Influence of Incorporating 5% Weight Titanium Oxide Nanoparticles on Flexural Strength, Micro-Hardness, Surface Roughness and Water Sorption of Dental Self-Cured Acrylic Resin.

Background: Polymethyl methacrylate (PMMA) is used in fabricating acrylic denture bases. Repairing a fractured acrylic denture base can be done by self-cured PMMA, yet this is still a weak point after repair. The aim of this study was to evaluate the effect of incorporating 5% weight titanium oxide nanoparticles (TiO ₂ ) to self-cured PMMA on flexural strength, surface micro-hardness, roughness, and water sorption.
Methods: A total of 160 acrylic-resin specimens were used in this study. They were divided in two main groups; (a) control group, prepared by mixing self-cured PMMA powder to its liquid monomer, (b) treated group, prepared by blending 5% weight TiO ₂ nanoparticles to self-cured PMMA powder then this blend was mixed with the liquid monomer. Flexure strength, surface micro-hardness, roughness, and water sorption were evaluated. Data were analyzed using independent sample t -tests ( p ≤ 0.05).
Results: There was a significant increase in the flexural strength of PMMA of the treated group after the addition of TiO ₂ (137.6 MPa) compared with the control (75.4 MPa) ( p ≤ 0.001). No significant difference between the two groups in terms of micro-hardness ( p = 0.385) and surface roughness ( p = 0.269). Water sorption showed a significant reduction in the treated group ( p ≤ 0.001).
Conclusions: Addition of 5% weight TiO ₂ nanoparticles to the self-cured acrylic resin improved its flexural strength and reduced its water-sorption without impairing the surface micro-hardness and roughness.