Effect of surface finishing procedures on the color stability of a 3D-printed permanent resin material in artificial saliva at different pH levels: an in vitro study
In vitro study shows glaze coating maintains color stability of 3D-printed permanent resin across varying saliva pH levels, indicating superior resistance to discoloration.
Key Points
To evaluate the color stability and surface changes of an additively manufactured permanent resin material subjected to two finishing procedures across three artificial saliva pH levels.
Fabricated 60 disc-shaped specimens (N=60, 6 groups of n=10) using a digital light processing 3D printer.
Treated specimens with either mechanical polishing alone or mechanical polishing followed by glaze coating, then immersed them in artificial saliva at pH 3, 7, or 12 for 21 days.
Assessed surface topography and composition via FESEM, XRD, and FTIR, and measured color differences using the CIEDE2000 (ΔE00) formula.
Both surface finishing procedure and artificial saliva pH significantly affected color stability independently (p < 0.001 for both), without a significant interaction effect (p = 0.123).
Mechanically polished specimens showed significantly higher ΔE00 values than glazed specimens across all conditions (pH 3: p = 0.003; pH 7: p < 0.001; pH 12: p < 0.001), with the greatest discoloration occurring at pH 12 (p < 0.05).
All glaze-coated groups maintained ΔE00 values below the clinical acceptability threshold (AT = 1.8) under all tested pH conditions.