Department for Preventive Dentistry, Periodontology and Cariology, University Medical Center Göttingen, Göttingen, Germany.
Int Endod J. 2018 Jul;51(7):808-815. doi: 10.1111/iej.12893. Epub 2018 Feb 14.
To evaluate ex vivo the efficacy of ProTaper Universal Retreatment files (Dentsply Sirona, Ballaigues, Switzerland) in removing Thermafil, GuttaCore (both Dentsply Sirona) or vertically compacted gutta-percha from curved root canals using micro-CT.
Sixty curved molar roots with the same mean canal curvatures and radii in two directions were prepared using ProFile instruments (Dentsply Sirona) to size 30 with .04 taper and obturated with either Thermafil, GuttaCore or vertically compacted gutta-percha and AH Plus (n = 20). Specimens were retreated using the ProTaper Universal Retreatment files D1, D2 and D3 to working length, and root canal preparation was completed with ProTaper Next (Dentsply Sirona) to size ×4. Percentages of residual filling material and dentine removal were assessed using micro-CT imaging. Working time and procedural errors were recorded. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon tests.
No significant differences between carrier-based and warm vertical compaction regarding residual filling material (14.2-19.3%) and dentine removal (2.7-3.2 mm ) were detected (P > 0.05). Time to reach working length was significantly faster for canals filled with GuttaCore than that observed for Thermafil and warm vertical compaction (P < 0.05). Five lateral perforations with the D3 file occurred during retreatment, one in the Thermafil and four in the vertical compaction group.
Remaining filling material and dentine removal were similar for all canal filling techniques. Regaining working length was significantly faster for GuttaCore compared with Thermafil and vertically compacted gutta-percha. Procedural errors occurred during retreatment of severely curved root canals with the ProTaper Universal Retreatment files in 5 of 60 canals (8%).
使用 micro-CT 评估 ProTaper Universal 再治疗锉（登士柏西诺德，Ballaigues，瑞士）从弯曲根管中去除 Thermafil、GuttaCore（均为登士柏西诺德）或垂直压实牙胶的体外疗效。
使用 ProFile 器械（登士柏西诺德）将 60 个具有相同平均根管曲率和两个方向半径的磨牙弯曲根管预备至 30 号，锥度为.04，用 Thermafil、GuttaCore 或垂直压实牙胶和 AH Plus （n = 20）进行封闭。使用 ProTaper Universal 再治疗锉 D1、D2 和 D3 至工作长度进行再治疗，并用 ProTaper Next（登士柏西诺德）预备至 ×4 号。使用 micro-CT 成像评估剩余填充材料和牙本质去除的百分比。记录工作时间和操作失误。使用 Kruskal-Wallis 和 Wilcoxon 检验进行统计学分析。
在剩余填充材料（14.2-19.3%）和牙本质去除（2.7-3.2mm）方面，载体基和热垂直压实之间没有显著差异（P>0.05）。与 Thermafil 和热垂直压实相比，GuttaCore 填充的根管到达工作长度的时间明显更快（P<0.05）。在再治疗过程中，D3 锉发生了 5 个侧穿，其中 1 个在 Thermafil 组，4 个在垂直压实组。
所有根管填充技术的剩余填充材料和牙本质去除相似。与 Thermafil 和垂直压实牙胶相比，GuttaCore 恢复工作长度的速度明显更快。在 60 个根管中的 5 个（8%）严重弯曲根管的再治疗过程中发生了操作失误。
