Vidhya Nirmal, Karthikeyan Balasubramanian Saravana, Velmurugan Natanasabapathy, Abarajithan Mohan, Nithyanandan Sivasankaran
Department of Conservative Dentistry and Endodontics, Meenakshi Ammal Dental College and Hospital, Meenakshi University, Chennai, Tamil Nadu, India.
Department of Chemistry, College of Engineering, Anna University, Guindy, Chennai, Tamil Nadu, India.
Dent Res J (Isfahan). 2014 May;11(3):395-9.
Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX.
SAMPLES WERE DIVIDED INTO EIGHT EXPERIMENTAL GROUPS: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test.
In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours.
Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.
局部麻醉溶液盐酸利多卡因（含或不含肾上腺素）与根管冲洗剂如次氯酸钠（NaOCl）、乙二胺四乙酸（EDTA）和氯己定（CHX）之间的相互作用此前尚未被研究。因此，本体外研究的目的是评估2%盐酸利多卡因（含或不含肾上腺素）与常用根管冲洗剂NaOCl、EDTA和CHX之间的化学相互作用。
样本分为八个实验组：第一组——盐酸利多卡因（含肾上腺素）/3% NaOCl，第二组——盐酸利多卡因（含肾上腺素）/17% EDTA，第三组——盐酸利多卡因（含肾上腺素）/2% CHX，第四组——盐酸利多卡因（不含肾上腺素）/3% NaOCl，第五组——盐酸利多卡因（不含肾上腺素）/17% EDTA，第六组——盐酸利多卡因（不含肾上腺素）/2% CHX，以及两个对照组：第七组——盐酸利多卡因（含肾上腺素）/去离子水和第八组——盐酸利多卡因（不含肾上腺素）/去离子水。将各实验组的相应溶液按等比例（各1毫升）混合，观察是否有沉淀形成。然后通过核磁共振光谱（NMR）分析所形成沉淀的化学成分，并用重氮化试验进行确认。
在第一组和第四组中，混合相应溶液后，所有样本中均观察到白色沉淀，15分钟后沉淀颜色变为红棕色。然后通过核磁共振光谱对该沉淀进行分析，观察到其为2,6 - 二甲基苯胺，一种已报道的有毒化合物。直到2小时，第二组、第三组、第五组和第六组以及对照组第七组和第八组在各自样本中均未观察到沉淀形成。
盐酸利多卡因（含或不含肾上腺素）与NaOCl之间的相互作用显示形成了含有有毒化合物2,6 - 二甲基苯胺的沉淀。
