In vitro evaluation of surface roughness, color stability, and color masking of provisional restoration materials for veneers and crowns

Aim: To evaluate surface roughness (SR), color stability (CS), and color masking as assessed through the relative translucency parameter (RTP) of different provisional restoration materials before and after water thermocycling (TC). Materials and methods: Four different provisional materials were selected: acrylic resin, bis-acryl resin, polymethyl methacrylate (PMMA) CAD/CAM blocks, and 3D-printed provisional resin. Samples of 0.6- and 1.3-mm thickness were obtained, and SR, CS, and RTP were determined before and after the samples were submitted to 6000 cycles of TC. A rugosimeter was used to assess SR. Color was determined on white and black backgrounds before and after TC, and color masking was assessed through RTP. CS was determined using a spectrophotometer with the CIEDE2000 formula, before and after TC. Results: SR values before and after TC ranged from -0.01 to 0.28 for 1.3 mm, and from 0.00 to 0.38 for 0.6 mm, respectively. CS (Delta E-00 values) ranged from 0.53 to 4.38 for 1.3 mm, and from 0.70 to 5.66 for 0.6 mm, respectively. The highest value was obtained for 3D-printed resin. Finally, for RTP values, the difference before and after TC ranged from -0.036 to 2.66 for 1.3 mm, and from 0.52 to 2.57 for 0.6 mm, respectively, with the PMMA CAD/CAM block being the material with the lowest values in both cases. Conclusion: Values of SR, CS, and RTP varied among different materials and thicknesses. The overall performance of 3D-printed resin was inferior to that of the other materials. The PMMA CAD/CAM block obtained the overall best values for the conditions tested.