Sealant Mechanism — NDEB AFK MCQ

Correct answer: D — Physical barrier preventing bacterial colonisation and nutrient access to the fissure

Pit and fissure sealants prevent caries primarily by creating a physical barrier — filling the deep, narrow, and morphologically complex pits and fissures with a resin or glass ionomer material. This prevents bacterial colonisation of these retention sites and eliminates the stagnation area where plaque accumulates. Even bacteria sealed beneath intact sealant become non-viable due to lack of nutrient supply. Sealant retention is the critical factor for effectiveness.

Reference: CDA – Position Statement on Dental Sealants; ADA – Evidence-Based Dental Sealant Guideline, 2023