A Novel Low-Shrinkage Resin for 3D Printing

Abstract

Objective: To evaluate the shrinkage, accuracy, and mechanical properties of a newly developed photo-polymerizable resin material for 3D printing dental applications and compare it with three commercially available resins.

Methods: An experimental novel proprietary resin material for 3D printing was formulated. This new resin, Die and Model Tan (SprintRay), Formlabs Grey (FormLabs), and LCD Grey (Roxel 3D) were evaluated and tested for volumetric shrinkage, accuracy, and flexural and tensile properties. Volumetric shrinkage was measured using the AcuVol video imaging method. The accuracy of the 3D printed objects through the DLP (digital light processing) printing system was determined by the 3D deviation between the scanned model and the original computer-aided-design (CAD) digital model. Parallelepiped specimens (2 × 2 × 25 mm, n = 5) were printed for flexural strength, flexural modulus, and modulus of resilience and measured in accordance with ISO-4049. Dumbbell-shaped specimens (Type V, n = 5) were printed to investigate the tensile strength and tested according to ASTM-D638. Data were analyzed using one-way ANOVA and post-hoc Tukey tests (p ≤ 0.05).

Results: The experimental resin exhibited significantly lower volumetric shrinkage and significantly higher accuracy than the other commercially available resins (p < 0.001). The experimental resin showed flexural strength, flexural modulus, and tensile strength similar to Die and Model Tan resin (SprintRay) (p > 0.05), and these parameters were significantly higher than those of Formlabs Grey resin (Formlabs) and lower than those of LCD Grey resin (Roxel3D)(p <0.001).

Conclusion: The newly formulated 3D printing resin demonstrated lower volumetric shrinkage, high accuracy, and adequate mechanical properties compared to the commercially available resin materials.

Clinical significance: The new 3D printed objects exhibited higher accuracy, good stability over time, and adequate mechanical properties; hence, it is a good candidate for modeling applications for restoration, orthodontics and implants.

Keywords: 3D printing; Accuracy; Additive manufacturing; Mechanical properties; Resin; Shrinkage.