Introduction Nitric oxide (NO) plays an important role in almost every biological system. The increase in NO in periodontal tissues has been reported in inflammatory periodontal disease, which suggests the production and participation of NO in the disease process. However, the association between salivary NO levels and periodontitis was rarely reported. The aim of this study was to assess the periodontal health according to the salivary NO levels in Korean elderly.

Methods 203 subjects aged 48–84 years old were cross-sectionally surveyed. All participants underwent oral examination. Age, gender, education level, regular exercise, smoking were evaluated through interview. Periodontal health status was evaluated by clinical attachment loss over 6 mm (CAL6 mm) for 6 points of 12 index teeth (total 72 sites). The number of CAL6 mm sites was counted. Unstimulated saliva was collected for 10 min. Salivary NO was determined by the Griess reagent. ANCOVA and Multiple linear regression analyses were applied.

Results After correcting for differences in for age, gender, education, regular exercise, smoking, salivary flow rate, and number of natural teeth, high NO level group showed the highest number of CAL6 mm sites (15.2 vs 7.0 and 10.8, p=0.031). Salivary NO levels had a dose-effect relationship with the number of CAL6 mm sites (β=0.026, p=0.011).

Conclusion NO levels are elevated in individuals with periodontitis. These results reveal that periodontal disease and its severity are related to salivary NO concentration, indicating that NO may serve as a potential biological marker for detection and monitoring of periodontitis.