How are moderate caries defined by G.V. Black?

Moderate caries, as defined by G.V. Black, represents a specific stage in the progression of dental caries. The definition indicates that a moderate lesion is one that extends more than halfway through the enamel. This stage is crucial in understanding the severity and potential treatment of carious lesions.

In dental terminology, active caries are generally assessed based on their depth and the amount of tooth structure they compromise. When a carious lesion reaches beyond the halfway point of the enamel, it signifies that the lesion has transitioned from incipient (initial stage) to moderate, demonstrating a significant degree of tissue demineralization and potential progression toward the dentin if not addressed promptly. Identifying and categorizing caries is essential for determining the correct intervention strategy, whether it be monitoring, remineralization, or restorative treatment.

The other options represent either earlier stages of caries or more advanced forms, which do not correctly capture the essence of what defines moderate caries according to G.V. Black's classification.