Saliva nitric oxide levels in relation to caries experience and oral hygiene

Abstract

The aim of the present study was to determine the relationship between nitric oxide (NO) concentration/rate in the unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) with the decay-missing-filled teeth (DMFT) and simplified oral hygiene (OHI-s) scores. Forty adults were included in the study. Half of the participants ( n = 20) had high DMFT-OHI-s compared to the other half. UWS and SWS flow rates, initial and final pHs were also measured. NO concentrations in the UWS and SWS of high and low DMFT-OHI-s groups were determined using modified Griess reaction and NO rates were calculated. The two groups revealed no significant differences in their salivary flow rates and their initial pH. NO concentrations/rates in the UWS and SWS of high and low DMFT-OHI-s groups were not statistically different ( p > 0.05). There was no significant correlation between NO concentration or NO rate and other tested variables (DMFT-OHI-s, initial pH and final pH). However, a significant correlation was found between UWS NO rate and UWS flow rate ( r = 0.921, p = 0.0001) and SWS NO rate and between SWS flow rate ( r = 0.921, p = 0.0001). It could be concluded that neither NO concentration nor NO rate correlates with the dental status. As the exposure to any salivary component (including NO) depends not only on its concentration but also on the rate of production of such concentration, it would be of value when determining individuals’ salivary components to consider their rate values rather than their absolute concentrations.