Kim S K, Kim Y O
Department of Conservative Dentistry, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
Int Endod J. 2002 Jul;35(7):623-8. doi: 10.1046/j.1365-2591.2002.00539.x.
The aim of this study was to determine the influence of calcium hydroxide intracanal medication and various techniques for its removal on the sealing ability of gutta-percha root fillings with a zinc oxide-eugenol sealer.
Eighty extracted mature human mandibular molar roots were divided into three groups of similar root-canal configuration. Calcium hydroxide paste was made by mixing calcium hydroxide powder with distilled water at a powder to liquid ratio of 1:1.25. After root canals were prepared and enlarged to a minimum of size 30 with the Profile 0.06 system, calcium hydroxide paste was placed in the canals of two groups, but no medication was placed in the control group. The intracanal calcium hydroxide was removed with two different techniques, 1 week after medication: K-files one size larger than the master apical file (MAF) were used with 2.5% NaOCl and 15% EDTA solutions in one group, whilst K-files the same size as the MAF were used with 2.5% NaOCl solution in another group. Canals were obturated with gutta-percha and Tubli-Seal cement using the lateral condensation technique. The apical sealing-ability was assessed by dye leakage and cross-sections of the specimens were examined under a stereomicroscope. The dye-penetration level was measured and analyzed using Fisher's exact test and Duncan's multiple range test.
The calcium hydroxide-medicated groups showed significantly more dye leakage than the non-medicated control group (P < 0.05). However, there was no significant difference between the two calcium hydroxide-medicated groups (P > 0.05). The stereomicroscopic views showed a relatively uneven and thicker layer of sealer in the calcium hydroxide-medicated groups.
Calcium hydroxide intracanal medication may increase apical leakage of gutta-percha root fillings when a zinc oxide-eugenol sealer is used.
本研究旨在确定氢氧化钙根管内用药及其不同去除技术对使用氧化锌丁香酚封闭剂的牙胶尖根管充填物封闭能力的影响。
将80颗拔除的成熟人下颌磨牙牙根分为三组，根管形态相似。将氢氧化钙粉末与蒸馏水按粉末与液体1:1.25的比例混合制成氢氧化钙糊剂。使用Profile 0.06系统将根管预备并扩大至至少30号，两组根管内放置氢氧化钙糊剂，对照组不进行药物处理。用药1周后，采用两种不同技术去除根管内的氢氧化钙：一组使用比主尖锉（MAF）大一号的K锉配合2.5%次氯酸钠和15%乙二胺四乙酸（EDTA）溶液，另一组使用与MAF相同尺寸的K锉配合2.5%次氯酸钠溶液。采用侧向加压技术用牙胶尖和Tubli-Seal粘固剂对根管进行充填。通过染料渗漏评估根尖封闭能力，并在体视显微镜下检查标本的横断面。使用Fisher精确检验和Duncan多重极差检验测量并分析染料渗透水平。
氢氧化钙用药组的染料渗漏明显多于未用药的对照组（P < 0.05）。然而，两个氢氧化钙用药组之间无显著差异（P > 0.05）。体视显微镜观察显示，氢氧化钙用药组的封闭剂层相对不均匀且更厚。
当使用氧化锌丁香酚封闭剂时，氢氧化钙根管内用药可能会增加牙胶尖根管充填物的根尖渗漏。
