Colorado stains (TSIF — Tooth Surface Index of Fluorosis) are used for which purpose?

Correct answer: C. Evaluation of fluorosis severity on tooth surfaces

• A. Enamel defect classification by etiology uses developmental chronology and clinical description — not TSIF.
• B. Periodontal staging uses AAP classification (Stage I-IV).
• C. Correct. The Tooth Surface Index of Fluorosis (TSIF) and Colorado stain (Oehler's classification is separate) are systems used to assess and classify the severity and distribution of dental fluorosis on tooth surfaces. This is used in epidemiological studies of water fluoridation effects.
• D. Caries risk categories use systems like CAMBRA — not Colorado/TSIF.