Assistant Professor, Department of Endodontics, Faculty of Dentistry, Pamukkale University, Denizli, Turkey.
Associate Professor, Department of Endodontics, Faculty of Dentistry, Katip Çelebi University, İzmir, Turkey.
Oral Surg Oral Med Oral Pathol Oral Radiol. 2022 Feb;133(2):245-251. doi: 10.1016/j.oooo.2021.08.016. Epub 2021 Aug 30.
This retrospective study compared changes in periapical trabecular patterns using fractal analysis and the periapical index (PAI) on the periapical radiographs of patients who underwent multivisit nonsurgical endodontic retreatment of persistent periapical disease.
In total, 50 participants were included in the study. For each patient, baseline periapical radiographs were acquired just before retreatment and postoperative radiographs were acquired 1 year later. The region of interest, located in the abnormal tissue around the root apex, was selected from each of the paired radiographs and the fractal dimension (FD) was calculated. Periapical status was classified using the PAI as "healed" (PAI <3) or "unhealed" (PAI ≥3).
According to the PAI scores, retreatment after 1 year had a healing rate of 70%. In healed cases, the FD values increased significantly (P < .001), whereas FD decreased significantly in unhealed cases (P = .021). Change in FD was significantly different between healed and unhealed cases (P < .001). However, change in FD did not have a significant correlation with PAI in either healed or unhealed cases (P > .05). There was no significant effect of sex on the change in FD values in either healed or unhealed cases (P ≥ .690).
The significant differences in FD suggest that this parameter may be useful in detecting increased trabeculation and estimating retreatment prognosis.
本回顾性研究比较了采用分形分析和根尖指数（PAI）评估多疗程非手术根管再治疗持续性根尖周病患者根尖周骨小梁形态变化。
共有 50 名患者纳入本研究。每位患者在再治疗前和 1 年后分别获取基线根尖片和术后根尖片。从每对根尖片中选择位于根尖异常组织的感兴趣区域，并计算分形维数（FD）。采用 PAI 将根尖周状态分为“愈合”（PAI<3）或“未愈合”（PAI≥3）。
根据 PAI 评分，1 年后的再治疗愈合率为 70%。在愈合病例中，FD 值显著增加（P<.001），而未愈合病例中 FD 值显著降低（P=.021）。愈合和未愈合病例之间 FD 的变化差异有统计学意义（P<.001）。然而，愈合和未愈合病例中 FD 的变化与 PAI 均无显著相关性（P>.05）。在愈合和未愈合病例中，FD 值的变化与性别均无显著相关性（P≥.690）。
FD 的显著差异表明，该参数可能有助于检测骨小梁增加并估计再治疗预后。
