Introducing cut-points for salivary nitric oxide to distinguish periodontitis from the normal periodontium

We aimed to assess the diagnostic role of salivary nitric oxide (NO) to measure the periodontal health.

In this case-control study, we included patients with mild to moderate chronic generalized periodontitis (cases) and compared them with the healthy individuals (controls). Bleeding index, plaque index, gingival index, clinical attachment loss and probing pocket depth were recorded. In addition, un-stimulated saliva was collected and nitric oxide content was quantified by spectrophotometer using Griess reaction.

Twenty-seven and 17 individuals were enrolled as the case and control groups, respectively. All clinical indices were worse in the control group as compared to the cases (P<0.05). Salivary nitric oxide in patients with periodontitis was 169 (±86) mg which was significantly higher than the individuals with healthy periodontium (63 [±17] mg, P<0.001). Using a receive operation characteristic (ROC) curve, cut-points of 45 and 110 were obtained with the respective negative predictive value and positive predictive value of 1 and 1.

A higher level of salivary nitric oxide was observed in patients with periodontitis in comparison to the healthy individuals. This may indicate that progression to the periodontitis is derived by NO-pathways. Based on our findings, a chair side detection of salivary nitric oxide may be a valuable screening tool, especially when subclinical periodontitis is suspected.