Salivary nitric oxide, Simplified Oral Hygiene Index, and salivary flow rate in smokers and non-smokers: a cross-sectional study.

Salivary nitric oxide plays an important role as an antibacterial agent in the oral cavity. Here, we analyze salivary nitric oxide, Simplified Oral Hygiene Index (OHI-S) scores and the salivary flow rate in smokers and non-smokers which has not been done previously. A cross sectional study included 25 smokers and 25 non-smokers. Their OHI-S results were categorized as "good," "medium," or "bad." Unstimulated saliva samples were collected, and their nitric oxide concentration was measured using the Griess method. The salivary flow rate in smokers was lower, at 0.30 ml/minute, compared to non-smokers who had a salivary flow rate of 0.33 ml/minute. This was statistically insignificant. There was a significant difference in the concentrations of nitric oxide between smokers and non-smokers (p < 0.05). Smokers had higher concentrations than non-smokers (185.4 µM Vs 114.60 µM). In addition, there was a moderate positive correlation (r = 0.305) between the concentration of salivary nitric oxide level and the OHI-S results. It was concluded that salivary nitric oxide concentration was higher in smokers, and the oral hygiene condition of smokers was poor.