For the WHO caries assessment system, the examiner recorded a surface as decayed only if it presented with detectably softened floor, undermined enamel or a softened wall. According to this criterion, all the stages that precede cavitation as well as other conditions similar to the early stages of a carious lesion were considered sound.
For the ICDAS system, the D stands for detection of dental caries by (i) stage of the carious process; (ii) topography (pit and fissure or smooth surfaces); (iii) anatomy (crown vs roots); and (iv) restoration or sealant status. The A in the ICDAS stands for assessment of the carious process by the stage (non-cavitated or cavitated) and activity (active or arrested). This study does not include an assessment of the lesion activity or root caries.