Hariharan V S, Nandlal B, Srilatha K T
Department of Pedodontics & Preventive Dentistry, Sree Balaji Dental College & Hospital, Chennai, India.
J Indian Soc Pedod Prev Dent. 2010 Oct-Dec;28(4):271-7. doi: 10.4103/0970-4388.76157.
The purpose of this in-vitro study is to determine the efficacy of various irrigants in removing the smear layer in primary teeth root canals after hand instrumentation.
The present study consisted of 30 human primary incisors which were sectioned at the cementoenamel junction horizontally. The specimens were divided randomly into four experimental and one control group having six teeth each and each group was treated with the specific irrigant. 5.25% NaOCl, 5.25% NaOCl + 10% EDTA, 6% citric acid, 2% chlorhexidine, saline (control) were the irrigants evaluated for efficacy in removal of smear layer. The specimens were split along the longitudinal axis using a chisel after placing superficial grooves in cementum not extending to the root canal. The exposed surface was subjected to scanning electron microscopic analysis to reveal the efficacy of irrigants in removal of smear layer. The representative areas were evaluated twice at 15 days interval by a single evaluator. The scale for the smear layer removal by Rome et al was modified and used in the present study.
The pictures from the scanning electron microscopy showed that among the tested irrigants, citric acid has the best efficacy to remove the smear layer without altering the normal dentinal structures, which was supported by the lowest mean smear scores. The pictures from the 10%EDTA + 5.25% sodium hypochlorite group showed that even though it removed the smear layer, it adversely affected the dentine structure. SEM pictures of the other groups like sodium hypochlorite, chlorhexidine revealed that these irrigants does not have the capacity to remove the smear layer in primary teeth.
The results of the present study clearly indicate the superior efficacy of 6% citric acid than the other tested irrigants on removing the smear layer in primary teeth root canals.
本体外研究旨在确定不同冲洗剂在手动器械预备后去除乳牙根尖根管内玷污层的效果。
本研究选取30颗人类乳切牙，在牙骨质釉质界水平进行横切。将标本随机分为四个试验组和一个对照组，每组六颗牙，每组用特定的冲洗剂处理。评估5.25%次氯酸钠、5.25%次氯酸钠+10%乙二胺四乙酸（EDTA）、6%柠檬酸、2%氯己定、生理盐水（对照组）去除玷污层的效果。在牙骨质上制备不延伸至根管的浅沟后，用凿子沿纵轴将标本劈开。对暴露的表面进行扫描电子显微镜分析，以揭示冲洗剂去除玷污层的效果。由一名评估者在15天的间隔内对代表性区域进行两次评估。本研究修改并采用了Rome等人的玷污层去除评分标准。
扫描电子显微镜图像显示，在所测试的冲洗剂中，柠檬酸在不改变正常牙本质结构的情况下，去除玷污层的效果最佳，这得到了最低平均玷污层评分的支持。10%EDTA+5.25%次氯酸钠组的图像显示，尽管它去除了玷污层，但对牙本质结构有不利影响。次氯酸钠、氯己定等其他组的扫描电子显微镜图像显示，这些冲洗剂没有去除乳牙根管内玷污层的能力。
本研究结果清楚地表明，6%柠檬酸在去除乳牙根尖根管内玷污层方面比其他测试冲洗剂具有更好的效果。
