Niu W, Yoshioka T, Kobayashi C, Suda H
Pulp Biology and Endodontics, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Int Endod J. 2002 Nov;35(11):934-9. doi: 10.1046/j.1365-2591.2002.00594.x.
The purpose of this in vitro study was to examine dentinal erosion caused by final irrigation with EDTA and NaOCl.
Twenty-five single-rooted human teeth were instrumented with rotary nickel-titanium Series 29 Profile Instruments. The teeth were divided into five groups and subjected to final irrigation as follows: group A, irrigated with 6% NaOCl (3 mL) for 2 min; group B, 15% EDTA (3 mL) for 1 min; group C, 15% EDTA (3 mL) for 1 min, followed by 6% NaOCl (3 mL) for 2 min; group D, 15% EDTA (3 mL) for 3 min and group E, 15% EDTA (3 mL) for 3 min, followed by 6% NaOCl (3 mL) for 2 min. Photomicrographs of dentinal walls were produced using a scanning electron microscope (3000 x) at 1, 3 and 6 mm from the apex. The amount of debris and dentinal tubule diameter were evaluated, and values were statistically analysed using one-way ANOVA and Fisher's PLSD test.
When the root canal was irrigated with 15% EDTA alone, the dentine had a smooth and plane appearance, and dentinal tubule orifices were regular and separated. When the root canal was irrigated with EDTA followed by NaOCL the dentine was eroded and the dentinal tubule orifices were irregular and rough. Dentinal tubule diameter increased to 3.43 +/- 0.23 microm in group C and to 3.93 +/- 0.44 microm in group E. Significant differences were observed between groups B and C, and between groups D and E (P < 0.05). However, more debris was removed by irrigation with EDTA followed by NaOCl than with EDTA alone (P < 0.05).
Final irrigation with 6% NaOCl accelerates dentinal erosion following treatment with 15% EDTA.
本体外研究旨在检测乙二胺四乙酸（EDTA）和次氯酸钠（NaOCl）进行最终冲洗时所导致的牙本质侵蚀情况。
使用旋转镍钛29型根管器械对25颗单根人牙进行预备。将牙齿分为五组并进行如下最终冲洗：A组，用6% NaOCl（3 mL）冲洗2分钟；B组，用15% EDTA（3 mL）冲洗1分钟；C组，先用15% EDTA（3 mL）冲洗1分钟，接着用6% NaOCl（3 mL）冲洗2分钟；D组，用15% EDTA（3 mL）冲洗3分钟；E组，先用15% EDTA（3 mL）冲洗3分钟，接着用6% NaOCl（3 mL）冲洗2分钟。使用扫描电子显微镜（放大3000倍）在距根尖1、3和6毫米处拍摄牙本质壁的显微照片。评估碎屑量和牙本质小管直径，并使用单因素方差分析和Fisher最小显著差异检验对数据进行统计学分析。
单独用15% EDTA冲洗根管时，牙本质表面光滑平整，牙本质小管口规则且分开。先用EDTA冲洗根管再用NaOCl冲洗时，牙本质被侵蚀，牙本质小管口不规则且粗糙。C组牙本质小管直径增加到3.43±0.23微米，E组增加到3.93±0.44微米。B组与C组之间以及D组与E组之间观察到显著差异（P < 0.05）。然而，先用EDTA冲洗再用NaOCl冲洗比单独用EDTA冲洗能去除更多的碎屑（P < 0.05）。
用6% NaOCl进行最终冲洗会加速在15% EDTA处理后出现的牙本质侵蚀。
