Improving the strength properties of denture base acrylic resins using hibiscus sabdariffa natural fiber

Various materials have been reported to improve the strength and fatigue resistance of poly methyl methacrylate (PMMA) denture base resins, however there is limited evidence on using natural fibers. This study determined the flexural and impact strengths of Hibiscus sabdariffa fiber-reinforced PMMA acrylic resins. From the 50 PMMA specimens fabricated, 40 were reinforced with Hibiscus sabdariffa fibers of different weight percentages (wt%) and 10 were unreinforced. There were two sample groups, each consisting of 25 PMMA specimens for flexural and impact strengths testing, respectively. Statistically, ANOVA and Bonferroni tests showed significant differences among the groups. Flexural strength results revealed that PMMA reinforced with 7.5 wt% fibers produced the highest mean value (101.20 ±3.654) MPa, followed by the 10 wt% (88.67±13.752) MPa, unreinforced (83.55±0.618) MPa, 5 wt% (75.58 ±3.676) MPa, and 2.5 wt% (68.84 ±4.293) MPa. Impact test results revealed that PMMA reinforced with 7.5 wt% fibers had the highest mean value (32.01±0.015) KJ/M2, followed by 10 wt% (24.48 ±0.010) KJ/M2, 5 wt% (23.54 ±0.006) KJ/M2, 2.5 wt% (17.89 ±0.006) KJ/M2 and the unreinforced (13.12 ±0.003) KJ/M2. Essentially, the inclusion of 7.5 wt% Hibiscus sabdariffa fibers improved the strength properties of PMMA denture base resins.