Volume 6 , Issue 2 , December 2019 , Pages 21-30
Lazyan L. Raouf 1 ; Souza A. Faraj 1 ; Bruska A. Azhdar 2
1 Department of Prosthodontics, College of Dentistry, University of Sulaimani, Sulaimani, Iraq.
2 Nanotechnology Research Laboratory, Department of Physics, College of Science, University of Sulaimani, Sulaimani, Iraq.
Objective: The aim of this study was to investigate the effect of zirconium oxide (ZrO2) nanoparticle dispersion on the flexural property
of heat-cure polymethylmethacrylate denture base material.
Methods: Eighty specimens were divided into 10 groups of eight specimens; Group 1 unreinforced acrylic, group 2: treated with
ethanol alcohol, Groups 3,4,5 and 6 reinforced acrylic specimens with 1, 3, 5, and 7 wt% of untreated zirconium oxide nanoparticle (uZrO2) and Groups 7,8,9 and 10 reinforced acrylic specimens with treated and sonicated zirconium oxide nanoparticle in ethanol alcohol
(t-ZrO2). X-ray diffraction test (XRD) was used to study the dispersion quality of the tested specimens, and universal testing machine
was used to evaluate flexural strength and flexural modulus. SPSS software program used to compare groups results statistically.
Results: The results revealed significant decrease in flexural strength with u-ZrO2 nanoparticle addition in different concentration
groups (p<0.05), while with t-ZrO2 nanoparticle addition, above 3 wt% statistically significant decrease was noted as compared to the
conventional group. However, the flexural modulus increased with increasing the both of u-ZrO2 and t-ZrO2 nanoparticles addition.
XRD results showed better dispersion quality of the t-ZrO2 than u-ZrO2 throughout the acrylic resin denture base material.
Conclusions: Flexural strength decreased inversely with increasing u-ZrO2 concentration, while it decreases significantly above 3 wt%
of t-ZrO2 nanoparticle concentration. The flexural modulus increased with increasing both of u-ZrO2 and t-ZrO2 nanoparticles. Reduced
nanoparticle’s cluster size of t-ZrO2 allows more nanofiller to be incorporated to denture base materials with less adverse effect on the
mechanical properties.