Comparative Evaluation of Surface Hardness of Different Resin-Modified Glass Ionomers and a Compomer

Due to the practical problems and time restriction issues in treating dental problems in children, there is a noticeable demand for the application of a convenient handling restorative material with acceptable physical- mechanical properties. The aim of this investigation was to evaluate Vickers microhardness of four tooth-colored restorative materials as a determining mechanical property in pediatric dental care. Materials and methods: In this in vitro study, 20 samples were established for each Fuji II LC, Ionoseal, Ionolux, and Ionosit restorative dental materials by a single operator using polyvinyl chloride cubical molds (4 × 4 mm side length and 2 mm height). After polymerization by using a halogen visible-light polymerization unit, they were stored in artificial saliva at 37°C for 24 hours and then wet finished with a sequence of silicon carbide grit papers. Fuji II LC was used as the reference material for the resin-modified glass ionomer cements. Vickers hardness of all samples was assessed. The recorded data were analyzed by the Kruskal–Wallis test followed by the Mann–Whitney U test at the P < 0.05 significance level. Results:Besides the statistical difference between the four groups, the mean values of surface microhardness of Fuji II LC and Ionoseal were significantly higher than the powder-liquid Ionolux. The hardness value of compomer and Ionoseal was different but the difference was not statistically significant. Conclusion: On the basis of the importance of microhardness property in the clinical success of a restorative material, the extensively investigated microhardness value of the Ionoseal material in addition to its ease of handling and benefits of time saving may account for its consideration as a reliable restorative material in the dental care for children.