Departments of Endodontology Prosthetic Dentistry, The Goldschleger School of Dental Medicine, Tel Aviv University, Ramat Aviv, Tel Aviv, Israel.
Int Endod J. 2012 Jan;45(1):35-41. doi: 10.1111/j.1365-2591.2011.01944.x. Epub 2011 Sep 8.
To test and compare the efficacy of five methods for the removal of root filling material and to test the hypothesis that radiographs fail to represent the real extent of remaining material on canal walls.
Fifty maxillary anterior single-rooted teeth with straight root canals were selected. The coronal third of each root canal was prepared with Gates-Glidden drills to number 3, whilst the apical two-thirds were prepared with manual K-files to size 40. Root fillings were performed using lateral compaction with gutta-percha and AH-26. After full setting, the coronal third of the root filling was removed with Gates-Glidden drills and the teeth divided into five groups (n=10). The remaining root filling material was then removed with either Hedström files and chloroform (25 μL), using size 40 as the last file, SafeSider files, using a NiTi Pleezer reamer with a 0.06 taper followed by size 40 reciprocating file, with or without chloroform, or ProTaper Universal retreatment files (D2, D3) with or without chloroform. Reaching working length with no more gutta-percha on the last file was defined as the endpoint for all procedures. The presence of remaining filling material was first evaluated radiographically and then by the microscopic evaluation of split roots. The time required to accomplish the procedure was also recorded. anova and anova with repeated measures were used for statistical analysis of the results.
Overall, 11-26% of the canal wall remained covered with filling material; no significant difference was found between the groups. The mechanized methods were faster than manual removal of filling material (P < 0.01); the use of solvent did not speed up the mechanized procedures. Radiographic evaluation failed to adequately and reliably detect the extent of filling material remaining on the canal walls, which was later observed by microscopic evaluation.
All methods left root canal filling material on the canal walls. Radiographic evaluation failed to detect the extent of remaining root filling material, which could only be detected using microscopy.
测试和比较五种去除根管充填材料的方法的效果，并验证射线照相不能反映根管壁上剩余材料的实际程度这一假设。
选择 50 颗上颌前单根直根管牙。用 Gates-Glidden 锉将每个根管的冠三分之一制备到 3 号，而根尖的三分之二用手动 K 锉制备到 40 号。使用侧方加压技术用牙胶和 AH-26 进行根管充填。完全凝固后，用 Gates-Glidden 锉去除根管充填的冠三分之一，将牙齿分为五组（n=10）。然后用 Hedström 锉和氯仿（25 μL）去除剩余的根管充填材料，用 40 号锉作为最后一根锉，用带有 0.06 锥度的镍钛 Pleezer 扩孔锉和 40 号往复锉去除剩余的根管充填材料，氯仿与否，或用 ProTaper Universal 再治疗锉（D2、D3）去除剩余的根管充填材料，氯仿与否。最后一根锉上没有更多牙胶到达工作长度被定义为所有程序的终点。首先通过射线照相评估剩余填充物的存在，然后通过根管劈开的显微镜评估来评估。还记录了完成程序所需的时间。使用方差分析和重复测量方差分析对结果进行统计分析。
总体而言，11-26%的根管壁仍被填充物覆盖；组间无显著差异。机械方法比手动去除填充物更快（P<0.01）；使用溶剂并没有加快机械程序。射线照相评估不能充分和可靠地检测根管壁上残留的填充物的程度，这只能通过显微镜评估来观察。
所有方法都在根管壁上留下了根管充填材料。射线照相评估未能检测到根管壁上剩余的根管充填材料的程度，只能通过显微镜检测到。
