in‑vitro comparison of the effect of different bonding strategies on the micro‑shear bond strength of a silorane‑based composite resin to dentin

background: the current study evaluated the micro‑shear bond strengths of a new low‑shrinkage composite resin to dentin. materials and methods: in this in‑vitro study, 70 extracted premolars were assigned to one of seven groups ( n = 10): group 1: optibond solo plus (opt; kerr); group 2: se bond (se; kuraray); group 3: silorane system adhesive (ssa; 3m espe); group 4: optibond solo plus + ls bond (opt ls); group 5: se bond + ls bond (se ls); group 6: optibond solo plus (opt po); and group 7: se bond (se po). occlusal dentin was exposed and restored with filtek ls (3m espe) in groups 1 to 5 and point 4 (kerr) in groups 6 and 7. after thermocycling (1000 cycles at 5/55°c), micro‑shear bond test was carried out to measure the bond strengths. the results were submitted to analysis of variance and post hoc tukeytests ( p < 0.05). results: two‑way anova showed no significant differences between the two types of composite resin ( p = 0.187), between bonding agents ( p = 0.06) and between composite resin and bonding agents ( p = 0.894). because p value of bonding agents was near the significance level, one‑way anova was used separately between the two composite groups. this analysis showed significant differences between silorane composite resin groups ( p = 0.045) and tukey test showed a significant difference between groups 4 and 5 ( p = 0.03). conclusion: the application of total‑etch and self‑etch methacrylate‑based adhesives with and without use of a hydrophobic resin coating resulted in acceptable bond strengths. key words: low, contraction, composite resins, bonding agents, micro, shear, bond, strength