If etched enamel becomes contaminated, the recommended action is to

• A. Polish and seal
• B. Continue without cleaning
• C. Apply primer only
• D. Re-etch, rinse, and dry again

Answer: (D)

Contamination after enamel etching disrupts the micromechanical bond because the resin cannot properly infiltrate the pores created by the acid. Saliva, blood, or moisture fills or blocks those etched porosities, preventing the formation of resin tags that anchor the adhesive to the enamel surface. The remedy is to re-etch the enamel, which reopens the porosities, then thoroughly rinse away the debris and contaminants and dry the surface to a clean, frosted appearance before applying the bonding agent. This restores the proper bonding surface.

Polishing and sealing would erase the etched surface and not restore porosity. Continuing without cleaning leaves the surface contaminated and weakens adhesion. Applying primer alone cannot re-create the etched porosities needed for a strong bond. Re-etching, rinsing, and drying reestablish the necessary surface for reliable bonding.