Bond strengths of two self-adhesive resin cements to dentin with different treatments

Abstract

The aim of this study was to evaluate the shear bond strength of two self-adhesive resin cements applied to dentin surfaces treated with different methods. Sixty human dentin specimens were sectioned to expose flat superficial dentin surfaces. The teeth were assigned to six groups and treated with various methods: no surface conditioning (groups A and B); phosphoric acid etching (groups C and D); etching with phosphoric acid and One-step resin-based adhesive (groups E and F). Two resin cements were subsequently applied to the dentin surfaces, RelyX Unicem for groups A, C and E and Biscem for groups B, D and F. Bonded specimens were immersed in water for 24 hours, then shear bond strength was determined. The bonded interface was examined by scanning electron microscopy. According to the results in this study, mean bond strengths and standard deviations of the 6 groups are, Group A 5.30 ± 1.59 MPa, Group B 5.26 ± 1.62 MPa, Group C 8.94 ± 3.69 MPa, Group D 7.39 ± 1.48 MPa, Group E 10.01 ± 2.06 MPa, and Group F 9.17 ± 0.86 MPa. The bond strengths for groups A and B were significantly lower than those for groups C and E and groups D and F, respectively. No statistically significant difference was found between groups A and B, groups C and E, or groups D and F. It can be concluded that phosphoric acid etching improved bond strength of the two self-adhesive resin cements to dentin.