The effect of different surface treatments on the color stability of the total denture base material produced with A three-dimensional printer

The effect of different surface treatments on the color stability of the total denture base material produced with a three-dimensional printer. Hacettepe University, Faculty of Dentistry, Thesis in Prosthodontics, Ankara, 2021. Digital developments have enabled the use of computer-aided design and computer-aided manufacturing (CAD-CAM) technology and 3D Printers in the design and production of full dentures. Dentures produced with CAD-CAM have many clinical advantages compared to those produced conventionally. One of the measures to be taken to prevent coloration is to reduce the surface roughness. Light-cured Surface Coating (SC) or Polishing (P) process is required on base materials (BM) to reduce surface roughness, but SC and P are not applied to the tissue surfaces of dentures. In our study, it was aimed to comparatively investigate the color stability of denture base materials prepared on polished, surface coated and unpolished surfaces manufactured by conventional method and 3D Printer in different coloring foods (coffee, wine) in-vitro. A total of n=216 samples and n=12 samples for each subgroup were produced. 108 samples were produced by conventional method and 108 samples were produced with 3D printing. Surface roughness (Ra) of all samples was measured. All samples were stored in distilled water, coffee and wine coloring foods for seven days. Color measurement before and after the coloring process was made with a Konica Minolta CM 3600d spectrophotometer, and the color change CIEDE2000(ΔE) values were evaluated comparatively. Obtained data were analyzed with two-way ANOVA. The samples with the unpolished surface produced by 3D Printing showed the highest surface roughness average (23.714 μm Ra). The ΔE00 values of the samples in the group stored in coffee and wine with unpolished surface produced by 3D printing were found to be significantly higher than all sample groups (p<0.05). ΔE values in other groups remained below the thresholds of detectability (1.72) and acceptability (4.08). Surface treatment is required for base materials produced with 3D Printing.