School of Dentistry, The University of Queensland.
Aust Dent J. 2013 Dec;58(4):428-33. doi: 10.1111/adj.12115.
In previous studies, surfactant-containing Hypochlor brands of sodium hypochlorite showed better tissue solubilizing abilities than Milton; differences not explained by original active chlorine content or presence of surfactant. It was postulated that exhaustion of active chlorine content could explain differences. This study aimed to assess whether Milton's poorer performance was due to exhaustion of active chlorine. Parallel experiments assessed the influence of titration methods, and the presence of chlorates, on active chlorine measurements.
Time required to dissolve one or groups of 10 samples of porcine incisor pulp samples in Milton was determined. Residual active chlorine was assessed by thermometric titration. Iodometric and thermometric titration was carried out on samples of Milton. Chlorate content was also measured.
Dissolution of single and 10 pulp samples caused a mean loss of 1% and 3% respectively of active chlorine, not being proportional to tissue dissolved. Thermometric ammonium ion titration resulted in 10% lower values than iodometric titration. Chlorate accounted for much of this difference.
Depletion of active chlorine is not the reason for differences in tissue dissolving capabilities of Milton. Thermometric ammonium ion titration gives more accurate measurement of active chlorine content than iodometric titration.
在以前的研究中，含表面活性剂的次氯酸钠品牌比米尔顿更能溶解组织；这与原始有效氯含量或表面活性剂的存在无关。有人推测，有效氯含量的耗尽可以解释差异。本研究旨在评估米尔顿性能较差是否是由于有效氯耗尽。平行实验评估了滴定方法的影响以及氯酸盐的存在对有效氯测量的影响。
确定在米尔顿中溶解一个或一组 10 个猪门牙牙髓样本所需的时间。通过热滴定法评估残留有效氯。对米尔顿样本进行碘量法和热滴定法测定。还测量了氯酸盐含量。
溶解单个和 10 个牙髓样本分别导致有效氯平均损失 1%和 3%，与溶解的组织不成比例。与碘量法滴定相比，氨离子热滴定法的结果低 10%。氯酸盐对此差异有很大影响。
有效氯的消耗不是米尔顿组织溶解能力差异的原因。与碘量法滴定相比，氨离子热滴定法更能准确测量有效氯含量。
