Sharpened radiograph – surfaces – 12D and 13M show visual evidence of decay in outer part of enamel, but it is not clear if decay enters the dentin and if surfaces need to be restored.
[Source: Bradley A. Dykstra, DDS, Hudsonville, MI]

LOGICON Software shows decay has entered the dentin for surface 13M.

LOGICON Software shows decay has entered the dentin of contact surface 12D. 

Picture taken during restoration shows decay has penetrated the enamel (white material due to decalcification) and entered the dentin (brown spots) of both surfaces.
[Source: Bradley A. Dykstra, DDS, Hudsonville, MI]