An In Vitro Study to Assess the Effect of Cigarette Smoke on Color Stability and Surface Roughness of 3D Printed, Milled, and Traditional Provisional Crown and Bridge Materials.

Objectives To assess the influence of cigarette smoke (CS) on the color and surface roughness of 3D printed, milled, and traditionally fabricated provisional crown and bridge (PC&B) materials. Materials and methods 112 disc-shaped samples were made employing four techniques and materials (28 per group) to fabricate PC&B prostheses. Specimens were fabricated using standard protocols, such as 3D printing, milling, conventional bis-acrylic resin, and traditional autopolymerizing polymethyl methacrylate (PMMA) resin. After preliminary color and surface roughness recording, each group specimen was divided randomly into two subgroups (14 each). The artificial saliva acted as the storage media for the control group specimens for 30 days, and test group specimens were subjected to CS in a customized smoking chamber (10 minutes twice daily, for 30 minutes). Final color and surface roughness measurements were made. The change in color (∆E00) and surface roughness (∆Sa) were calculated, and the data was tabulated for analysis.  Statistical analysis One-way analysis of variance was used to analyze the change in color and surface roughness. Post-hoc Tukey HSD test was used for comparison between groups. Results The mean ΔE00 and ∆Sa were higher among groups exposed to CS than those exposed to artificial saliva. The maximum change in color was recorded in the autopolymerizing PMMA, whereas the 3D printed resins recorded the minimal change. The traditional bis-acrylic resin recorded the maximum mean surface roughness change, while the milled resin recorded the least change. Conclusions Within the study limitations, it can be inferred that when exposed to CS, 3D printed and milled PC&B materials have superior color stability and displayed less change in surface roughness when equated with traditional bis-acrylic and autopolymerizing PMMA resins.