Kanaparthy Aruna, Kanaparthy Rosaiah
Assistant Professor, Department of Operative Dentistry & Endodontics, College of Dentistry, Jizan University , Jizan, Saudi Arabia .
Assistant Professor, Department of Periodontics, College of Dentistry, Jizan University , Jizan, Saudi Arabia .
J Clin Diagn Res. 2016 May;10(5):ZC130-3. doi: 10.7860/JCDR/2016/17731.7845. Epub 2016 May 1.
Root canal treatment enjoys a high success rate all over the world and has saved billions of teeth from extraction. However, there are instances of failure, the main causes being insufficient cleaning and inadequate obturation. In such cases the most conservative treatment option would be non-surgical retreatment. It requires regaining access to the entire root canal system through removal of the original root canal filling thus permitting further cleaning and re- obturation. Removal of gutta-percha and sealer becomes a critical step to gain access to the root canal system, remove necrotic tissue debris, bacteria and infected dentin.
To compare and evaluate the efficacy of manual hand Hedstrom files and two rotary retreatment file systems ProTaper Universal retreatment files and Mtwo(R) (retreatment) files in the removal of root canal filling material during root canal retreatment and the influence of the type of sealers zinc oxide eugenol and AH plus on the presence of remaining debris in the reinstrumented canals in the apical, middle and coronal third.
Sixty single rooted human premolar teeth were divided into 3 Groups of 20 teeth each Group I (20 Teeth): prepared using hand K Files, Group II (20 Teeth): prepared using ProTaper rotary system and Group III (20 Teeth): prepared using Mtwo rotary system. In Groups- IA, IIA, IIIA: (10 teeth each) Obturation was done using Zinc Oxide Eugenol sealer and gutta percha. In Groups- IB, IIB, IIIB: (10 teeth each) obturation was done with AH Plus sealer and gutta percha. All the teeth were subjected to retreatment. Groups IA and IB with Hedstrom files, Groups IIA and IIB with ProTaper retreatment files and for Groups IIIA and IIIB with Mtwo retreatment Files. The roots were longitudinally split and were observed under a stereomicroscope for remaining amount of filling material on the canal walls. Statistical analysis was done using One-way ANOVA (Analysis of variance) test and Tukey HSD Test.
Mtwo(R) files showed statistically significant difference in the removal of filling material in the apical third and ProTaper R in the coronal and apical thirds. Better cleaning efficacy was seen in canals obturated with zinc oxide eugenol sealer. Mtwo(R) files showed better removal of filling material than ProTaper R followed by Hedstrom files, even though there was no statistically significant difference.
None of the instrument group showed complete removal of the filling material. It was easier to remove zinc oxide eugenol sealer than AH plus sealer.
根管治疗在全球范围内成功率很高，已使数十亿颗牙齿免于拔除。然而，仍有治疗失败的情况，主要原因是清洁不彻底和充填不充分。在这种情况下，最保守的治疗选择是非手术再治疗。这需要通过去除原来的根管充填物重新进入整个根管系统，从而允许进一步清洁和再次充填。去除牙胶和封闭剂成为进入根管系统、清除坏死组织碎片、细菌和感染牙本质的关键步骤。
比较和评估手动Hedstrom锉与两种旋转再治疗锉系统（ProTaper Universal再治疗锉和Mtwo（R）（再治疗）锉）在根管再治疗过程中去除根管充填材料的效果，以及氧化锌丁香酚和AH plus两种封闭剂类型对再预备根管根尖、中部和冠部三分之一处残留碎屑的影响。
60颗单根人类前磨牙被分为3组，每组20颗牙齿。第一组（20颗牙齿）：用手动K锉预备；第二组（20颗牙齿）：用ProTaper旋转系统预备；第三组（20颗牙齿）：用Mtwo旋转系统预备。在IA组、IIA组、IIIA组（每组各10颗牙齿）：用氧化锌丁香酚封闭剂和牙胶进行充填。在IB组、IIB组、IIIB组（每组各10颗牙齿）：用AH Plus封闭剂和牙胶进行充填。所有牙齿均进行再治疗。IA组和IB组用Hedstrom锉，IIA组和IIB组用ProTaper再治疗锉，IIIA组和IIIB组用Mtwo再治疗锉。将牙根纵向劈开，在体视显微镜下观察根管壁上充填材料的残留量。采用单因素方差分析（ANOVA）检验和Tukey HSD检验进行统计学分析。
Mtwo（R）锉在根尖三分之一处去除充填材料方面显示出统计学上的显著差异，ProTaper R在冠部和根尖三分之一处有显著差异。用氧化锌丁香酚封闭剂充填的根管清洁效果更好。Mtwo（R）锉去除充填材料的效果优于ProTaper R，其次是Hedstrom锉，尽管没有统计学上的显著差异。
没有一个器械组能完全去除充填材料。去除氧化锌丁香酚封闭剂比AH plus封闭剂更容易。
