Saatchi Masoud, Barekatain Behnaz, Behzadian Masoumeh
Associate Professor, Department of Endodontics and Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Dent Res J (Isfahan). 2011 Winter;8(1):22-7.
The final objective of root canal therapy is to create a hermetic seal along the length of the root canal system. For this purpose, many methods and materials have been introduced. The purpose of this study was to compare the apical microleakage in a new obturation technique (true-tug-back) with two other obturation techniques (lateral condensation and chloroform dip technique).
In this in vitro study 102 single canal teeth were selected. The crowns were removed, and the canals were prepared using step-back technique. The master apical file was K-file #40. The teeth were divided into 3 experimental groups of 32 teeth. First group were obturated with lateral condensation technique and second group with chloroform dip technique and the third group with true-tug-back technique. Six teeth were used as control group. The teeth were placed in incubator at 100% humidity and 37°c for three days. The roots of the teeth were coated with two layers of nail varnish except for the apical 2 millimeter. Teeth were placed in Methylene blue 2% for one week. The teeth were sectioned vertically and the depth of maximum dye penetration for each tooth was recorded by stereomicroscope. Data were analyzed using ANOVA and Dunkan test.
The mean liner dye penetration differences between lateral condensation group (6.88 ± 4.06 mm) and chloroform dip technique group (7.16 ± 3.37 mm) were not statistically significant (P = 0.719). The differences between true-tug-back group (3.15 ± 0.52 mm) and two other groups were statistically significant (P < 0.001).
The results of this study showed that the true-tug-back technique can improve apical seal. Further studies are needed for this purpose.
根管治疗的最终目标是沿根管系统全长形成一个密闭的封填。为此，已引入了许多方法和材料。本研究的目的是比较一种新的充填技术（真回拉法）与另外两种充填技术（侧向加压法和氯仿浸渍法）的根尖微渗漏情况。
在这项体外研究中，选取了102颗单根管牙。去除牙冠，采用逐步后退技术预备根管。主尖锉为40号K锉。将牙齿分为3个实验组，每组32颗牙。第一组采用侧向加压技术充填，第二组采用氯仿浸渍法充填，第三组采用真回拉法充填。6颗牙作为对照组。将牙齿置于湿度100%、37℃的培养箱中3天。除根尖2毫米外，牙齿根部涂两层指甲油。将牙齿置于2%的亚甲蓝中一周。将牙齿垂直切开，用体视显微镜记录每颗牙齿染料最大渗透深度。数据采用方差分析和邓肯检验进行分析。
侧向加压组（6.88±4.06毫米）和氯仿浸渍法组（7.16±3.37毫米）的平均线性染料渗透差异无统计学意义（P = 0.719）。真回拉法组（3.15±0.52毫米）与其他两组的差异有统计学意义（P < 0.001）。
本研究结果表明，真回拉法可改善根尖封闭。为此还需要进一步研究。
