Evaluation of the bond strength, surface roughness and wettability between 3D-printed denture base resin to denture lining material to different surface treatments.

BACKGROUND: The low bond strength between 3D-printed denture base resin and denture lining material is due to the difference in chemical structure, which justifies the use of methods to increase such bond. This study aims to examine the influence of different surface treatments on the bond strength, surface roughness, and wettability between 3D-printed denture resin and denture lining material. MATERIAL AND METHODS: Bar-shaped (75×10×10 mm) and square-shaped (10×10×3 mm) specimens were manufactured using heat-polymerized (HT) (VIPICRIL Plus) and 3D-printed (3D) (Prizma 3D Bio Denture) denture base resin. The bar specimens were sectioned, removing 3 mm from the center to facilitate the insertion of the denture lining material (Ufi Gel SC). Specimens were subjected to three surface treatments (n=15): no treatment (CT), immersion in monomer for 180 seconds (M), and airborne-particle abrasion oxide with 50 µm aluminum oxide (AP). The tensile bond strength was measured at a rate of 5mm/min before and after subjecting the specimens to thermocycling (10 000 cycles). The square-shaped specimens were used to assess average surface roughness (Ra) and wettability (°). Data analysis was performed using a 3-way ANOVA with Tukey's post-test (P<.05). RESULTS: The treatment of the 3D-printed denture base resin (1.200±0.486) with AP made the bond strength to the denture lining material similar to HT denture base resin (1.314±0.249), without the negative impact of aging. In contrast, M treatment increased the bond strength of both resins to the denture lining material (HT: 2.076±0.463; 3D: 1.534±0.484). Treatment with M provided a lower contact angle for the 3D and HT denture base resin, while the HT denture base resin presented a greater surface roughness for M and AP, compared to 3D. CONCLUSIONS: The 3D-printed denture base resin should undergo immersion in monomer treatment to enhance its bond strength with the denture lining material. Key words:Denture lining material, Complete denture, Manufactured material, Denture base resin, Bond strength.