菌斑pH值、游离钙和总蛋白水平与根龋易感性的关系

The dynamics of pH、free calcium and total proteins in root plaque fluid and their relationships to the cariogenic potential

目的 分析菌斑液成分的动态变化与根龋易感性的关系。方法 比较无根龋组和有根龋组根面牙菌斑液在糖溶液漱口前后 ,所测定pH值、游离钙 (微电极法 )和总蛋白水平 (分光光度法 )的差异。结果 静止状态下 ,无根龋组和有根龋组的pH值 (无根龋组 6 2 4± 0 74,有根龋组 5 96±0 70 )和游离钙 [无根龋组 (0 6 0± 0 46 )mmol/L ,有根龋组 (0 89± 0 5 4)mmol/L]两项指标差异无统计学意义 ;糖漱口后 ,有根龋组的pH(5 14± 0 19)和游离钙 [(1 73± 0 74)mmol/L]水平均低于无根龋组[pH 5 2 8± 0 16 ,游离钙 (2 73± 1 2 5 )mmol/L],差异有统计学意义。总蛋白水平与游离钙含量之间没有相关性。同一个体牙根面与冠面之间菌斑液的三项指标均有显著的相关关系。结论 有根龋组的菌斑液有较强的致龋倾向 ,在细菌酵解糖产酸方面 ,牙根面 (牙骨质 )菌斑与牙冠面 (牙釉质 )

Objective To enhance knowledge of root caries by analysis of the dynamics of dental plaque fluids on root surface and their relationships with the caries history. Methods The pH, free calcium and total proteins of dental plaque fluids on sound root surfaces were analyzed before and after the sucrose challenge. Subjects were either root caries free (RCF) or caries positive (RCP).Results After a sucrose challenge, the pH of plaque fluids dropped significantly and the concentration of free calcium increased significantly. There were no statistical differences in pH (RCF group 6.24±0.74, RCP group 5.96±0.70) and free calcium [RCF group (0 60±0 46) mmol/L, RCP group (0 89±0 54) mmol/L] between RCF and RCP group before sucrose challenge. Following sucrose exposure, pH (5.14±0.19) and free calcium [(1 73±0 74) mmol/L] in RCP group were significantly lower than RCP group [(pH 5.28±0 16), free calcium (2.73±1.25) mmol/L] No interrelationship has been found between the amount of total proteins and free calcium . Components (contents, change trend) in root plaque were strongly related to that in coronal plaque. Conclusions The process of root caries may be consistent to coronal caries regarding to the acid production of bacteria after a sucrose challenge. Plaque compositions show a stronger cariogenic potential in RCP group.