Method: The fiber-reinforced composite everX Posterior (GC) was bonded in 4-mm bulk to bur-cut human dentin using the one-step self-etch adhesive and the three-step etch-and-rinse adhesive Optibond FL (Kerr). A conventional paste-like composite (G-ænial Posterior, GC), bonded using G-ænial Bond (GC) and applied/cured in bulk as well as in two 2-mm layers, served as control. After 1 week of water storage, the teeth were sectioned to 1x1 mm (non-trimmed) micro-specimens and tested in tensile to determine the micro-tensile bond strength (μTBS). The mean μTBSs were subjected to one-way ANOVA and a post hoc multi-comparisons test (Tukey–Kramer test) at a significance level of 0.05.
Result:
|
Mean±SD (MPa) |
ptf/n |
G-ænial Bond + everX Posterior, 4-mm bulk-cured |
35.3±11.3a |
0/37 |
Optibond FL + everX Posterior, 4-mm bulk-cured |
35.4±9.8a |
0/34 |
G-ænial Bond +G-ænial Posterior, 4-mm bulk-cured |
13.5±11.0b |
13/38 |
G-ænial Bond +G-ænial Posterior, 2x 2-mm layer-cured |
29.2±13.3a |
0/38 |
SD: standard deviation; ptf=pre-testing failure, included as 0 MPa in the calculation of the mean; n=number of specimens; means with the same superscript are not significantly different (Tukey HSD, p<0.05)
Conclusion: When applied in 4-mm bulk, the fiber-reinforced composite bonded, irrespective of the adhesive employed, equally effective to bur-cut dentin as the conventional paste-like composite that however needed to be applied/cured in two 2-mm layers.