de Pellegrin Sidnei Flores, Pauletto Guilherme, Carlotto Israel Bangel, Mendes Ana Luiza Garcia, de Azevedo Mello Paola, Bier Carlos Alexandre Souza
Graduate Program in Dentistry, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
MSciD and PhD Post-Graduate Program in Oral Science, Faculty of Dentistry, Federal University of Santa Maria (UFSM), Santa Maria, Rio Grande do Sul State, Brazil.
J Endod. 2023 Jul;49(7):894-900. doi: 10.1016/j.joen.2023.05.003. Epub 2023 May 12.
This study aimed to identify possible products resulting from chemical interactions between calcium hypochlorite (Ca[OCl]) and other irrigants for endodontic use using electrospray ionization quadrupole time-of-flight mass spectrometry.
The 5.25% Ca(OCl) was associated with either 70% ethanol solution, distilled water, saline solution (0.9% sodium chloride), 5% sodium thiosulfate, 10% citric acid, 17% ethylenediaminetetraacetic acid (EDTA), or 2% chlorhexidine (CHX). The reaction ratio was 1:1 and the products obtained were analyzed by electrospray ionization quadrupole time-of-flight mass spectrometry.
The interactions between Ca(OCl) and CHX generated an orange-brown precipitate, without identification of para-chloroaniline and between Ca(OCl) and sodium thiosulfate, a milky-white precipitate. Furthermore, when the oxidizing agent was associated with EDTA and citric acid, chlorine gas was released. As for the other associations, 70% ethanol, distilled water, and saline solution, no precipitation or gas release occurred.
The orange-brown precipitate occurs due to the chlorination of guanidine nitrogens, and the milky-white precipitate is due to the partial neutralization of the oxidizing agent. The release of chlorine gas occurs due to the low pH of the mixture, which results in the rapid formation and decomposition of chlorine. In this context, an intermediate rinsed with distilled water, saline solution, and ethanol between Ca(OCl) and CHX, citric acid, and EDTA seems to be appropriate to prevent the formation of by-products when these irrigants need to be used in the canal. Furthermore, if it is necessary to use sodium thiosulfate, a larger volume of the solution must be used compared to that used for the oxidizing solution.
本研究旨在利用电喷雾电离四极杆飞行时间质谱法，确定次氯酸钙（Ca[OCl]）与其他牙髓治疗用冲洗剂之间化学相互作用可能产生的产物。
将5.25%的Ca(OCl)与70%乙醇溶液、蒸馏水、盐溶液（0.9%氯化钠）、5%硫代硫酸钠、10%柠檬酸、17%乙二胺四乙酸（EDTA）或2%氯己定（CHX）混合。反应比例为1:1，所得产物用电喷雾电离四极杆飞行时间质谱法进行分析。
Ca(OCl)与CHX相互作用产生橙棕色沉淀，未鉴定出对氯苯胺；Ca(OCl)与硫代硫酸钠相互作用产生乳白色沉淀。此外，当氧化剂与EDTA和柠檬酸混合时，会释放出氯气。至于其他组合，即70%乙醇、蒸馏水和盐溶液，则未发生沉淀或气体释放。
橙棕色沉淀是由于胍基氮的氯化作用，乳白色沉淀是由于氧化剂的部分中和作用。氯气的释放是由于混合物的低pH值，导致氯的快速形成和分解。在这种情况下，当需要在根管中使用这些冲洗剂时，在Ca(OCl)与CHX、柠檬酸和EDTA之间用蒸馏水、盐溶液和乙醇进行中间冲洗，似乎适合防止副产物的形成。此外，如果需要使用硫代硫酸钠，与氧化剂溶液相比，必须使用更大体积的该溶液。
