Bond strength of a resin-based composite to leucite-reinforced ceramic anddentin

Purpose: To compare the in vitro tensile bond strengths of resin-based comp osite bonded to dentin and to a leucite-reinforced ceramic in an as-receive d condition (pre-silanated) or re-etched, re-silanated condition. Materials and Methods: Caries-free human molars were ground to expose occlusal, supe rficial dentin. Dentin surfaces were etched with 37% phosphoric acid and ri nsed, leaving a moist dentin surface. Leucite-reinforced ceramic inserts (S ONICsys) also were tested as received (pre-etched, pre-silanated) or retrea ted with hydrofluoric acid and silane. Bonding agent (Syntac Single-Compone nt) was applied in two layers and light cured. An all-purpose resin-based c omposite (Tetric Ceram) was used to prepare tensile bond strength specimens for the dentin and two ceramic groups. Fourteen specimens were prepared fo r each group. After 24 hours in distilled water, tensile bond strength (MPa ) was measured using a testing machine. Analysis of variance was used to ev aluate data. Results: Bond strengths obtained were 10.2 MPa for composite b onded to dentin, 10.5 MPa for composite bonded to as-received ceramic inser ts, and 9.6 MPa for composite bonded to retreated ceramic inserts, with no statistical difference between the three groups. Re-treatment of leucite-re inforced inserts did not increase or decrease bond strength to resin-based composite. Also, the bond strength of resin-based composite to dentin was s imilar to that of the ceramic to composite.