牙菌斑液对牙釉质矿物的饱和程度与龋活动性的关系

为了解菌斑液对牙齿矿物饱和度随糖漱口的变化，以及与龋活动性的关系，作者选择２２例年龄相同的大学生，按龋齿情况，将其分为３组。第１组无龋（无龋组），第２组ＤＭＦＳ大于１０但无活动性龋（普通龋组），第３组ＤＭＦＳ大于１０且有活动性龋（活动性龋组），测定各受试者在静止时、用蔗糖液漱口后３ｍｉｎ和７ｍｉｎ时的菌斑液中有机酸、ｐＨ值、钙离子活度（有效离子浓度）和无机成分的含量，并计算对于釉质矿物的饱和度。结果表明，糖漱口之后菌斑液乳酸浓度升高、ｐＨ值降低、总钙和离子钙浓度增加。活动性龋组的菌斑液在糖漱口后ｐＨ值和饱和度降低的幅度明显大于无龋组和普通龋组。结论：牙菌斑液对牙齿矿物的饱和度是指示个体接受致龋食物后牙齿脱矿倾向的敏感指标。

Association of the degree of saturation with respect to enamel in plaque fluid with caries activity

The aim of this study was to investigate changes of the degree of saturation with respect to enamel in plaque fluid by sucrose rinse, and their association with caries activity. Three groups of subjects were selected by their caries status: caries free, caries positive and caries active. Plaque samples were collected before, 3 and 7 minutes after a one-minute 5% sucrose rinse. Plaque fluids were isolated and analyzed for organic acids (capillary electrophoresis), inorganic ions (ion exchange chromatography), calcium activity and pH (selective electrodes). The degrees of saturation (DS) were calculated based on the total composition or calcium activity. The results showed that there were significantly more pH drops, and particularly more DS drops within caries active group after a sucrose rinse, compared with caries free and positive groups. This suggests that the degree of saturation is a much sensitive index to describe the cariogenetic status of individuals.