Assessment of the clinical status of primary root carious lesions using an enzymic assay

The microflora of root carious lesions (n = 151) and sound root surfaces (n = 30) in 22 institutionalized, older patients was investigated using a standardized method of sampling. Material was removed using a sterile excavator and the numbers of bacteria in each sample were determined using conventional culturing techniques and by rapid (2 h) fluorogenic enzyme assay. Correlation between bacterial counts and enzyme assay result was 0.873 (p < 0.001). The numbers of bacteria and fluorogenic enzyme assay values were significantly (p < 0.001) greater from soft lesions than from leathery lesions while hard lesions and sound root surfaces had significantly (p < 0.001) lower values than the other lesion types and were not different from each other. A similar trend was apparent when these values were correlated with treatment needs. The fluorogenic enzyme assay may provide a rapid, objective measure of root caries severity which might be used in the monitoring and comparison of treatment protocols.