Comparison of Color Stability and Surface Roughness of Interim Crowns Fabricated by Conventional, Milling and 3D Printing Methods.

OBJECTIVES: Manufacturing temporary restorations is part of the treatment process in fixed prostheses, which is accomplished by different methods. The aim of this study is to compare the color stability and surface roughness of provisional crowns made by 3D printing, conventional and milling methods. MATERIALS AND METHODS: In this semi-experimental study, 60 provisional crowns were created by conventional, milling, and 3D printing methods (20 samples for each method). Half of the samples in each group were treated with BisCover surface sealant after construction. The surface roughness was checked using a laser profilometer. To determine the color stability, an evaluation was done using a spectrophotometer on the first day and the second and fourth weeks after exposure to the tea solution, and ∆E was calculated using L*a*b* values. Statistical analysis was performed at a significance level of 0.05. RESULTS: The surface roughness in the conventional group was significantly higher than in the milling group (p < 0.05). The surface-treated samples had less surface roughness and more color stability than other samples (p < 0.05). ∆E in the 3D printing group was higher than other groups in all time intervals (p < 0.05). CONCLUSION: The milling method can be considered the best method of making provisional crowns in terms of color stability and surface smoothness. Also, the use of sealing materials can have a significant effect on improving color stability and surface smoothness in provisional crowns made by any method.