Effects of root-end filling on the fractal dimension of the periapical bone after periapical surgery: retrospective study

Objective The aim of this study was to investigate the effects of root-end filling after periapical surgery on the fractal dimension (FD) of the periapical bone. Methods Thirty-eight patients who underwent periapical surgery were included in this study. The cases were divided into two subgroups: (1) In the gutta-percha group, root cavity and root-end fillings were not performed after root resection. In this group, there were 14 female patients and 6 male patients. (2) In the mineral trioxide aggregate (MTA) group, the root end was filled with MTA after root resection. In this group, there were 13 female patients and 5 male patients. Each patient underwent two periapical radiographs, one shortly after periapical surgery (10–15 days) and another one 1 year after periapical surgery. Regions of interest (ROIs) located close to the infected root apex were selected for each radiograph. Periapical radiographs were digitized and processed with an FD analysis using the box-counting method. Results FD was significantly increased in both groups over time ( p 0.05). Conclusions Mathematical morphology combined with the box-counting method showed that the FD change was independent of the root-end filling at the 1-year follow-up after periapical surgery. Clinical relevance Because of the complex anatomy of the root canal, orthograde endodontic treatment may be inadequate and periapical surgery becomes an alternative in these cases. In this study, the effect of root-end filling on the increase in trabecular bone after periapical surgery was investigated using fractal analysis.