The effect of removal of the smear layer on microleakage of Class V restorations in vitro

The effect of removal of the dentinal smear layer on microleakage of Class V restorations in vitro was evaluated using 3 restorative techniques: a composite resin with its dentin bonding agent, a composite based with glass-ionomer lining cement, and a glass-ionomer restorative cement. The agent used to remove the smear layer was a commerical 10% polyacrylic acid. Removal of the smear layer did not have any affect on microleakage of each of 3 types of restorations considered separately. The results favor removal of the smear layer only when a glass-ionomer linear is used under the composite restoration. The microleakage of the glass-ionomer restorations was greater than either the composite or composite based with glass-ionomer liner.