Effects of solvent type and UV post-cure time on 3D-printed restorative polymers

This study evaluated the impact of different solvents and UV post-curing times on properties of 3D printing resins for provisional restorations.

The post-processing methods were tested using two solvents (isopropyl alcohol or absolute ethanol) and three UV times (5, 10, or 30 min). The resins tested were Resilab 3D Temp, Printax Temp, and Prizma Bioprov. Microhardness (kgf/mm²), fracture toughness (K_IC, MPa√m), surface roughness (Ra, µm), gloss (gloss units), and degree of CC conversion (%DC) were measured (n = 8). All response variables were collected from the same specimen. The specimens were 3D printed using an SLA/LCD printer (150° angulation, 50 µm layer thickness). Light exposure times were adjusted for each material, and the post-processing methods were applied using an all-in-one machine immediately after printing. Data were analyzed using Three-Way ANOVA (α = 0.05).

Microhardness was affected by UV post-cure time and 3D resin. Resilab showed higher microhardness with isopropyl alcohol and 30-min UV time, while Printax had higher microhardness with absolute ethanol. K_IC was influenced by solvent type, UV time, and 3D resin, with varying effects on different resins. Roughness was affected by 3D resin and UV time, but no significant differences were seen for Resilab or Prizma. Gloss was influenced by 3D resin, and for Prizma, it was lower with specific solvent/UV time combinations. DC was influenced by 3D resin, with each resin behaving differently.

Tailoring the combination of 3D resin, solvent washing type, and UV post-curing time is important to achieve optimal mechanical and aesthetic outcomes for restorations.