Fig. 5

Special cases. Top row: a White light image of gingival recession; the dentin root of the tooth has been exposed. b The reference device exaggerated the natural yellow color of the dentin to look like plaque; however, (c) the Plaquefinder showed no visible red fluorescence. Hygienist confirmation of these teeth as clinically plaque-free demonstrates higher specificity in the Plaquefinder. Middle and bottom row: Dental restoration under different imaging modes: d Reference device white light; e Reference device plaque mode; f Plaquefinder white light; g Plaquefinder 405 nm light. The natural green fluorescence of the tooth is contrasted greatly from the restoration in (g). Bacterial activity is visible at the margin as indicated by red fluorescence, a common precursory location for secondary caries