Dental According to the Nathoo classification, the chromogen changes color after binding to the tooth is categorized under: A N1 type stain B N2 type stain C N3 type stain D N4 type stain 💡 Explanation According to the Nathoo classification, the chromogen changes color after binding to the tooth is categorized under: ✓ Correct Answer: B. N2 type stain