The Effect of Build Angle on the Mechanical Properties of 3D-Printed Custom Tray Resin Specimens.

The article focuses on evaluating the effect of build angle on the mechanical properties of stereolithography (SLA)-based 3D-printed custom tray resin used in dentistry. Specimens were printed at five different build angles (90°, 120°, 135°, 150°, and 180°) and compared to autopolymerizing (AP) and ultraviolet polymerizing (UV) resin controls. Results showed that build angle did not significantly affect flexural strength (FS) or Vickers hardness (VH) of the 3D-printed trays, though elastic modulus (E) varied with build angle, with the 150° angle showing the highest E among printed groups. The 3D-printed trays demonstrated higher FS than the UV group and comparable FS to the AP group, but lower E and VH than AP resin. Scanning electron microscopy indicated more homogeneous and standardized material properties in 3D-printed specimens compared to controls. The study concludes that SLA-based 3D printing at various build angles can reliably produce custom trays with favorable mechanical properties, though elastic modulus is build angle-dependent.