Marginal leakage of composite resin restorations in combination with dentinal and enamel bonding agents

Marginal leakage is a cause of failure of composite resin restorations. The effect of two enamel and two dentin bonding agents on marginal leakage alongside composite resins was assessed and compared in enamel and dentinal cavities. Cavities, one in buccal enamel and the other in cervical dentin, were prepared in each of 350 extracted sound human premolar teeth and randomly assigned to combinations of bonding agents and composite resins. After insertion the restorations were polished and the restored teeth were stored in distilled water and thymol at 20 degrees C for 28 days. This was followed by thermal stressing (15 degrees C and 45 degrees C) for 24 hours with a dip cycle of 30 seconds, whereafter a marginal leakage test was performed. The results showed that in enamel cavities, the bonding agents Enamelbond, Heliobond, and Scotchbond significantly reduced marginal leakage compared with Dentin-Adhesit. In the dentinal cavities, Dentin-Adhesit and Scotchbond reduced marginal leakage compared with Enamelbond and Heliobond. No significant difference was noted in the sealing ability of Dentin-Adhesit and Scotchbond. In dentin the P10/Dentin-Adhesit, and Silar/Scotchbond combinations sealed significantly better than P10/Enamelbond.