Hamidi Mahmoud Reza, Mahmoudi Elham, Moghadamnia Ali Akbar, Zahedpasha Samir
Department of Endodontics, Dental School, Babol University of Medical Sciences, Babol, Iran.
Iran Endod J. 2012 Winter;7(1):15-9. Epub 2012 Mar 1.
Leakage of the root canal system is an importent consideration when placing an intracanal medicament. The aim of this in vitro study was to compare the effect of calcium hydroxide and 1% chlorhexidine gel as intracanal medicaments on tooth apical seal.
Seventy extracted, single-rooted maxillary anterior teeth were divided into the three experimental groups (n=20). All root canals were instrumented with step-back technique and divided into three groups. Group 1 had root canal dressing with calcium hydroxide; group 2 had root canal dressing with 1% chlorhexidine gel and group 3, did not receive a dressing. The roots were incubated in 100% humidity at 37°C for 7 days. After removing the dressings, all canals of the experimental groups were obturated using a cold lateral condensation technique. The root surfaces of all specimens were coated with two layers of nail varnish, except for the 2 mm surrounding the apical foramen. Apical sealing ability was assessed by dye leakage method and the specimens were examined under a stereo-microscope. Dye penetrations were measured and analyzed using ANOVA and post-hoc Tukey test.
Calcium hydroxide group had the least frequency of apical leakage at 2 mm level (0.46±0.40 mm), whilst chlorhexidine group showed the greatest apical leakage (0.86±0.42 mm). There was statistical difference between group 1 and 2 (P<0.05), but no statistical difference between group 1 and 3, or between groups 2 and 3 (P>0.05).
Intracanal calcium hydroxide medicament may decrease apical leakage of gutta-percha root fillings when AH26 sealer is used; chlorhexidine may increase the leakage.
放置根管内药物时，根管系统的渗漏是一个重要的考量因素。本体外研究的目的是比较氢氧化钙和1%洗必泰凝胶作为根管内药物对根尖封闭的影响。
70颗拔除的单根上颌前牙被分为三个试验组（n = 20）。所有根管均采用逐步后退技术进行预备，并分为三组。第1组用氢氧化钙进行根管封药；第2组用1%洗必泰凝胶进行根管封药，第3组不进行封药。将牙根在37°C、湿度100%的条件下孵育7天。去除封药后，试验组的所有根管均采用冷侧方加压技术进行充填。除根尖孔周围2mm外，所有标本的根表面均涂有两层指甲油。通过染料渗漏法评估根尖封闭能力，并在体视显微镜下检查标本。测量染料渗透情况，并采用方差分析和事后Tukey检验进行分析。
氢氧化钙组在2mm水平的根尖渗漏频率最低（0.46±0.40mm），而洗必泰组的根尖渗漏最大（0.86±0.42mm）。第1组和第2组之间存在统计学差异（P<0.05），但第1组和第3组之间以及第2组和第3组之间无统计学差异（P>0.05）。
当使用AH26封闭剂时，根管内氢氧化钙药物可能会减少牙胶尖根管充填的根尖渗漏；洗必泰可能会增加渗漏。
