Quantification of oral neutrophil counts in periodontal health and disease utilising a standardised oral rinse

Abstract

Background and Objectives: Polymorphonuclear neutrophils are the most abundant leukocytes in humans and are key host cells in defence against invading microorganisms. The oral neutrophil count may be an indicator of the periodontal health status, which correlates with the severity of periodontal disease. This study attempts to quantify orogranulocytes utilising an oral rinse and to assess the usefulness of this method in evaluating the oral inflammatory load much the same way the circulating neutrophils are used to screen for patients with infection in extra-oral sites. Methods: A total of 125 participants were divided into five groups with 25 subjects in each group. The groups consisted of healthy, gingivitis, mild periodontitis, moderate periodontitis, and severe periodontitis. Participants were asked to rinse with 10 mL of 0.9% saline for 30 s and to expectorate. Samples were centrifuged at 2000 RPM for 10 min. The supernatant removed was suspended in 5 mL of Hanks’s balanced salt solution. One millilitre of this suspension was mixed with 4 μL of acridine orange. A 10 μL aliquot of this suspension was then assessed on a haemocytometer, and the oral PMNs were counted using fluorescence microscopy. Results: The mean number of oral neutrophils (100,000 cells/mL) was the lowest in the healthy group and increased in ascending order across the different groups with the highest for severe periodontitis group. Conclusion: The oral neutrophil counts increased with the severity of periodontal inflammation. This is an easy, safe, reliable, and non-invasive method of quantification of oral neutrophils.