Kumar Satish, Deshpande S J, Rao Ajay Singh
Department of Conservative Dentistry and Endodontics, HKE's S N Institute of Dental Sciences and Research, Gulbarga, Karnataka, India.
Indian J Dent Res. 2011 Sep-Oct;22(5):622-6. doi: 10.4103/0970-9290.93445.
The aim of the study was to compare the conventional ThermaFil obturation technique and ThermaFil obturation with mineral trioxide aggregate (MTA) as an apical barrier, with regard to apical sealing and extrusion.
Twenty extracted human canines were instrumented using a crown-down technique and divided into two groups. The experimental group was obturated using ThermaFil obturation with MTA as an apical barrier and the control group was obturated using the conventional ThermaFil obturation technique. AH Plus sealer was used in both the groups. Apical extrusion was recorded. Teeth of both the groups were coated with nail polish, except for the apical 3 mm. After 24 h, they were suspended in black India ink for 48 h. Canines were decalcified, rendered transparent, and linear dye penetration was measured under ×40 stereomicroscope.
There was a significant extrusion noticed in conventional ThermaFil obturation technique. Frequency of extrusion of sealer and/or gutta-percha was supposed to be evaluated using χ² test, but since the values of the samples of ThermaFil plus MTA group were zero, statistical analysis could not be conducted, whereas linear dye leakage was calculated with Mann-Whitney U test because the distribution was abnormal.
Although ThermaFil plus MTA group showed microleakage, extrusion of sealer and the core material was prevented in comparison with conventional ThermaFil obturation technique. It is advantageous to use MTA as an apical plug as there is no fear of apical extrusion and the root canal system can then be packed three dimensionally against this barrier using any thermoplasticized gutta-percha obturation technique.
本研究旨在比较传统热牙胶充填技术与以矿物三氧化物凝聚体（MTA）作为根尖屏障的热牙胶充填技术在根尖封闭性和充填材料挤出方面的差异。
选取20颗拔除的人犬齿，采用冠向深入技术进行根管预备，并分为两组。实验组采用以MTA作为根尖屏障的热牙胶充填，对照组采用传统热牙胶充填技术。两组均使用AH Plus封闭剂。记录根尖充填材料的挤出情况。两组牙齿除根尖3mm外均涂指甲油。24小时后，将其浸泡在黑色印度墨水中48小时。犬齿脱钙、透明化后，在×40体视显微镜下测量线性染料渗透情况。
传统热牙胶充填技术中观察到明显的充填材料挤出。封闭剂和/或牙胶尖的挤出频率本应使用χ²检验进行评估，但由于热牙胶加MTA组样本值为零，无法进行统计分析，而线性染料渗漏采用Mann-Whitney U检验计算，因为其分布异常。
虽然热牙胶加MTA组显示有微渗漏，但与传统热牙胶充填技术相比，可防止封闭剂和核心材料的挤出。使用MTA作为根尖堵塞物具有优势，因为无需担心根尖充填材料挤出，然后可以使用任何热塑牙胶充填技术对根管系统进行三维充填以抵住该屏障。
