Mechanical Characterization of Dental Prostheses Manufactured with PMMA-Graphene Composites

Miquel Punset; Aritza Brizuela; Esteban Pérez-Pevida; Mariano Herrero-Climent; José Maria Manero; Javier Gil

doi:10.3390/ma15155391

Mechanical Characterization of Dental Prostheses Manufactured with PMMA-Graphene Composites

Materials (Basel). 2022 Aug 5;15(15):5391. doi: 10.3390/ma15155391.

Authors

Miquel Punset^{1

2

3}, Aritza Brizuela⁴, Esteban Pérez-Pevida⁴, Mariano Herrero-Climent⁵, José Maria Manero^{1

2}, Javier Gil⁶

Affiliations

¹ Biomaterials, Biomechanics and Tissue Engineering Group (BBT), Department of Materials Science and Engineering, Universitat Politècnica de Catalunya (UPC), Av. Eduard Maristany 16, 08019 Barcelona, Spain.
² Barcelona Research Center in Multiscale Science and Engineering, Technical University of Catalonia (UPC), Av. Eduard Maristany 10-14, 08019 Barcelona, Spain.
³ UPC Innovation and Technology Center (CIT-UPC), Technical University of Catalonia (UPC), C. Jordi Girona 3-1, 08034 Barcelona, Spain.
⁴ Facultad de Odontología, Universidad Europea Miguel de Cervantes, C/del Padre Julio Chevalier 2., 47012 Valladolid, Spain.
⁵ Porto Dental Institute, 4150-518 Oporto, Portugal.
⁶ Bioengineering Institute of Technology, International University of Catalonia, Josep Trueta s/n., 08195 Barcelona, Spain.

Abstract

The use of a PMMA composite with graphene is being commercialized for application as dental prostheses. The different proportions of fibers provide a wide range of colors that favors dental esthetics in prostheses. However, there are no studies that have explained the influence that graphene has on the mechanical properties. In this contribution, we studied the PMMA and PMMA material with graphene fibers (PMMA-G) in the form of discs as supplied for machining. The presence of graphene fibers has been studied by Raman spectroscopy and the Shore hardness and Vickers micro hardness were determined. Mechanical compression tests were carried out to obtain the values of maximum strength and Young’s modulus (E) and by means of pin-on-disc wear tests, the specific wear rate and the friction coefficients were determined following the established international standards. Finally, the samples were characterized by field emission scanning electron microscopy (FESEM) to characterize the graphene’s morphology inside the PMMA. The results showed the presence of graphene in PMMA and was estimated in an amount of 0.1027% by weight in G-PMMA. The Shore hardness and Vickers microhardness values did not show statistically significant differences. Differences were observed in the compression maximum strength (129.43 MPa for PMMA and 140.23 for PMMA-G) and E values (2.01 for PMMA and 2.89 GPa for PMMA-G) as well as in the lower wear rate for the G-PMMA samples (1.93 × 10−7 for PMMA and 1.33 × 10−7 mm3/N·m) with a p < 0.005. The coefficients of friction for PMMA-G decreased from 0.4032 for PMMA to 0.4001 for PMMA-G. From the results obtained, a slight content in graphene produced a significant improvement in the mechanical properties that could be observed in the prosthesis material. Therefore, we can state that the main attraction of this material for dental prosthesis is its esthetics.

Keywords: PMMA; composites; dental materials; graphene; mechanical properties; prosthetic materials.

Grants and funding

The work was supported by the Spanish government and the Ministry of Science and Innovation of Spain by the research project numbers RTI2018–098075–B–C21 and RTI2018–098075–BC22, cofounded by the EU through the European Regional Development Funds (MINECO–FEDER, EU). The authors also acknowledge the Generalitat de Catalunya for funding through the projects 2017SGR–1165 and 2017SGR708.