Department of Endodontics, Dental School, Shiraz University of Medical Sciences, Ghasrdasht Street, 71956-15878, Shiraz, Iran.
BMC Oral Health. 2020 Nov 12;20(1):326. doi: 10.1186/s12903-020-01320-2.
This study aims to evaluate the ability of sodium thiosulfate (STS) to neutralize the adverse effect of sodium hypochlorite (NaOCl) on dentin micro-hardness.
Fifty single-rooted teeth were longitudinally sectioned. The samples divided into a control and four sample groups (n = 20). All the samples were immersed in different solutions as follows, Control: Normal saline for 15 min, G1and G2: 2.5% NaOCl for 15 min, G3: 2.5% NaOCl for 15 min, followed by 5% STS for 10 min, G4: Normal saline for 15 min followed by 5% STS for 10 min. All groups except G1 incubated for one week before the test. The micro-hardness of samples was measured. Data were analyzed using the Kruskal-Wallis test for pairwise comparisons. A p value < 0.05 was considered significant.
All groups showed a significant decrease in the micro-hardness value compared with the control group. NaOCl for one week (G2) reduced the micro-hardness of dentine compared with samples, tested immediately after immersion in NaOCl (G1) (p < 0.05). NaOCl alone (G2) or treated with STS (G3) resulted in a significant decrease in micro-hardness compared with the STS group (G4) (p < 0.05).
STS as a neutralizing agent could not prevent the dentin micro-hardness downturn caused by NaOCl.
本研究旨在评估硫代硫酸钠（STS）中和次氯酸钠（NaOCl）对牙本质微硬度的不良影响的能力。
将 50 颗单根牙纵向切片。样本分为对照组和四个样本组（n=20）。所有样本均浸入以下不同溶液中：对照组：生理盐水 15 分钟；G1 和 G2：2.5% NaOCl 15 分钟；G3：2.5% NaOCl 15 分钟，继用 5% STS 10 分钟；G4：生理盐水 15 分钟，继用 5% STS 10 分钟。除 G1 组外，所有组均在测试前孵育一周。测量样本的微硬度。采用 Kruskal-Wallis 检验进行两两比较，p 值<0.05 为差异有统计学意义。
与对照组相比，所有组的微硬度值均显著降低。与即刻浸泡在 NaOCl 中的样本（G1）相比，一周的 NaOCl（G2）降低了牙本质的微硬度（p<0.05）。单独使用 NaOCl（G2）或用 STS 处理（G3）与 STS 组（G4）相比，微硬度显著降低（p<0.05）。
作为中和剂，STS 不能预防 NaOCl 引起的牙本质微硬度下降。
