从对多种螯合剂的评估来看，氯膦酸二钠有可能用于连续螯合。

From an assessment of multiple chelators, clodronate has potential for use in continuous chelation.

机构信息

The School of Dentistry, The University of Queensland, Herston, Qld, Australia.

Central Analytical Research Facility (CARF), Institute for Future Environments, Queensland University of Technology, Brisbane, Qld, Australia.

出版信息

Int Endod J. 2020 Jan;53(1):122-134. doi: 10.1111/iej.13213. Epub 2019 Sep 26.

DOI:10.1111/iej.13213

PMID:31483863

Abstract

AIM

To identify chelators which when mixed with sodium hypochlorite (NaOCl) are stable, exhibiting minimal loss of free available chlorine (FAC) over 80 min and to further investigate potential mixtures by assessing FAC over 18 h and the capacity to remove smear layer.

METHODOLOGY

0.25 mol L EDTA (10%), 0.25 mol L EGTA (egtazic acid), 0.25 mol L CDTA (cyclohexanediaminetetraacetic acid), 0.25 mol L DTPA (pentetic acid), 0.5 mol L ATMP (aminotri(methylene phosphonic acid)) and 1 mol L HPAA, (hydroxyphosphonoacetic acid), all at alkaline pH, were mixed equally with 5% NaOCl. 0.5 mol L alkaline clodronate and 0.5 mol L Na etidronate (15%) were mixed equally with 10% NaOCl. For all mixtures, the pH and temperature were measured over 80 min and additionally for the clodronate mixture over 18 h. Iodometric titration was used to measure the FAC of all mixtures except for HPAA. The following were compared with respect to their ability to remove smear layer: 1 mol L clodronate + 10% NaOCl, 0.5 mol L clodronate + 10% NaOCl, 1 mol L etidronate + 10% NaOCl, 0.5 mol L clodronate + 10% NaOCl and the sequences 5% NaOCl/17% EDTA/5% NaOCl and 5% NaOCl/17% EDTA. The area fraction occupied by open dentinal tubules as a percentage of the total area (% AF) from scanning electron microscopy micrographs was calculated using Image J. The results were statistically analysed with alpha set at 0.05.

RESULTS

Compared to its control, the mixture 0.5 mol L clodronate + 10% NaOCl lost no FAC over 18 h (P > 0.05). The FAC of 0.25 mol L CDTA mixed with 5% NaOCl fell to 96%, 92%, 75% and 4.9% at 20, 40, 60 and 80 min, respectively. Temperature rises were observed in all cases except in the etidronate and clodronate mixtures. Only in the clodronate mixture did the pH remain above pH 12 for the whole experiment. Although smear layer was removed, the % AF in 1 mol L clodronate + 10% NaOCl, 0.5 mol L clodronate + 10% NaOCl, 1 mol L etidronate + 10% NaOCl was less than for 0.5 mol L etidronate + 10% NaOCl and 5% NaOCl/17% EDTA/5% NaOCl and 5% NaOCl/17% EDTA.

CONCLUSION

Alkaline 0.5 mol L clodronate mixed equally with 10% NaOCl has potential for use in continuous chelation, based on this assessment of stability and smear layer removal. Further research is needed to establish its efficacy and safety.

摘要

目的

鉴定与次氯酸钠（NaOCl）混合时稳定的螯合剂，在 80 分钟内最小限度地损失游离有效氯（FAC），并通过评估 18 小时内的 FAC 和去除玷污层的能力进一步研究潜在的混合物。

方法

0.25mol/L EDTA（10%）、0.25mol/L EGTA（依地酸）、0.25mol/L CDTA（环己二胺四乙酸）、0.25mol/L DTPA（戊二胺四乙酸）、0.5mol/L ATMP（氨基三甲叉膦酸）和 1mol/L HPAA（羟基膦基乙酸），均在碱性 pH 值下，与 5% NaOCl 等体积混合。0.5mol/L 碱性氯膦酸和 0.5mol/L 依替膦酸钠（15%）与 10% NaOCl 等体积混合。对于所有混合物，在 80 分钟内测量 pH 值和温度，并且对于氯膦酸盐混合物还在 18 小时内测量。除 HPAA 外，所有混合物均使用碘量滴定法测量 FAC。以下是与去除玷污层能力相关的比较：1mol/L 氯膦酸+10% NaOCl、0.5mol/L 氯膦酸+10% NaOCl、1mol/L 依替膦酸钠+10% NaOCl、0.5mol/L 氯膦酸+10% NaOCl 和序列 5% NaOCl/17% EDTA/5% NaOCl 和 5% NaOCl/17% EDTA。使用 Image J 计算扫描电子显微镜照片中开放牙本质小管的总面积的百分比（%AF）。使用 alpha 设定为 0.05 进行统计学分析。

结果

与对照相比，0.5mol/L 氯膦酸+10% NaOCl 混合物在 18 小时内没有损失 FAC（P>0.05）。0.25mol/L CDTA 与 5% NaOCl 混合的 FAC 在 20、40、60 和 80 分钟时分别降至 96%、92%、75%和 4.9%。除依替膦酸钠和氯膦酸盐混合物外，所有情况下都观察到温度升高。只有在氯膦酸盐混合物中，整个实验过程中 pH 值均保持在 pH 12 以上。虽然去除了玷污层，但 1mol/L 氯膦酸+10% NaOCl、0.5mol/L 氯膦酸+10% NaOCl、1mol/L 依替膦酸钠+10% NaOCl 的%AF 低于 0.5mol/L 依替膦酸钠+10% NaOCl 和 5% NaOCl/17% EDTA/5% NaOCl 和 5% NaOCl/17% EDTA。