Palatal Vault Depth Influence on the Flexural Strength of Two Heat Cure Acrylic Denture Base Resins: An in vitro Study

Abstract

Complete dentures often fracture during normal masticatory function. The reason could be due to the shape of the palate, i.e. deep, medium or shallow palatal vault. This in vitro study was performed to determine the relationship of palatal vault depth and flexural strength of two different permanent denture base resins. Edentulous maxillary casts of patients were collected from the department of prosthodontics, among these the cast with the deepest palatal vault was selected. The specimens were then subjected for flexural strength on universal testing machine. The results revealed that the denture bases fabricated on medium palatal vault depth were best in the flexural strength and denture bases on shallow palatal vault depth faired the least. Among the resins the denture bases fabricated using high impact heat cure resin, were better than the denture bases fabricated using regular heat cure resin. All these results were statistically significant except the results between the regular heat cure denture bases and high impact heat cure denture bases fabricated on the deep palatal vault depth. Also the comparison of fracture energies of denture bases fabricated on deep palatal vault with high impact heat cure resin to denture bases fabricated on medium and shallow palatal vaults with high impact heat cure resin were not significant. It was also observed that all the specimens have fractured in the midline. Palatal vault depth significantly affected the flexural strength of heat cure resin. The most frequent mechanical failure of heat cure resin is fracture especially at the midline. The denture bases fabricated using high impact heat cure resin had best flexural strength than the denture bases fabricated using regular heat cure resin which reduced the fractures.