不同氢氧化钙制剂在根尖周区氢氧离子扩散效能的研究

Study on the apical diffusion of hydroxyl ion of calcium hydroxide in immature teeth: An in vitro study

目的:比较3种不同氢氧化钙制剂在年轻恒牙根尖部OH-扩散的能力。方法:选取正畸减数拔除的人前磨牙140个,常规根管预备后随机分为3个实验组(每组42个样本)和1个空白对照组(14个样本)。3个实验组分别用氢氧化钙水糊剂、Metapex糊剂和Vitapex糊剂充填根管,空白对照组不做充填。分别于充填后1 h、24 h、7 d、14 d、1个月、3个月对各组根尖周区局部pH值进行测量。采用SPSS13.0软件以重复测量方差分析法进行统计分析。结果:与对照组相比,3种糊剂均能在牙根尖周区形成碱性环境,局部pH值随时间逐步上升(P<0.05)。横向比较中,Vitapex糊剂局部碱化能力低于另2组(P<0.05);7 d内,氢氧化钙水糊剂碱化效果最为明显(P<0.05);从14 d开始,氢氧化钙水糊剂与Metapex糊剂在根尖周部所形成的碱性环境相当(P>0.05)。结论:氢氧化钙水糊剂、Metapex糊剂能在根尖周区更为有效地形成强碱性环境,较之Vitapex糊剂更适于作为根尖诱导成形剂。

AIM ： To access the apical diffusion of hydroxyl ion of three non - setting calcium hydroxide preparations filled in open - ended canal of immature teeth at regular intervals in a simulated periapical environment in vitro. METHODS： 140 humans immature premolars extracted for orthodontics were randomly assigned to four groups. Teeth filled with calcium hydroxide paste（CH） , Metapex and Vitapex were used as three experimental groups. Unfilled teeth were used as the controls. Then the teeth were placed in individual plastic vials, each containing 2.0 mL distilled water. Measurements of pH value in the medium were performed after lh, 24h, 7d, 14d, lmonth and 3month. The data was analyzed with repeated measures using SPSS 13.0 software, and a significant level was setup （P 〈0.05 ）. RESULTS： The alkalinity of three experimental groups continued to increase over the 3 - month observation period. All the experimental groups had a significantly higher pH in comparison to the control at all the time intervals （P 〈 0.05 ）. In the first 7 days, the pH values of CH were higher than the Metapex and Vitapex. In the following time intervals, no significant difference appeared between Metapex and CH, but the difference was still statistically significant between CH and Vitapex, Metapex and Vitapex（P 〈 0.05 ）. The pH values for CH and Metapex were higher than Vitapex. CONCLUSION： It may be inferred that the calcium hydroxide paste and Metapex were more effective than the Vitapcx in the alkalizing process, and might he the better preparations for apexification.