Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
Int Endod J. 2013 Apr;46(4):332-8. doi: 10.1111/j.1365-2591.2012.02119.x. Epub 2012 Sep 13.
To evaluate, by scanning electron microscopy (SEM), the efficacy of smear layer removal using chitosan compared with different chelating agents, and to quantify, by atomic absorption spectrophotometry with flame (AASF), the concentration of calcium ions in these solutions after irrigation.
The root canals of twenty-five canines were prepared using a crown-down technique and irrigated with 1% sodium hypochlorite. The teeth were randomly divided into groups (n = 5), according to the type of final irrigation: 15% EDTA, 0.2% chitosan, 10% citric acid, 1% acetic acid and control (without final irrigation). The total volume of each chelating solution was collected from the canals and analysed by AASF for quantification of calcium ions in the solutions. Then, the roots were split longitudinally and examined by SEM for evaluation of smear layer removal in the middle and apical thirds. Cleaning scores were attributed and analysed statistically using the Kruskal-Wallis and Dunn tests. The AASF data were analysed by one-way anova and Tukey-Kramer test. A significant level of α = 0.05 was adopted.
15% EDTA, 0.2% chitosan and 10% citric acid had similar smear layer removal capacity with a significant difference (P < 0.05) from 1% acetic acid and the control group. There was no significant difference (P > 0.05) between the smear layer remaining in the middle and apical thirds. The highest calcium ion concentration was observed with 15% EDTA (121.80 ± 5.13) and 0.2% chitosan (104.13 ± 19.23), with no significant difference. The lowest calcium ion concentration was obtained with 1% acetic acid (25.62 ± 7.68), whilst 10% citric acid (70.38 ± 11.15) had intermediate results, differing significantly from the other solutions (P < 0.01).
15% EDTA, 0.2% chitosan and 10% citric acid effectively removed smear layer from the middle and apical thirds of the root canal. 15% EDTA and 0.2% chitosan were associated with the greatest effect on root dentine demineralization, followed by 10% citric acid and 1% acetic acid.
通过扫描电子显微镜（SEM）评估壳聚糖与不同螯合剂相比去除玷污层的效果，并通过火焰原子吸收光谱法（AASF）定量分析这些溶液在冲洗后的钙离子浓度。
使用冠向下技术对 25 颗犬牙的根管进行预备，并用 1%次氯酸钠冲洗。根据最终冲洗类型将牙齿随机分为 5 组（n=5）：15% EDTA、0.2%壳聚糖、10%柠檬酸、1%乙酸和对照组（无最终冲洗）。从每个螯合溶液的根管中收集总容量，并通过 AASF 分析溶液中钙离子的定量。然后，将根部分为纵向两半，通过 SEM 检查中、根尖三分之一处的玷污层去除情况。对清洁评分进行赋值，并使用 Kruskal-Wallis 和 Dunn 检验进行统计学分析。AASF 数据采用单因素方差分析和 Tukey-Kramer 检验进行分析。采用α=0.05 的显著水平。
15% EDTA、0.2%壳聚糖和 10%柠檬酸的清除玷污层能力相似，与 1%乙酸和对照组相比有显著差异（P<0.05）。中、根尖三分之一处的玷污层残留无显著差异（P>0.05）。15% EDTA（121.80±5.13）和 0.2%壳聚糖（104.13±19.23）的钙离子浓度最高，无显著差异。1%乙酸的钙离子浓度最低（25.62±7.68），而 10%柠檬酸（70.38±11.15）的结果居中，与其他溶液有显著差异（P<0.01）。
15% EDTA、0.2%壳聚糖和 10%柠檬酸可有效清除根管中、根尖三分之一处的玷污层。15% EDTA 和 0.2%壳聚糖对牙本质脱矿的影响最大，其次是 10%柠檬酸和 1%乙酸。
