The assessment of gingivitis using remote photoplethysmography

Abstract

Gum disease caused by bacterial infection, systemic conditions or neurogenic inflammation remains a prevalent and important concern of public health in both, developing and developed countries, potentially causing tooth loss if left untreated. Therefore, a simple, cost-effective, and contactless diagnostic tool is needed in dentistry. The present study aims to develop and investigate the feasibility of a motion artefact-free, miniature imaging photoplethysmography system which is dedicated for assessment of gingivitis in the dental office. The device comprised of a sub-miniature monochromatic camera equipped with miniature lens, 4-LED ring illuminator, cross polarizers and bandpass optical filter (CW=540nm, FWHM=25nm). The present pilot study comprised six subjects. The transitory neurogenic gingival inflammation has been induced by topical application of capsaicin containing chilli extract. The photoplethysmography signal was acquired from the same site before and after inflammation, and perfusion maps were computed. During the procedure, the developed imaging system demonstrated motion artefact-free data recordings and high signal to noise ratio. As expected, topical application of chilli extract produced noticeable transitory neurogenic inflammation, detected in perfusion maps. The present findings confirm the potential of imaging photoplethysmography for gingival tissue inflammation assessment, and in the future could be utilized in the dental office.