Table 1.

Criteria used for visual and radiographic examination and actual lesion depth

Score	Visual examination	Radiographic examination	Lesion depth
0	No or slight change in enamel translucency after prolonged air (> 5 s)	No radiolucency visible	No enamel demineralisation or a narrow surface zone of opacity
1	Opacity or white and brown discoloration hardly visible on the wet surface, but distinctly visible after air drying	Radiolucency visible in the enamel	Enamel demineralisation limited to the outer 50% of the enamel layer
2	Opacity or white and brown discoloration distinctly visible without air drying	Radiolucency visible in the dentine but restricted to the outer third of the dentine	Demineralisation involving between 50% of the enamel and 1/3 of dentine
3	Localised enamel breakdown in opaque or discoloured enamel and/or grayish discolouration from the underlying dentine	Radiolucency extending to the middle third of dentine	Demineralisation involving the middle one-third of dentine
4	Cavitation in opaque or discoloured enamel exposing the dentine	Radiolucency in the pulpal third of dentine	Demineralisation involving the inner one-third of dentine