Nitric Oxide Concentrations in Saliva in Relation to Caries; Experience in 6-12 Years Old Children

Abstract Introduction: Recently, there is a growing interest in the role of nitrate and nitrites in protecting against oral and gastrointestinal diseases. In human, ingested nitrate absorbs into the blood and concentrates in the salivary glands rapidly changes to nitrite. Nitrite may then be acidified through encounter with the plaque micro flora. The acidification of nitrite produces a mixture of nitrogen oxides as well as nitrous acid. Nitrous acid will spontaneously decompose to produce nitric oxide (NO). NO participates in the nonspecific defense mechanisms of the oral cavity to prevent bacteria from overgrowing. The aim of the study was to determine the correlation of nitric oxide with dental caries in children in mixed dentition period. Methods and Materials: The 3 ten-member groups of children aged 6 to 12 years with dfs < 1, 5 < dfs < 10 & dfs > 10 were selected. A 2 ml sample of saliva of each child were taken and transferred to laboratory, where by using the chromatograph unit, NO concentration was measured. Data were evaluated by ANOVA and t-tests. Results: Based on the laboratory findings, NO concentration in dfs < 1 group showed significant difference with other groups; but there was no significant difference of the NO concentration in groups with 5 < dfs < 10 and dfs > 10. Conclusion: The NO levels were higher in high dfs groups. NO production might be a host defense mechanism when dental caries increases. Key words: nitric oxide, saliva, caries