Effect of Addition of Sapphire (Aluminium Oxide) or Silver Fillers on the Flexural Strength Thermal Diffusivity and Water Sorption of Heat Polymerized Acrylic Resins
ABSTRACT Purpose This work was undertaken to investigate the effect of adding sapphire (aluminium oxide) or silver filler particles on the flexural strength, thermal diffusivity and water sorption of polymethylmethacrylate (PMMA) resin. Materials and methods A total of 90 samples were fabricated and divided into three groups (n = 30): Group I-PMMA (control), group II- PMMA with sapphire fillers and group III-PMMA with silver fillers. Each group samples were divided into three subgroups (n=10) according to the properties evaluated. Sub group I: Flexural strength samples (rectangular bars of 65 ⨯ 10 ⨯ 2.5 mm dimensions), sub group II: Thermal diffusivity samples (cylindrical shaped of 9 ⨯ 9 mm dimensions) and sub group III: Water sorption samples (disk shaped of dimensions 50 ⨯ 0.5 mm). Results were analyzed by one-way ANOVA and Bonferroni correction tests (p < 0.05). Results The mean flexural strength of group II (116.5 MPa) was significantly higher while that of group III (77.91 MPa) significantly lower than the control group (88.63 MPa). The mean thermal diffusivities of both group II (0.079 mm/sec) and III (0.123 mm/sec) were found to be significantly higher than the control group (0.062 mm/sec). Both group II (0.59 mg/cm) and group III (0.53 mg/cm) showed significantly less mean water sorption than the control group (0.65 mg/cm). Conclusion As compared to silver fillers, sapphire fillers are purported to be better fillers for the reinforcement of polymethylmethacrylate resin. This is because they have potential as added components in denture bases to provide increased flexural strength, thermal diffusivity and decreased water sorption.