The International Caries Detection and Assessment System (ICDAS) is a standardized visual method for diagnosing and classifying dental caries at various stages. It uses codes from 0 to 6 to describe the severity of tooth decay:

• 0 – Sound tooth surface

• 1 – First visual change in enamel

• 2 – Distinct visual change in enamel

• 3 – Localized enamel breakdown without visible dentin involvement

• 4 – Underlying dark shadow from dentin

• 5 – Distinct cavity with visible dentin

• 6 – Extensive distinct cavity with visible dentin

ICDAS enables dentists to accurately assess the extent of caries, choose appropriate treatment, and monitor disease progression, which is essential for effective prevention and tooth preservation.