Salivary calcium and total protein in relation to dental caries

Abstract

To evaluate the relationship between salivary components (calcium: Ca, total protein: T-Pro) and dental caries, we collected nonstimulated and expectorated saliva from 131 primary school children aged 11 years old. All salivary samples were taken in the morning (11:00~11:30 A.M.) on Feb. 17, 1994, while the subjects were at rest. The salivary Ca concentration (mg/dl), total salivary protein concentration (mg/ml) and salivary flow rate (ml/min) were measured based on the salivary sample taken for each person for 30 minutes at must. For each subject the Ca secretion rate (μg/min), T-Pro secretion rate (μg/min) anti Ca/T-Pro ratio were determined. The numbers of permanent teeth erupted, and decayed, missing and filled (DMF) teeth for each subject were obtained from dental records. For the entire group we observed that the numbers of DMF teeth were highly correlated with the numbers of permanent teeth erupted, hence for further analysis we restricted the subjects to 18 boys and 29 girls who were classified as dental age IIIC~IVA (according to Hellman's classification). Multiple linear regression analysis was employed using the number of DMF teeth as a dependent variable. When we included the variables for the Ca/T-Pro ratio, numbers of erupted permanent teeth, sex and salivary flow rate into the model as independent variables, there was a statistically significant association (P<0.05) between the Ca/T- Pro ratio and the numbers of DMF teeth. However, in other models there was no significant association between the numbers of DMF teeth with Ca concentration, Ca flow rate, total protein concentration, or total protein flow rate. Our results suggest that a high concentration of salivary Ca with a low concentration of total salivary protein may have a protective effect against dental caries.