Influência da posição de impressão na isotropia de materiais provisórios produzidos por impressão 3D

Abstract

Introduction: For a long time, the manufacture of temporary prostheses by the conventional technique was used as the gold standard, due to the mechanical characteristics of resins (Polymethylmethacrylate). With technological advances, new ways of obtaining temporary prostheses have emerged, including the making of provisionals with bisacrylic resins and recently the computer-assisted fabrication of provisionals (CAD/CAM) which consists of a layered 3D printing method. Objective: The present study was to evaluate the influence of impression layer orientation on the mechanical property (flexural strength) of temporary prosthetic materials. Material and Method: Specimens were made in bars: 2 x 2 x 25 mm (n=15) (ISO10477), for each group according to the angulation relative to the printing platform (BP0, BP45, BP90). The bars were obtained by drawing in CAD software (Fusion360, Autodesk) and printed on a 3D DLP printer (BASIC PRINTER X, 3DBasic). The tray former software used (Chitu DLP Slicer, CBD Tech) allows different positions of the models of the experimental subgroups on the print tray (0, 45 and 90 degrees with respect to the print tray). These bars were subjected to 3-point bending tests in an Instron Universal Testing machine and evaluated Flexural Strength (RF) and Flexural Modulus (MF) (Kruskal-Wallis ANOVA On Ranks; alpha: 0.05). Results: The RF showed significantly higher values for the BP90 group (114.71 ± 7.61MPa), followed by the BP45 group (90.10 ± 8.45Mpa) and the BP0 group (80.90 ± 4.01MP) (P0.05) and the Flexural Module showing values BP90º (3.74 ± 3.64GPa) followed by the BP45 group (2.85 ± 2.70GPa) and BP0º (2.52±2.44GPa). Conclusion: The groups showed significant statistical differences, which shows the non-isotropic behavior of the restorative material manufactured by 3D printing, which suggests that the choice of the angulation of the impressions can determine the applicability according to the characteristics and function of the object to be printed. .