Influence of Etching Mode and Composite Type on Bond Strength to Biodentine Using a “No-Wait” Universal Adhesive

Abstract

The purpose of this study was to compare the shear bond strength (SBS) of four resin-based composite materials to a silicate-based cement using a “no-wait” universal bond with self-etch (SE) and etch-and-rinse (ER) modes. Acrylic blocks (n=80, 2mm depth, 5mm diameter central hole) were prepared. The holes were filled with BiodentineTM (BD) and divided into 4 main groups (n=20) according to the composite resin type used: Group FZ250: FiltekTM Z250 Universal Restorative (microhybrid), Group SDR: SDR Plus U Bulk Fill Flowable (low-viscosity bulk-fill), Group FBP: FiltekTM Bulk Fill Posterior (high-viscosity bulk-fill), Group EF: EsFlow™ Universal Flowable Composite (nanohybrid). A ‘no-wait’ universal bond (Clearfil Universal Bond Quick) was used for bonding application. Then each group was divided into 2 subgroups according to the etching mode applied (ER and SE). SBSs were measured and stereomicroscope was used to identify the failure modes. Selected samples of fracture surfaces were imaged by SEM. Tukey’s post-hoc and One-way ANOVA tests were used to analyze data. There were statistically significant differences among the composite groups (p<0.05). When SDR  showed the highest bond strength values in SE (17.13 ± 2.98 MPa) mode, FBP showed the lowest bond strength values in ER (8.89 ± 2.46 MPa) mode. The mean SBS was not different between the SE and ER modes (p> 0.05). The SBS of BD to the resin composites depends on the composite type but  application of the ‘no-wait’ universal bond in different etching modes is regardless of the SBS of BD to resin composites.