Comparative Evaluation of Microtensile Bond Strength of Four Glass-Containing Materials with Primary Teeth Dentin

Background: Bonding to the tooth structure and fluoride release of the restoration are substantial factors to prevent the caries progression in children. Objectives: The aim of this study was to compare micro tensile bond strength of four glass-containing materials with primary teeth dentin. Methods: In this in-vitro study, 16 extracted primary molar were prepared and disinfected with 0.2% thymol solution. The occlusal box was prepared until a thin enamel wall remained and the dentin exposed at the pulpal floor. This enamel wall played the matrix role for placing the restorative materials. The teeth were randomly divided into 4 groups and restored with resin modified glass ionomer (RMGI), giomer, zirconomer and cention N. The teeth were mounted in acrylic mold and entered into a CNC cutting machine to provide specimens with a thickness of 1 × 1 mm. The tensile bond strength of the specimens was calculated by micro tensile measuring device. The failure of the samples (adhesive, cohesive, admix) was observed under a stereomicroscope. The data were analyzed using one-way analysis of variance and Fisher's exact test. Results: There was a significant difference between zirconomer and other groups (P < 0.001), also between giomer and other groups (P < 0.001). There was no significant difference in the pattern of the failure among groups, except RMGI and cention N. Conclusions: The micro-tensile bond of the giomer was the strongest, cention N and RMGI were approximately of equal strength, and zirconomer showed the lowest tensile bond strength.