Resin infiltration (ICON) is indicated for which lesion type?

• A. Non-cavitated proximal enamel lesions.
• B. Cavitated dentin caries.
• C. Root caries.
• D. Post-eruptive enamel defects.

Answer: (A)

Resin infiltration works by penetrating porous, non-cavitated enamel lesions with a low-viscosity resin to halt caries progression by blocking acid diffusion, all while preserving tooth structure. This approach fits best with non-cavitated proximal enamel lesions because the lesion is still confined to enamel and accessible for the resin to infiltrate from the contact area, effectively arresting the decay without removing tooth structure. Cavitated dentin caries have broken the surface and extend into dentin, where infiltration cannot reliably seal and stop progression, so restoration becomes the appropriate option. Root caries involve exposed cementum/dentin at the root surface, where bonding and resin penetration are less predictable, making infiltration unsuitable. Post-eruptive enamel defects are developmental issues, not active caries, so resin infiltration isn’t indicated for them.