Microtensile bond strength of a dual-cure resin core material to glass and quartz fibre posts

Objectives. To evaluate the microtensile bond strength (μTBS) of a dual-cure resin core material to different regions of fibre posts using different surface treatments. Materials and Methods. Twenty-five silica zirconium glass fibre posts (Snowpost) and 25 quartz fibre posts (Aestheti-Plus) were used and randomly divided into five groups according to the surface treatments: (1) no surface treatment (Control) (2) dual-cure bonding agent, Clearfil Liner Bond 2V (LB) (3) LB followed by light curing for 20 s (LB and C) (4) silane coupling bonding agent agent, Clearfil Photobond with Porcelain Bond Activator (PB+PBA) (5) PB+PBA followed by light curing for 20 s (PB+PBA and LC). Treated posts were cemented into artificial post cavities using a dual-cure composite core material (Clearfil DC Core) and cured for 60 s from the top of the cavity. After 24 h storage in water, each specimen was serially sliced into 8, 0.6×0.6 mm2-thick beams for the μTBS test. The data were divided into three regions (upper/middle/bottom) and analyzed using three-way ANOVA and Dunnetʹs T3 multiple comparisons (α=0.05). Results. There were no significant differences in bond strength between the three regions (p>0.05). The bond strengths were enhanced by the application of a silane coupling agent. For Snowpost, photoirradiation of the dual-cure bonding agent applied to the post surface significantly improved the bond strength (p<0.05), whereas it did not affect the bond strength of Aestheti-Plus post (p>0.05). Conclusion. The bond strength between fibre post and dual-cure resin core material depends upon the type of post and surface treatment. There were no regional differences in μTBS of the bonded post.