Bond strength of six dentinal adhesives.

This study compared the shear bond strengths on dentine of five dentine adhesives against Scotchbond 2 as a control. Dentine specimens from 225 extracted human permanent molar teeth were used in a matched-pair design, such that 45 tooth sides were treated along with the matching control for each of the five test materials. Shear bond strength testing was conducted 24 h after the completion of each specimen. Results showed that mean force (MPa) for the materials were: XR Bond, 17.1 +/- 5.1; Scotchbond Multi-Purpose, 15.9 +/- 6.5; Syntac, 13.5 +/- 8.6; All-Bond 2, 6.2 +/- 4.1; Scotchbond 2 (control composite score), 4.9 +/- 3.0; Denthesive, 3.4 +/- 1.7. Matched pair t-test comparisons with Scotchbond 2 control were: XR Bond, P = 0.0005; Scotchbond Multi-Purpose, P = 0.0005; Syntac, P = 0.0005; All-Bond 2, P = 0.0368; Denthesive, P = 0.005. Analysis of variance determined a statistically significant difference (P = 0.05) between the means of the bond strengths, which fell into four groups: Group A, XR Bond and Scotchbond Multi-Purpose; Group B, Syntac; Group C, All-Bond 2 and Scotchbond 2; Group D, Scotchbond 2 and Denthesive. In Group C, there was no significant difference between Scotchbond 2 and All-Bond 2. In Group D there was no significant difference between Scotchbond 2 and Denthesive, however, there was significant difference between All-Bond 2 and Denthesive. It was concluded that XR Bond and Scotchbond Multi-Purpose had significantly better shear bond strength than the other dentine adhesives.