Effect of push-out bond strength of a conventional and a bulk-fill composite resin as a biotechnological technique to root dentin of primary anterior teeth

Abstract

This study aimed to compare the push-out bond strength of a bulk-fill and a conventional composite resin to root dentin of primary anterior teeth using a 7th-generation dentin bonding agent. This in vitro study evaluated 24 primary anterior teeth randomly divided into two groups: Filtek P60 conventional and Filtek bulk-fill composite resins. Single Bond Universal adhesive was used for bonding. After filling the coronal part of the canal with composite resin, the teeth were mounted in acrylic resin and sliced to obtain a 1-mm-thick section of each root. Next, the sections underwent the push-out bond strength test. After determining the push-out bond strength, the failure mode was determined under a light microscope at ×40 magnification. The data were analyzed with two-way ANOVA and t-test. The mean push-out bond strength was 13.37±4.40 MPa in the conventional and 5.40±2.91 MPa in the bulk-fill composite resin groups. This difference was statistically significant (P=0.001). In the conventional group, 50% of failures were cohesive in the traditional combined resin group, while in the bulk-fill composite resin group, 75% of losses were mixed. Filtek P60 conventional composite resin and Single Bond Universal 7th-generation bonding agent were determined as appropriate for fabricating intracanal composite posts in primary anterior teeth. Keywords: Push-out, Bond strength, Bulk-fill composite resin, Root dentin, Primary anterior teeth.