Flexural strength and elastic modulus evaluation of structures made by conventional PMMA and PMMA reinforced with graphene
Abstract. – OBJECTIVE: The aim of this study
was to compare both the elastic modulus (EM)
and the flexural strength (FS) of two materials
used in dental prosthesis, namely polymethylmethacrylate (PMMA) and polymethylmethacrylate reinforced with graphene (G-PMMA).
MATERIALS AND METHODS: Twenty rectangular samples were manufactured by a milling machine and divided into two groups (n=
10/group): Group 1, PMMA; Group 2, G-PMMA.
The specimens were subjected to a three-point
bending test conducted in the elastic range to
evaluate EM. A similar test was protracted until
fracture to evaluate FS. Data on EM and FS were
statistically analyzed with independent-samples t-test in order to compare the two groups.
A scanning electron microscope (SEM) (5.00 kx
and 1.00 kx magnification) was used to evaluate
the morphology of sample’s fracture.
RESULTS: Compared to PMMA samples, each
G-PMMA sample showed significantly higher
values of FS (p <0.001) and EM (p <0.001). SEM
images analysis showed an inhomogeneous
fracture morphology in G-PMMA samples.
CONCLUSIONS: The results show that G-PMMA is a promising material to be used for prosthetic purposes. This is demonstrated by a significant increase in both peak load and bending
stiffness, resulting from the bending test performed on G-PMMA samples. Furthermore, the
latter exhibit greater homogeneity in their mechanical behavior, supporting the potential value of this material in dental prosthesis.