Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Evaluation of the microhardness of different 3D printing resins for denture base
Submission Author:
Ana Paula MACEDO , SP
Co-Authors:
Ana Paula MACEDO, Sarah Ribeiro Cruz Araújo, Milena Moreira Lima , Anselmo Agostinho Simionato, Valéria Pagnano, Rossana Almeida
Presenter: Ana Paula MACEDO
doi://10.26678/ABCM.COBEM2023.COB2023-1905
Abstract
The main material used for the manufacture of complete dentures is a heat-curing acrylic resin. The technological and scientific evolution in all areas of knowledge allows dentistry to absorb technologies such as additive manufacturing, ensuring that the clinical results obtained are safer and more predictable. However, because these materials are recent in use in dentistry, there are no reports on their mechanical properties such as Microhardness, directly related to wear resistance, which is important in complete dentures. To evaluate the Knoop Microhardness of two 3D printing resins for complete denture base in comparison with the heat-curing acrylic resin. Sixty circular specimens (20.0 x 3.0 mm) were made using two 3D printing resins (BioDenture and BB Base) and a heat-curing acrylic resin as control. The printed specimens were designed in the software Rhinoceros 6 and exported in .stl format to the software CHITUBOX Basic 1.9.1. In CHITUBOX the positioning of supports and slicing of the samples were performed, according to manufacturer's instructions. After the impression procedure, the specimens were washed in isopropyl alcohol. The post-curing process for complementary photopolymerization was performed with a specific post-curing booth, according to manufacturer's instructions. The heat-curing acrylic resin specimens were made from a teflon matrix to obtain wax patterns, subsequently included in metal muffles, using stone gypsum and solid Vaseline. Gypsum/resin insulator was applied over the gypsum. The heat-curing acrylic resin was manipulated, placed in the muffle, pressed, and polymerized according to the manufacturer's instructions. All specimens were sanded with a horizontal polisher in a sequence of sandpapers (320, 600, 1200, 2000). For the final polishing, the Alumina (1 μm) in suspension and then with calcium carbonate water solution were used. Five indentations per specimen were made using a Knoop diamond penetrator in the microhardness test. The applied load was 245.2mN for 5 seconds. The data were tested for normality and the one-way ANOVA and Tukey post-test were performed (α = 0.05). Statistically significant difference was observed among all resins (p < 0.001). The highest values (mean; standard deviation) were observed for the heat-curing resin (18.8; 0.5), followed by BB base (17.7; 1.8) and the lowest values for Biodenture (12.5; 1.2). In conclusion, Heat-curing acrylic resin shows higher Knoop microhardness than 3D printing resins. The use of these new 3D printing resins can decrease the durability of the complete denture.
Keywords
Knoop Microhardness, 3D printing resins, heat-curing acrylic resin, denture
