Effects of chemical and physico-chemical surface conditioning methods on the adhesion of resin composite to different mineral trioxide aggregate based cements

This study investigated the adhesion of resin composite to mineral trioxide aggregate based cements after different chemical and physico-chemical surface conditioning methods. Mineral trioxide aggregate based cements (Biodentine, ProRoot MTA, Imicryl MTA) were embedded in Teflon disks (N = 180). After storing at 37 degrees C at 100% humidity for 72 h, substrate surfaces were polished using silicon carbide papers. Specimens were allocated to 3 groups to be conditioned with one of the following (n = 15 per group): a) Adhesive resin (Clearfil SE Bond, CSE), b) Adhesive resin (Adper Single Bond 2, SB2), c) air-abrasion with 30 mu m alumina coated with silica + silane + adhesive resin (ALB), d) no surface conditioning, control group (CON). Microhybrid resin composite (Filtek Z250) was applied on the conditioned substrate surfaces and photo-polymerized. After storage at 37 degrees C at 100% humidity for 24 h, adhesive interfaces were loaded under shear (1 mm/min) in a universal testing machine. After debonding failure types were analyzed. Data were analyzed using 2-way ANOVA and Tukey's test (alpha = 0.05). SBS results were significantly affected by surface conditioning (p <0.05) and materials (p <0.05). Interaction terms were significant (p <0.05). Biodentine-ALB resulted in significantly higher SBS values (3.96 +/- 1.24) compared to those of other combinations, while ALB and SB2 resulted in no significant difference for ProRoot MTA and Imicryl MTA (p> .05). CSE (1.36 +/- 0.5- 1.98 +/- 0.76) did not significantly increase SBS for all MTA materials compared to the control group (0.8 +/- 0.52- 2 +/- 0.91) (p> 9.05). While CON groups resulted in exclusively adhesive failures, ALB presented the highest incidence of mixed failures for all materials tested (60-100%).