The Impact of Surface Treatments and 3D Printing Machines on the Biaxial Flexural Strength of 3D-Printed Composite Resins

Introduction The use of 3D-printed composite resins, such as BEGO TriniQ, is increasing in restorative dentistry due to their aesthetic and functional potential. However, the biaxial flexural strength of these materials—and the influence of surface treatments and printing machines—requires further investigation to determine their suitability for high-stress clinical applications. Materials and Methods Eighty BEGO TriniQ composite resin specimens were 3D-printed, with 40 produced using the Asiga MAX UV and 40 using the SprintRay Pro printer. Specimens (14 mm diameter, 2 mm thickness) were divided into four treatment groups: control (no treatment), sandblasting, hydrofluoric acid etching, and a combination of both. Biaxial flexural strength was tested using a universal testing machine, and results were analyzed using two-way ANOVA. Results Flexural strength ranged from 103.29 MPa to 113.60 MPa. Although Asiga MAX UV printed specimens showed slightly higher values than SprintRay Pro, the differences were not statistically significant ( p > 0.05). Surface treatments also did not significantly affect flexural strength, and no interaction was observed between surface treatment and printer type. Discussion The findings indicate that neither surface treatments nor the type of 3D printing machine significantly influenced the biaxial flexural strength of BEGO TriniQ resin. This aligns with prior research suggesting that surface treatments may enhance surface characteristics but do not substantially improve mechanical performance in 3D-printed composites. The results emphasize the need for alternative reinforcement strategies to enhance mechanical properties for clinical applications in high-stress areas. Conclusion Surface treatments and 3D printing machines did not significantly impact the biaxial flexural strength of BEGO TriniQ. The material appears suitable for low-stress applications, but further material enhancements are needed to optimize its performance in demanding clinical conditions.