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Objectives: To evaluate the flexural strength of a heat-cured denture base polymer relined with different thickness of self-cured relining materials.
Materials and methods: Two different thickness ratios (1.5:1.5 and 2:1) of one heat-cured denture base polymer (ProBase Hot) to three self-cured hard relining materials (Kooliner PEMA, Tokuyama Rebase II PEMA and Unifast Trad PMM) were examined. Three point bending flexural test was applied on the relined specimens (64mm ×10mm×3mm) and on intact specimens of similar dimension with 3, 2 and 1.5 mm thickness. Each specimen was immersed in 37±1 ͦC distilled water for 43±2 hours prior to relining and testing. Statistical analysis was performed using one-way ANOVA and Tukey’s HSD post-hos test (α = 0.05).
Results: There were significant differences in flexural strength among denture base relined with different materials, in both thickness ratios. The specimens relined with Unifast Trad possessed the highest flexural strengths (60.77 ± 5.88 MPa), while those relined using Tokuyama Rebase II displayed the lowest strength (40.55 ± 1.04 MPa). No significant differences were found when ProBase Hot was relined with different thickness (1.5mm and 1mm) of Tokuyama Rebase II (40.55 ± 1.04 MPa and 44.25 ± 1.79 MPa), Kooliner (45.80 ± 2.25 MPa and 50.20 ± 2.95 MPa), and Unifast Trad (60.77 ± 5.88 MPa and 60.77 ± 5.88 MPa).
Conclusions: Self-cured hard relining materials have an effect on the flexural strength of relined denture base. Flexural strength of denture base relined with PMMA is higher than that relined with PEMA. Denture Different thickness ratio of denture relining polymer had no effect on flexural strength of relined denture base.
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