Violet and blue light-induced green fluorescence emissions from dental calculus: a new approach to dental diagnosis

Introduction Deposits of dental calculus when present either above the gingival margin or within periodontal pockets retain pathogenic microorganisms and their products, and have been linked to gingivitis and periodontitis.1,2 To ensure that clinicians are able to reliably detect calculus deposits, a range of special devices have been developed to augment traditional examination methods which rely on visual inspection for supragingival calculus, and tactile examination with a periodontal probe for subgingival calculus. Such methods include fluorescence in the near infrared region elicited by incident visible red light.3-6 Their application includes both assessment of deposits present at baseline before debridement, and checking root surfaces for remaining deposits at the end of a debridement visit.7-10 The use of near infrared fluorescence emissions (such as in the DiagnoDENT) requires phototransistors and other electronic sensors to be used, 11,12 since these wavelengths fall outside the visible spectrum. An enhanced clinical method for calculus detection using visible light would, in contrast, rely on what fluorescence emissions the clinician could see themselves. Subgingival calculus present on root surfaces associated with deep periodontal pockets can be seen with direct vision is when a surgical flap is raised.13 Another less invasive situation is when an intra-oral endoscopic camera is used for direct high magnification inspection of the subgingival environment. Such endoscopes (such as the Perioscope*) are shaped like periodontal probes or dental explorers, and contain solid glass rods or fiber-optic bundles within them, to both illuminate the object and then C L I N I C A L