Bond Strength of a Low-shrinkage Composite-resin Using Different Bonding Strategies

Objectives: This invitro study evaluated the micro-shear bond strength of a low-shrinkage composite to dentin using different bonding strategies.

Methods: Seventy extracted premolars were randomly assigned to seven groups (n=10). In groups 1-5 which Silorane composite resin were placed on prepared dentin following application of the adhesives, the bonding strategies were as followes:  Group 1: OptiBond Solo Plus (Opt; kerr), Group 2: SE Bond (SE; kurary), Group 3: silorane System Adhesive(LS primer & bond) (SSA; 3M ESPE), Group 4: OptiBond Solo Plus + LS bond of SSA (Opt LS), Group 5: SE Bond + LS bond of SSA (SE LS). In groups 6&7 as a control, Point 4 composite resin were used after applying  OptiBond Solo Plus (Opt Po) and  SE Bond (SE Po), respectively. After thermal cycling (1000 cycles at 5 and 55° C ), micro-shear bond test was carried out to measure the bond strengths. The results were analyzed using two-way and one-way ANOVA  and Tukey's post-hoc analysis (α = 0.05).

Results: There were no significant differences between two types of composites (P = 0.187), between bonding group (P = 0.06) and between composite and bonding (P = 0.894).  there were significant difference among groups of silorane composites (P = 0.045) and Tukey test showed there were significant difference  between Group 4 and 5. (P = 0.03)

Conclusions: The application of etch & rinse and self-etch methacrylate based adhesives with and without using of a hydrophobic resin coating produces acceptable bond strengths with silorane composite resin.