Development and performance evaluation of novel preformed primary tooth crowns based on glass fiber-reinforced...

To overcome the limitations of the presently existing preformed crowns on primary teeth in terms of esthetics, mechanical properties, and longevity in the repair of extensive defect areas, an innovative glass fiber-reinforced resin preformed crown on primary teeth has been created and tested in the present research. The material is based on a copolymer system of modified vinyl-epoxy resin and acrylic resin, incorporated with inorganic fillers such as zirconia and reinforced with glass fibers, forming a glass fiber-reinforced vinyl-epoxy polymer (GF-VEP). The in vitro data proved that the physicochemical characteristics (water sorption, solubility, and hardness) and biocompatibility (cytotoxicity and hemolysis) of the material were in line with appropriate industry requirements. GF-VEP crowns had significantly greater compressive and fatigue strength than clinically used preformed resin crowns but less than preformed metal crowns that did not fail under the maximum applied load, when subjected to simulated intraoral conditions. The wear resistance of GF-VEP crowns was not statistically different than preformed resin crowns and significantly lower than preformed metal crowns. GF-VEP crowns also showed significantly higher bonding strength than preformed resin crowns, and no marginal leakage recorded. Even though the bonding strength of preformed metal crowns was not significantly different compared to GF-VEP crowns, dye microleakage was noted at the bonding interface. In general, the GF-VEP crown has a promising overall performance, meeting or exceeding the standards of the existing clinical products, shows potential as an esthetic, reliable, and scalable restorative option to large defects on primary teeth.