Which factor most strongly contributes to sealant failure?

• A. Poor bonding between resin and tooth structure
• B. Moisture contamination during placement
• C. Insufficient curing of resin
• D. Sealant pigments

Answer: (A)

Sealant longevity hinges on how well the resin can bond to etched enamel. When enamel is properly etched, microscopic porosities open up and the resin flows in to form resin tags that mechanically lock the sealant onto the tooth. This micromechanical bond is what holds the sealant in place during chewing and thermal cycling. If that bond is poor, the sealant will not adhere firmly, leading to debonding and failure, even if the material itself cures well.

Moisture during placement disrupts this bonding process by introducing a water layer and saliva that hinder resin penetration and tag formation, making failure more likely. Insufficient curing can weaken the resin, reducing its durability, but without a solid initial bond, failure is still driven by poor adhesion. Pigments don't affect the bonding mechanism and thus don’t contribute to retention.