The Effect of Gastric Acid and Material Type on the Surface Roughness of Additive and Subtractive Manufacturing...

To examine the effect of gastric acid on the surface roughness of additive and subtractive manufacturing resin.

In this study, two subtractive-manufacturing CAD/CAM resin nanoceramics (Cerasmart 270 [CS], Lava Ultimate [LU]) and two additive-manufacturing 3D-printing permanent resins (VarseoSmile Crownplus [VSP], Crowntec [CT]) were used. CS and LU samples were turned into 10-mm-diameter cylinders with a scraper and cut into 2-mm slices on the cutting device. CT and VSP samples were produced on a 3D printer (2-mm thickness, 10-mm diameter; n = 15). All samples were exposed to a cycle of 60 seconds of gastric acid, 5 seconds of distilled water, and 30 minutes of artificial saliva, six times a day for 10 days. Surface roughness mean (Ra) and depth (Rz) were measured with a contact profilometer at baseline and after gastric acid cycling. Data were analyzed using SPSS (version 22.0), one-way ANOVA, post-hoc Tukey, and independent t tests (P < .05).

Ra and Rz values of CT and VSP were significantly higher than CS and LU at baseline and after the gastric acid cycle (P < .05). After the gastric acid cycle, the Ra and Rz values of all materials increased significantly compared to baseline (P < .05), but the Ra values of all materials were at a clinically acceptable level (< 0.2 µm).

Although additive-manufacturing 3D-printing permanent resins offered higher roughness values, they were still at a clinically acceptable level. Therefore, they can be used as an alternative to subtractive-manufacturing CAD/CAM resin nanoceramics.