[Studies of the bond of two different types of composites to etched enamel]

The strength of the bond between a microfilled or, respectively, a hybride composite and acid-etched enamel was examined in a shear test and by SEM in human teeth after different modes of preparation. The results showed that the best bond strengths were obtained with microfilled resin without use of a bonding agent. The retention of the hybride composite was better in combination with a bonding agent. Mechanical reduction of the enamel increased the bond strengths of all tested materials.