Effect of different self-etch adhesive application methods on the shear bond strengths of composite resin to dentin

Dental adhesion is a complex phenomenon that has challenged the conventional biomechanical principles applied to Dental Medicine. Many of the advances in aesthetic restorative dentistry are due to dental adhesion: bond of direct resin-based restorations, bond of all ceramic restorations, bond of orthodontic brackets, bond of indirect resin based restorations and improving tooth shape and colour. An adhesive is a material that not only joins two substrates together, but also transfers loads from one surface to another. Therefore, the performance of dental adhesion is measured through adhesion strength This paper aims at investigating the influence of application method and the optional preliminary acid etching on the shear bond strengths of a composite resin to dentin, using self-etch adhesives in single or double layer. Buccal surfaces of 40 extracted human teeth were prepared and dental adhesives were applied on the dentin surfaces. Microshear bond strength increased when double-layer application was used, but this improvement was adhesive dependent. The use of optional preliminary acid etching did not improve significantly the bond strength to dentin.