镧、钙、氟对菌斑pH影响的实验研究

A Comparative Study About the Influence of Lanthanum,Calcium, Fluoride on Plaque pH

目的 :对比镧、钙、氟对菌斑pH变化过程的影响 ,从菌斑代谢角度探讨镧的抗龋作用。方法 :采用接触法连续测定含La3+、Ca2 +、F-的蔗糖溶液含漱后的菌斑pH值 ,对pH值下降至最低所用的时间、最低pH、pH下降的幅度(ΔpH)以及pH变化曲线中pH6 5以下的曲线下面积 (AUC6 .5)进行双因素方差分析。结果 :8名受试对象之间各参数均无明显差别 ;各处理方法相比蔗糖溶液对照组导致菌斑pH下降的幅度最大 ,其次是含钙蔗糖溶液处理组 ,再次是含氟蔗糖溶液处理组及含镧蔗糖溶液处理组 ,后两者之间差异无显著性 ;各处理方法导致菌斑pH下降所需时间差异无明显性。结论 :钙、镧、氟均可减小摄入蔗糖后菌斑pH的下降幅度 ,钙的作用最弱 ,镧和氟的作用相似 ,表明镧可干扰菌斑的产酸过程。

Objective: The study is designed to compare the effects of Lanthanum (La), Calcium (Ca), Fluoride (F) on pH changes of plaque, and to discuss the anti-cariogenic mechanisms of Lanthanum in terms of metabolism. Methods: Plaque pH values after sucrose solution (containing La+{3+}, Ca+{2+}, F+-) rinse were measured contiguously using micro-touch method, and then the minimum pH, time of minimum pH, ranges of plaque pH (ΔpH), and areas of the response curves below (AUC6.5) were analyzed using two-way analysis of variance (ANOVA). Results: No statistical difference was found in the above monitored parameters of 8 subjects. For the decreasing degree of plaque pH, the pH value in the control group fell down the most obvious, and the second was that in the Ca group. The pH value decreased the least in the F and La group, and there was no significant difference between the F and La group. The time of minimum pH was the same in each group. Conclusion: Ca, La, F can decrease the range of plaque pH drop after sucrose solution rinse. The degree of Ca was the weakest, and F and La were same. All the above evidences prove that La may inhibit the acidogenicity of plaque.