Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, Zagreb, Croatia.
Grande Plotino & Torsello - Studio di Odontoiatria, Private Practice, Rome, Italy.
Int Endod J. 2020 Jul;53(7):962-973. doi: 10.1111/iej.13287. Epub 2020 Apr 9.
To compare the retreatment ability of several rotary and reciprocating file systems in curved root canals of extracted teeth and to evaluate the influence of additional apical enlargement performed after a basic retreatment on the amount of remaining filling material.
A total of 65 round curved root canals were used. The root canals were prepared with the ProTaper Next rotary system to size 25, .06 taper and filled with an epoxy resin-based sealer and gutta-percha using continuous wave vertical compaction and warm injection back-filling. The canals were randomly divided into four groups according to the retreatment system used: Group I. ProTaper Universal Retreatment system + ProTaper Gold (PTG) instrumentation system up to PTG F2; Group II. Reciproc Blue system up to the instrument RB25; Group III. Reciproc system up to the instrument R25; Group IV. Wave One Gold (WOG) system up to the instrument WOG25. After the basic retreatment, additional apical enlargement was performed in each group with an instrument that was one size larger: in Group I, II and III up to apical size 40, and in Group IV up to 35. The final irrigation protocol included the following: 15% ethylenediaminotetraacetic acid followed by NaOCl irrigation. The volume of filling material was measured using an industrial micro-CT four times: after root canal filling (Volume I), after basic retreatment with size 25 files (Volume II), after additional root canal enlargement with larger instruments (Volume III), and after the final irrigation protocol (Volume IV). The decrease in the amount of filling material after each retreatment protocol was analysed using a Kruskal-Wallis test. Intergroup analyses were performed with a Kruskal-Wallis test and between-group differences were further analysed with Mann-Whitney U test.
There were no significant differences amongst the systems tested in the amount of remaining filling material, or the reduction rates after each phase of the retreatment procedures (P > 0.05). Intragroup analysis indicated that the use of a larger final instrument removed significantly more filling material in all groups (P < 0.001).
The four tested instrumentation systems were equally effective in removing filling materials from curved root canals in extracted teeth. Additional apical enlargement with larger files improved the removal of filling remnants after basic retreatment.
比较几种旋转和往复锉系统在离体弯曲根管中的再治疗能力，并评估在基本再治疗后进行额外的根尖扩大对剩余填充物数量的影响。
共使用 65 个圆形弯曲根管。根管用 ProTaper Next 旋转系统预备至 25 号，0.06 锥度，用环氧树脂基密封剂和牙胶采用连续波垂直压实和温热注射回填法填充。根据使用的再治疗系统，将根管随机分为四组：组 I. ProTaper Universal 再治疗系统+ProTaper Gold（PTG）器械系统至 PTG F2；组 II. Reciproc Blue 系统至器械 RB25；组 III. Reciproc 系统至器械 R25；组 IV. Wave One Gold（WOG）系统至器械 WOG25。在基本再治疗后，每组均使用比原始器械大一号的器械进行额外的根尖扩大：组 I、II 和 III 扩大至 40 号，组 IV 扩大至 35 号。最终冲洗方案包括以下步骤：15%乙二胺四乙酸（EDTA） followed by NaOCl 冲洗。使用工业微 CT 四次测量牙胶的体积：根管填充后（体积 I）、用 25 号锉进行基本再治疗后（体积 II）、用更大的器械进行额外根管扩大后（体积 III）和最后冲洗方案后（体积 IV）。使用 Kruskal-Wallis 检验分析每种再治疗方案后牙胶体积的减少。采用 Kruskal-Wallis 检验进行组间分析，并用 Mann-Whitney U 检验进一步分析组间差异。
在测试的系统中，剩余牙胶量或再治疗过程各阶段后的减少率均无显著差异（P>0.05）。组内分析表明，所有组中使用更大的最终器械均显著去除更多的牙胶（P<0.001）。
四种测试的器械系统在去除离体弯曲根管中的牙胶填充物方面同样有效。在基本再治疗后使用更大的器械进行额外的根尖扩大可改善对牙胶残余物的去除。
