Mustafa Mohammed, Alaajam Wafa Hassan, Azeim Ahmed Abdul, Alfayi Najla Aedh, Alqobty Rahaif Misfer, Alghannam Shahad
Department of Conservative Dental Sciences, Division of Endodontics, College of Dentistry, Prince Sattam bin Abdulaziz University, AlKharj, Saudi Arabia.
Department of Conservative Dental Sciences, Division of Endodontics, College of Dentistry, King Khalid University, Abha, Saudi Arabia.
Eur J Dent. 2018 Jul-Sep;12(3):386-392. doi: 10.4103/ejd.ejd_77_18.
Studies about the dispersion of hydroxyl ions through dentin of endodontically retreated teeth are scarce. The present study aims at examining the diffusion of calcium hydroxide by recording the pH changes of retreated root canal using two types of calcium hydroxide preparations.
A total of 45 recently extracted single-rooted mandibular first premolars were collected and cleaned from calculus and remains of periodontal tissue. The teeth so collected were stored in thymol 10% solution till use. During collection, teeth with cracks, open apices, and restorations were excluded. Root canal preparations were performed using Protaper rotary system files, till #F3 file. All canals were obturated using cold lateral condensation and zinc oxide-based sealer. After 7 days, all gutta-percha were removed and the canals were irrigated with normal saline. The teeth were then randomly distributed into three groups. Canals in Group I were kept empty without any dressing to serve as a negative control group, Canals in Group II were filled with a freshly prepared mixture of calcium hydroxide powder with normal saline solution, and Group III was filled with Metapex. Periodically, the calcium hydroxide material was removed and the pH was measured using pH meter at 7, 10, 14, and 30 days.
The pH values of Group II and III ranged between 9.2 and 11.2. This was found to be highly significant against the negative control group. After 7 and 10 days, freshly mixed Ca(OH) showed the higher pH than the creamy Metapex, and statistically the difference was highly significant after 10 days (<0.001). After 14 days, Metapex group pH was higher than freshly mixed Ca(OH), but it was not statistically significant as they reached nearly the same pH after 30 days (>0.05).
All Ca(OH) preparations had high pH around the roots after 7 and 10 days. Metapex continued to have higher pH after 14 days.
关于羟基离子在根管再治疗牙齿牙本质中的扩散研究较少。本研究旨在通过使用两种氢氧化钙制剂记录再治疗根管的pH变化来检测氢氧化钙的扩散情况。
共收集45颗近期拔除的单根下颌第一前磨牙，清除牙石和牙周组织残余。将收集到的牙齿保存在10%麝香草酚溶液中备用。收集过程中，排除有裂纹、根尖开放和有修复体的牙齿。使用Protaper旋转系统锉进行根管预备，直至F3锉。所有根管均采用冷侧方加压充填和氧化锌类封闭剂。7天后，去除所有牙胶，并用生理盐水冲洗根管。然后将牙齿随机分为三组。第一组根管保持空管，不进行任何封药，作为阴性对照组；第二组根管内充填新配制的氢氧化钙粉末与生理盐水的混合物；第三组根管内充填Metapex糊剂。定期在第7、10、14和30天取出氢氧化钙材料，使用pH计测量pH值。
第二组和第三组的pH值在9.2至11.2之间。与阴性对照组相比，差异具有高度统计学意义。在第7天和第10天后，新混合的Ca(OH)显示出比乳膏状Metapex更高的pH值，在第10天后统计学差异具有高度显著性（<0.001）。在第14天后，Metapex组的pH值高于新混合的Ca(OH)，但差异无统计学意义，因为在第30天时它们的pH值几乎相同（>0.05）。
所有氢氧化钙制剂在第7天和第10天后牙根周围均具有较高的pH值。在第14天后，Metapex糊剂的pH值持续较高
