Effect of Printing Angle and Resin Type on the Flexural Strength of 3D-Printed Dental Materials

Three-dimensional printing is growing rapidly in applied dentistry. To print faster, increase workflow, and minimise resin consumption, it is important to use the right printer and correct printing orientation. This report aims to analyse whether different printing orientations and types of printing materials could affect the flexural strength of a series of photopolymerisable resin samples. Seven different dental light-curing resins (Keyguide, C&B, Ivory, Vertysguide, Bite, Tera, and Nextdent Cast) and a single modern digital light processing (DLP) 3D printer (Moon Night) were used for this purpose. Different printing orientations (0°, 45°, and 90°) were evaluated. The resin specimens were designed using 3D Builder 20.0.4.0, MeshMixer 3.5.0 and Chitubox software 2.0.8. A total of 15 specimens (five for each orientation evaluated) in the shape of a rectangular parallelepiped with dimensions of 2 mm × 2 mm × 25 mm were produced for each of the seven selected resin materials with the Moon Night printer. After printing and post-processing (MoonWash 2 and MoonLight 2), each resin specimen was subjected to a mechanical test with a universal testing machine. After breaking the specimen, the flexural strength values were recorded using Bluehill computer software (Instron Corporation, Canton, MA, USA). According to the obtained results, the build angle does not affect the flexural strength of the printed products, whereas the difference occurs due to the different printing materials used.