3. Pulpal caries: The carious lesion discussed prior to this point has been limited chiefly to coronal
caries, and process has involved basically the enamel and dentin of that portion of the tooth. Another form of
disease does exit which is known as root caries or root surface caries. At one time it was also referred to as
caries of cementum. It is generally recognized that the longer life span of persons today, with the retention of
teeth into the later decades of life has increased the no: of population exhibiting gingival recession with
clinical exposure of cemental surfaces and there by probably increasing the prevalence of root caries. Root
surface must be exposed to the oral environment before caries can develop here. In this section dental caries
classification is performed based on the edge detection: The caries affected tooth is selected, which is
subsequently used for caries classification