Nanoclay‑reinforced polymethylmethacrylate and its mechanical properties

Abstract

Background: Incorporation of extra fillers into dental resins might enhance their physical
properties. In this study, the tensile and impact strengths of modified heat‑curing acrylic resin
reinforced with nanoclay were investigated.
Materials and Methods: In this experimental study, nanoclay-acrylic resin composite was
prepared by mixing 0.5, 1, and 2 wt% of nanoclay with methacrylate monomer in an ultrasonic
probe, followed by mixing with the polymethylmethacrylate (PMMA) powder. 24 cubic
20 mm × 20 mm × 200‑mm specimens for each test, 18 samples containing nanoclay and 6 samples
for the control group and a total of 48 samples were prepared. The tensile and impact strengths
of the samples were tested according to ISO 527 and 179, respectively. One‑way ANOVA was
used for statistical analysis, followed by multiple comparison tests (Scheffé’s test). Statistical
significance was set at P < 0.05.
Results: The maximum mean tensile and impact strengths were recorded in the control group,
and an acrylic resin containing 2% of nanoclay demonstrated the minimum mean in all the tests.
Increasing the percentage of nanoclay in PMMA compromised the tensile strength (P < 0.05) with
no effect on its impact strength.
Conclusion: Incorporation of nanoclay particles into acrylic resins can adversely affect the
mechanical properties of the final products, and this effect is directly correlated with the
concentration of nanoparticles.
Key Words: Impact, nanoparticles, polymethylmethacrylate, strength, tensile strength