Effects of Silane Treated Filler on the Properties of Zirconia-PMMA Nanocomposites

Objectives: Purpose: The aim of this study was to investigate the flexural strength, flexural modulus and surface hardness of high impact heat-cured acrylic denture resin reinforced with silanized and non-silanized zirconia (ZrO₂) nanoparticles.
Methods: Materials and Methods: Seventy five high impact heat-cured acrylic resin specimens reinforced with zirconia were fabricated. Ten specimens were used for measuring the flexural strength and flexural modulus and another five specimens for measuring surface hardness. All the specimens were divided into three groups: Group 1 was the control group with no zirconia, Group 2 was reinforced with 3wt% of non-slianized zirconia nanoparticles and Group 3 was reinforced with 3wt% of slianized zirconia nanoparticles. The dimensions of the specimens were 65 mm × 10 mm × 2.50 mm, for conducting flexural strength and modulus (Universal testing machine; Zwick/Roell Z020 Leominster, UK) and surface hardness (FM-700, Future Tech Corp., Japan) tests accordance to British International Standard Organization (BS EN ISO 20795-1:2008).
Results: Results: The results showed that the mean values of flexural strength (83.58 ± 6.2 MPa) and surface hardness (20.14 ± 2.31) were significantly increased (P < 0.05). However, flexural modulus (2313 ± 161 MPa) was significantly decreased (P > 0.05) for HI-PMMA/silanized zirconia nanocomposites when compared to the samples with non-silanized zirconia (59.91 ± 7.1 MPa) (2207 ± 252 MPa) (15.07 ± 0.29) and the control group.
Conclusions: Conclusion: Silane treatment of zirconia nanofiller can improve the flexural strength and surface hardness properties of HI-PMMA/ZrO₂ nanocomposite for longer service life as a denture base.