The potential of PLA based dental models by material extrusion 3D printing: an in vitro study investigating mechanical properties and dimensional accuracy.

Abstract

The rapid advancement of three-dimensional (3D) printing in dentistry has prompted comparisons between the mechanical properties of polylactic acid (PLA) samples fabricated using material extrusion (MEx) and resin samples produced using digital light processing (DLP). This study aims to assess the potential of replacing resin-based models with PLA models in clinical settings by evaluating the mechanical properties and accuracy of MEx-printed PLA and DLP-printed resin samples. The investigated materials include pure PLA, a PLA composite containing gypsum, and a clinically approved resin material. Strength and hardness tests were conducted using custom-made samples measuring 16 × 4 × 2 mm³. Additionally, oral cavity scans were used to generate oral models for each material to assess their accuracy, trueness, and precision. The results indicated that pure PLA exhibited the highest flexural modulus (2055 ± 217.70 MPa) and compression modulus (2.40 ± 0.14 GPa). The PLA-Gypsum composite displayed the highest hardness (19.48 ± 2.12 HV1). As for the trueness of the oral models, there were no statistically significant differences between the models made from the three materials. However, the PLA-Gypsum composite demonstrated the best precision (23.84 ± 4.12 μm). These findings suggest that both PLA materials have significant potential to replace DLP-produced resin models in the clinical applications.