Comparative Evaluation of Flexural and Impact Strengths of Glass Fiber- and Titanium Dioxide Nanoparticle-Reinforced...

This in vitro study aimed to evaluate the effects of glass fiber and titanium dioxide (TiO₂) nanoparticle reinforcement on the flexural and impact strengths of polymethyl methacrylate (PMMA) denture base resin.

Forty rectangular heat-activated acrylic denture base specimens with dimensions of 65 mm × 10 mm × 3.3 mm and 80 mm × 4 mm × 10 mm were fabricated to determine the flexural and impact strengths in accordance with ISO#1567 with an estimated sample size of 10 per group, which was further divided into five for flexural and five for impact strength. Group 1 (Control group) contains conventional heat-activated acrylic denture base resin, Group 2 has 2% TiO₂ nanoparticle-incorporated heat-cured acrylic denture base resin, Group 3 comprises 2% glass fiber-incorporated heat-cured acrylic denture base resin, and Group 4 (Hybrid group) comprises 2% TiO₂+2% glass fiber-incorporated heat-cured acrylic denture base resin. The fabrication followed the compression molding technique and a long curing cycle, and the specimens were tested for flexural and impact strengths.

The hybrid reinforcement group (Group 4; 2% TiO₂ + 2% glass fiber) demonstrated the highest flexural strength (100.32 ± 4.21 MPa), followed by the glass fiber-reinforced group (Group 3; 92.71 ± 3.93 MPa), the TiO₂-reinforced group (Group 2; 84.87 ± 3.78 MPa), and the conventional PMMA group (Group 1; 76.35 ± 2.61 MPa). Similarly, the highest impact strength was observed in Group 4 (5.13 ± 0.43 kJ/m²), followed by Group 3 (4.90 ± 0.39 kJ/m²), Group 2 (3.87 ± 0.45 kJ/m²), and Group 1 (1.48 ± 0.26 kJ/m²).

Hybrid reinforcement with TiO₂ and glass fiber exhibited better flexural and impact strengths than conventional TiO₂ and glass fiber-reinforced PMMA.