Table 1: The international caries detection and assessment system (ICDAS II) index

Score	Meaning
0	South tooth surface. There should be no evidence of caries (either no or a questionable change in enamel translucency after prolonged air drying (approximately 5 seconds). Surfaces with developmental defects, such as enamel hypoplasias, fluorosis, tooth wear (attrition, abrasion and erosion) and extrinsic or intrinsic stains will be recorded as sound.
1	First visual change in enamel. Then seen wet, there is no evidence of any change in color that can be attributed to carious activity, but, after prolonged air drying, a carious opacity is visible that is not consistent with the clinical appearance of sound enamel.
2	Distinct visual change in enamel when viewed wet. There is a carious opacity or discoloration that is not consistent with the clinical appearance of sound enamel (Note: The lesion is still visible when dry). The lesion is located in close proximity (in touch with or within 1 mm) to the gingival margin.
3	Localized enamel breakdown due to caries with no visible dentin. After being dried for 5 seconds, there is carious loss of surface integrity without visible dentin.
4	Underlying dark shadow from dentin with or without localized enamel breakdown. This lesion appears as a shadow of discolored dentin visible through the enamel surface beyond the white or brown spot lesion, which may or may not show signs of localized breakdown. This appearance is often seen more easily when the tooth is wet and is a darkening and intrinsic shadow that might be gray, blue or brown.
5	Distinct cavity with visible dentin. Cavitation in opaque or discolored enamel exposing the dentin beneath.
6	Extensive distinct cavity with visible dentin. Obvious loss of tooth structure, the cavity is both deep and wide, and dentin is clearly visible on the walls and at the base. An extensive cavity involves at least half of the tooth surface or possibly reaches the pulp.