Measurement of nitrite and nitrate in saliva of children with different caries activity.

Abstract

Recently, there has been growing interest in the role of salivary nitrate and nitrite in caries protection. Nitrate is a natural compound found in fruits and vegetables and when secreted in saliva, is reduced to nitrite through bacterial respiration and subsequently reduced to nitric oxide in acidic condition. Nitric oxide takes part in oral non-specific immune system and prevents bacterial growth. The aim of present study was to determine the concentration of nitrite and nitrate in saliva of children with different caries activity. Ninety three children, 4 to 6 years old, enrolled in this case-control study and were divided into 3 groups; 31 caries free children, 31 with 5 <DFS ≤ 10 and 31 with DFS >10. Unstimulated saliva was collected and stored in 4°C. Measurement of nitrate and nitrite concentration was performed using Griess reaction. Data were analyzed by T-test, Chi-square, ANOVA and multiple comparisons using SPSS 18. p < 0.05 was considered significant. Mean value of DFS in the first, second and third were 0, 7.12 and 12.61 respectively. Mean value of nitrite and nitrate in the third group was significantly higher than two others (p < 0.05), but the difference between first and second group was not significant. Increase in DFS was associated by increase in salivary nitrite and nitrate concentration. High concentration of nitrate and nitrite is not enough for caries prevention.