氢氧化钙对根管牙本质pH的影响

Effect of Calcium Hydroxide on Root Dentine pH.

目的 :旨在确定氢氧化钙置于髓腔内或根管内对根管牙本质不同位置pH的影响。方法 :取新鲜拔除的人单根管牙 ,常规根管预备 ,在牙根冠 1/ 3、中 1/ 3、尖 1/ 3钻三个小孔 ,根管内或髓腔内封入氢氧化钙糊剂 ,分别在 8h、1、2、3、7、14、2 1天测定小孔内牙本质pH。结果 :所有根管牙本质pH均显著升高 ,冠 1/ 3、中 1/ 3、尖 1/ 3pH随时间呈现相同的变化趋势 ,但无显著性差异 ;根管内和髓腔内封入氢氧化钙 ,根管牙本质PH无显著性差异。结论 :氢氧化钙封入髓腔内其羟基亦能有效扩散至根管牙本质中发生作用 ,对单根管而言不失为一种简便的根管消毒方法。

Objective:To determine root dentine PH after applicatio n of calcium hydroxide into root canal or pulp chamber.Methods:Forty-five freshly extracted single-root human teeth were used and root canal were preparation using conventional technique.Three cavities were drilled throu gh the dentine to within 1mm of the canal wall at the cervical, middle and apica l thirds.All samples were randomly divided into three groups.group 1: calcium hy droxide paste was placed in the root canal; group 2: calcium hydroxide paste was placed in the pulp chamber; group3: control group, wet canal without medication . The PH was measured in the dentinal cavities at 8h, 1, 2, 3, 7, 14 and 21 days .Results:Root dentine PH n group 1 and group 2 were signif icantly higher than control group PH; there was no significant difference among the cervical, middle and apical PH;there was no significant difference between g roup 1 PH and group 2 PH.Conclusions:Calcium hydroxide pas te placed in the pulp chamber increased root dentinal PH by the diffusing of hyd roxyl ions.