A COMPARISON OF PRIMARY ROOT CARIES LESIONS CLASSIFIED ACCORDING TO COLOR

Three hundred and ninety-five primary root caries lesions in 117 patie nts were included in this study. Each lesion was clinically characteri sed (colour dimensions, distance from gingival margin and texture) and a sample of infected or altered dentine was taken using a standardise d sampling procedure. The relationships between the colour and the mic roflora, texture, physical dimensions and distance from the gingival m argin of the lesions were investigated. Lesions in each colour group ( light brown, yellow, dark brown and black) were identified in each tex ture category (soft, leathery and hard), except for black lesions whic h were recorded as only soft or leathery. Black soft and black leather y lesions had a significantly greater area and harboured more lactobac illi than all other types of lesions while black leathery lesions also harboured significantly more yeasts. There were no significant differ ences in the number of bacteria or mutans streptococci isolated from s oft or leathery lesions irrespective of lesion colour. Overall, these data indicate that the colour of primary root caries lesions is not a reliable indicator of primary root caries activity. Assessment of the clinical severity of primary root caries lesions requires consideratio n of lesion texture and the distance of the lesion from the gingival m argin rather than the colour of the lesion.