SHEAR BOND STRENGTH AND DURABILITY OF 4-META BASED PORCELAIN REPAIR SYSTEMS

Abstract

Objective: To compare the resin-porcelain shear bond strengths and their durability using a modified 4-META based porcelain repair system and other current systems. Material and method: One hundred specimens were prepared from feldspathic porcelain. The specimens were bonded to resin with five porcelain repair systems (20 pieces each): Superbond C&B (SB), Bondfill SB (BF), Single bond universal (SU), Heliobonds (HB) and Vertise flow (VF). In each group, shear bond strength of 10 specimens were tested after 24-h water storage, and the other 10 specimens were tested after 5,000 thermocycles. All data were statistically analyzed by two-way ANOVA and T-test (p<0.05). All substrate surfaces were investigated their fracture modes by a stereomicroscope. Fracture surfaces were categorized as adhesive, cohesive or mixed failure. Results: The mean shear bond strength among 5 groups at 24-h water storage varied from 12.3 MPa to 28.8 MPa and they varied from 4.14 MPa to 25.1 MPa after thermocycling. There was no statistically significant different in bond strength before and after thermocycling in HB, SB and BF. The significant lower bond strength after thermocycling was statistically significant in SU and VF. The mean shear bond strength was influenced by the type of porcelain repair system and thermocycling. All group exhibited more mixed and adhesive failure, except HB group. Conclusions: A modified 4-META based porcelain repair system is an alternative choice for repairing porcelain.