Printing Orientation and Layer Thickness of Nitrogen Post-Cured LCD 3D-Printed Dental Resins

Authors

  • Al-Hakam Jalil Ibrahim Al-Azzawi Institute of Medical Technology, Middle Technical University, Baghdad, Iraq.
  • Hussein Ahmed Al-Khafaji
  • Safa Muneer Abdulsattar
  • Ali F. AlQrimli

DOI:

https://doi.org/10.5195/d3000.2026.1470

Keywords:

Dental Restorations, Dental Composites, Dental Caries

Abstract

This study investigated the impact of two printing orientations (45° and 90°) and two-layer thicknesses (50 µm and 100 µm) on the compressive, tensile, and flexural strengths of a 3D-printed dental resin post-cured in a controlled nitrogen atmosphere. A total of 120 specimens were virtually designed according to ISO standards and then fabricated utilizing an LCD-based 3D printer (SOL, Ackuretta). The specimens were divided into four groups (n = 30/group). All specimens underwent post-curing in a nitrogen (N₂) atmosphere and were tested using a universal testing machine. Data analysis was performed using two-way ANOVA and Tukey's HSD test. Group 2 (45° orientation, 50 µm layer thickness) exhibited significantly higher compressive strength (138.2 ± 11.9 MPa) compared to all other groups (p < 0.001). Tensile strength showed no statistically significant differences among the tested groups (p > 0.05). Specimens printed at a 90° orientation demonstrated significantly higher flexural strength compared to the 45° groups (p < 0.001), with printing orientation exhibiting a greater influence than layer thickness. The compressive and flexural strengths of the tested resin are highly affected by the changes in printing parameters, whereas the tensile strength remained statistically unaffected among the groups. The ideal setting for restorations bearing compressive loads is a 45° orientation with a 50 µm layer thickness, whereas a 90° orientation is highly recommended for long-span restorations subject to flexural loads.

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Published

2026-06-30

Issue

Vol. 14 No. 1 (2026)

Section

Adults & the Elderly

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Copyright (c) 2026 Al-Hakam Jalil Ibrahim Al-Azzawi, Hussein Ahmed Al-Khafaji, Safa Muneer Abdulsattar, Ali F. AlQrimli

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