Bonding ability of light cured composite resin to enamel and dentin promoted by various bonding systems--microleakage and bond strength studies.

The purpose of this study was to estimate bond strength between light cured composite resin and enamel or dentin, and marginal sealing ability of composite resin promoted by five commercial bonding systems. At first, tensile bond strength between light cured composite resin and enamel or dentin promoted by these bonding systems were measured. Next, class V cavities were prepared at cementoenamel junction of extracted human molars and filled with light cured composite resin, using the same bonding systems. Microleakage around the restoration was estimated by dye penetration test. All bonding systems presented high bond strength and good marginal sealing between composite resin and enamel. The bonding systems which presented high bond strength between composite resin and enamel or dentin inhibited microleakage around restoration effectively. However, no bonding system could inhibit microleakage completely at the cementum/dentin-composite resin interface.