Department of Conservative Dentistry and Endodontics, SRM Dental College, Ramapuram, Tamil Nadu, India.
Eur Endod J. 2021 Apr;6(1):117-121. doi: 10.14744/eej.2020.52523. Epub 2021 Jan 26.
Local anaesthetic solution that is commonly employed for supplemental intrapulpal injection (IPI) may routinely come in contact with subsequently used sodium hypochlorite (NaOCl) during endodontic treatment of symptomatic irreversible pulpitis cases. This in vitro study investigated the available free active chlorine (FAC) content of 3% NaOCl after mixing with 2% lignocaine hydrochloride with adrenaline (LA) solution in three different proportions using iodometric titration analysis.
Aliquots of 3% NaOCl (control) in different measures (30 mL, 27 mL, 21 mL and 15 mL) served as the effective concentrate of various proportions of NaOCl admixed with the test solutions, i.e., demineralised water (DM) and LA. The mixed aliquots containing NaOCl-DM and NaOCl-LA combination solutions admixed in various proportions (9: 1, 7: 3 and 1: 1 w/v) respectively served as the experimental groups. Iodometric titration was performed to determine the FAC of each independent solution.The results were then evaluated using one-way ANOVA and Tukey's post hoc analysis to determine the differences between various groups and amongst the individual admixtures. The level of significance was set at P<0.05.
Inter-group comparisons revealed statistically significant differences (P<0.05) between all the test groups. An intra-group analysis revealed significant differences (P<0.05) in group 2, whereas no differences (P>0.05) were observed in group 3. Further, there was a dose dependent reduction in FAC content in both the experimental groups with lowest FAC values were observed in 1: 1 solution admixtures followed by 7: 3 and 9: 1 proportions.
There was a significant reduction in NaOCl FAC content when admixed with lignocaine HCl even in small proportions. Hence, adequate measures should be taken to remove the residual LA from the pulpal space, before the use of NaOCl after IPI administration.
在治疗有症状的不可复性牙髓炎的病例中，局部麻醉剂溶液（通常用于补充牙髓内注射（IPI））可能会在根管治疗过程中与随后使用的次氯酸钠（NaOCl）常规接触。本体外研究使用碘量滴定分析，调查了在三种不同比例下，2%盐酸利多卡因肾上腺素（LA）溶液与 3% NaOCl 混合后，3% NaOCl 的游离有效氯（FAC）含量。
用不同量（30ml、27ml、21ml 和 15ml）的 3% NaOCl（对照）作为各种比例的 NaOCl 的有效浓缩液，与测试溶液，即去离子水（DM）和 LA 混合。分别含有不同比例的 NaOCl-DM 和 NaOCl-LA 混合溶液（分别为 9:1、7:3 和 1:1w/v）的混合等分试样作为实验组。进行碘量滴定以确定每种独立溶液的 FAC。然后使用单因素方差分析和 Tukey 事后分析评估结果，以确定各组之间和各混合物之间的差异。显著性水平设为 P<0.05。
组间比较显示所有测试组之间存在统计学差异（P<0.05）。组内分析显示组 2 有显著差异（P<0.05），而组 3 无差异（P>0.05）。此外，两组的 FAC 含量均呈剂量依赖性降低，最低 FAC 值出现在 1:1 溶液混合物中，其次是 7:3 和 9:1 比例。
即使混合少量的盐酸利多卡因，也会导致 NaOCl 的 FAC 含量显著降低。因此，在 IPI 给药后使用 NaOCl 之前，应采取适当措施从牙髓腔中清除残留的 LA。
