Department of Endodontics, School of Stomatology, Tianjin Medical University, Tianjin, China.
J Endod. 2012 Mar;38(3):381-4. doi: 10.1016/j.joen.2011.11.013. Epub 2011 Dec 22.
The objective of this study was to compare the efficacy on smear layer removal of 4 decalcifying agents: 17% ethylenediaminetetraacetic acid (EDTA), 20% citric acid, BioPure MTAD, and SmearClear.
Forty-five single-rooted human teeth were used and prepared up to ProTaper F3. After each instrumentation, 1 mL of 3% NaOCl at 60°C was irrigated for 1 minute. All the samples were randomly divided into 5 groups according to the final irrigants: 17% EDTA, 20% citric acid, BioPure MTAD, SmearClear, and 3% NaOCl (control). The smear layer removal of all groups at the apical, middle, and coronal thirds was observed under the thermal field emission scanning electron microscope.
The EDTA group was significantly more effective than the SmearClear and MTAD groups (P < .05). The efficacy of all three thirds in the EDTA, MTAD, and SmearClear groups can be arranged as coronal, middle, and apical thirds (P < .05) from excellent to poor. However, in the citric acid group, the coronal two thirds were significantly better than the apical third (P < .05), and there was no statistical significance between the coronal and middle thirds (P > .05).
The 4 decalcifying agents could effectively, but not completely, remove the smear layer, especially in the apical third. The efficacy of 17% EDTA was better than that of MTAD and SmearClear.
本研究的目的是比较 4 种脱钙剂（17%乙二胺四乙酸（EDTA）、20%柠檬酸、BioPure MTAD 和 SmearClear）对清除玷污层效果。
使用 45 颗单根人牙并制备至 ProTaper F3。每次器械预备后，用 60°C 的 1mL 3%次氯酸钠冲洗 1 分钟。所有样本根据最终冲洗液随机分为 5 组：17% EDTA、20%柠檬酸、BioPure MTAD、SmearClear 和 3%次氯酸钠（对照组）。在热场发射扫描电子显微镜下观察所有组在根尖、中间和冠三分之一处的玷污层去除情况。
EDTA 组明显优于 SmearClear 和 MTAD 组（P<0.05）。EDTA、MTAD 和 SmearClear 组的所有三个三分之一的效果可从优秀到差排列为冠三分之一、中间三分之一和根尖三分之一（P<0.05）。然而，在柠檬酸组中，冠三分之二明显优于根尖三分之一（P<0.05），且冠三分之一与中间三分之一之间无统计学意义（P>0.05）。
4 种脱钙剂均能有效但不能完全去除玷污层，尤其在根尖三分之一。17% EDTA 的效果优于 MTAD 和 SmearClear。
