Abstract
PURPOSE
To evaluate the color stability of CAD/CAM complete denture resins.
MATERIALS AND METHODS
A total of 176 resin specimens were manufactured from conventional heat-polymerizing (pink: CON$_{HCP}$ : n = 16; tooth-shade: CON$_{HCT}$ : n = 16), CAD/CAM subtractively manufactured (pink: WI$_{MP}$ : n = 16, AV$_{MP}$ : n = 16, ME$_{MP}$ : n = 16, PO$_{MP}$ : n = 16; tooth-shade: AV$_{MT}$ : n = 16, ME$_{MT}$ : n = 16, PO$_{MT}$ : n = 16), and additively manufactured (pink: ND$_{RPP}$ : n = 16; tooth-shade: ND$_{RPT}$ : n = 16) denture resins; four different aging processes (thermal cycling, distilled water, red-wine, and coffee) were used. A spectrophotometer evaluated the color change (ΔE) using two modes of measurements (specular component included (ΔE$_{SCI}$ ) and specular component excluded (ΔE$_{SCE}$ )) recorded at baseline (T$_{0}$ ) and at day#30 (T$_{30}$ ). ANOVA and post hoc tests were used for statistical analysis (alpha = 0.05).
RESULTS
Additively manufactured resins (ND$_{RPP}$ and ND$_{RPT}$ ) demonstrated significant ΔE in comparison to the other groups in all aging media (p < 0.001). WI$_{MP}$ demonstrated higher ΔE$_{SCI}$ in comparison to the other subtractively manufactured groups in distilled water (p < 0.001). In red-wine, AV$_{MT}$ revealed significantly more ΔE$_{SCE}$ than PO$_{MT}$ (p = 0.039). In coffee, the ΔE$_{SCE}$ was higher for CON$_{HCT}$ than ME$_{MT}$ (p = 0.026) and PO$_{MT}$ (p = 0.011). Similarly, in coffee the ΔE$_{SCE}$ for AV$_{MT}$ was higher than PO$_{MT}$ (p = 0.030).
CONCLUSION
Additively manufactured denture resins demonstrated the maximum color change compared to conventional heat-polymerized and CAD/CAM subtractively manufactured denture resins. Furthermore, CAD/CAM subtractively manufactured denture resins were not inferior to conventional resins in terms of color stability.
Gruber, Simon