Vianna Morgana Eli, Zilio Danila M, Ferraz Caio Cezar Randi, Zaia Alexandre Augusto, de Souza-Filho Francisco José, Gomes Brenda Paula Figueiredo de Almeida
Eastman Dental Institute, Unit of Endodontology, University College London, London, UK.
Braz Dent J. 2009;20(5):382-8. doi: 10.1590/s0103-64402009000500005.
The purpose of this in vitro study was to measure the concentration of hydrogen ions (pH) of calcium hydroxide [(Ca(OH)2] pastes combined with different vehicles over 7 periods of time. The Ca(OH)2 was manipulated with the following vehicles: i: sterile water; ii: iodoform plus sterile water; iii: local anesthetics (Lydocaine 2% with 1: 100,000 epinephrine); iv: polyethyleneglycol; v: glycerin; vi: 2.0% chlorhexidine gel; vii: camphorated paramonochlorophenol (CMCP); viii: (CMCP) + glycerin; and ix: polyethyleneglycol plus CMCP. The pastes were made on a glass plate to toothpaste consistency and the pH was measured at the following times: 5 min, 1, 24, 48 h; 7, 14 and 28 days. The data were statistically analyzed (Kruskal-Wallis at p<0.05). At 5 min, 1 and 24 h, the pH of all tested pastes ranged from 13.05 to 11.16. At 48 h and 7 days the pH of all tested pastes ranged from 11.66 to 8.92. At 14 and 28 days almost all pastes had pH means lower than 10. In conclusion, the mean pH of all tested calcium hydroxide pastes decreased with the time. Pastes made with aqueous vehicles (especially with sterile water), followed by oily vehicles (especially with CMCP + glycerin), held the highest pH means over the periods of time tested.
本体外研究的目的是测量在7个时间段内，与不同赋形剂混合的氢氧化钙[Ca(OH)₂]糊剂中的氢离子浓度（pH值）。氢氧化钙与以下赋形剂混合使用：i：无菌水；ii：碘仿加无菌水；iii：局部麻醉剂（2%利多卡因加1:100,000肾上腺素）；iv：聚乙二醇；v：甘油；vi：2.0%氯己定凝胶；vii：樟脑对氯苯酚（CMCP）；viii：（CMCP）+甘油；ix：聚乙二醇加CMCP。将糊剂在玻璃板上调制至牙膏状稠度，并在以下时间点测量pH值：5分钟、1小时、24小时、48小时、7天、14天和28天。对数据进行统计学分析（Kruskal-Wallis检验，p<0.05）。在5分钟、1小时和24小时时，所有测试糊剂的pH值范围为13.05至11.16。在48小时和7天时，所有测试糊剂的pH值范围为11.66至8.92。在14天和28天时，几乎所有糊剂的pH平均值均低于10。总之，所有测试的氢氧化钙糊剂的平均pH值随时间下降。用水性赋形剂（尤其是无菌水）制成的糊剂，其次是油性赋形剂（尤其是CMCP+甘油）制成的糊剂，在测试时间段内保持最高的pH平均值。
