 0.782). Overall FD values demonstrated a decreasing trend from T0 to T1 without statistical significance (p = 0.106). PAI scores decreased significantly in the total sample (p = 0.004). Agreement between FD change and PAI change was negligible (ICC = 0.014; p = 0.466), and categorical agreement was also non-significant (κ = −0.029; p = 0.853). Lower age was independently associated with PAI non-healing (adjusted OR = 0.584 per 1-year increase in age; p = 0.041).Conclusions:FD values exhibited a decreasing trend after RCT, particularly within the first year, supporting reactive bone remodeling toward normal trabecular architecture. The negligible agreement between FD- and PAI-based changes indicates that these measures capture distinct biological dimensions of periapical recovery and should not be considered interchangeable; however, their combined use may provide complementary insights into microarchitectural remodeling and conventional radiographic healing.