IADR Abstract Archives
Effect of Universal Adhesives on Color Shift of Zirconia Veneer
Objectives: Translucent zirconia has been used to make zirconia veneer. MDP-based universal adhesives can improve zirconia bond strength. The aim of this study was to evaluate the effect of universal adhesive on color shift of zirconia veneer.
Methods: Translucent zirconia specimens (9.5 mm x 9.5 mm, 0.7 mm thick) were air-abraded with alumina sand (particle size 50 µm), rinsed with water and air dried. According to the CIE L*a*b* color space, the both sides of zirconia specimen (as baseline) were measured by X-RITE (X-RITE Incorporated). The air-abraded zirconia was then treated with MDP-based universal adhesive (All-Bond Universal, Bisco; or Scotchbond Universal, 3M). The adhesive was air dried and light-polymerized for 10 sec (500mw/cmm2), and the oxygen inhibition layer was wiped off with alcohol. The specimens were immersed in deionized water (37°C), for up to 8 weeks (n=3 for each group). The colors (both zirconia side and adhesive side) before and after immersion in water were measured by X-RITE (X-RITE Incorporated). The color difference (ΔE, zirconia without adhesive as the baseline) was calculated. Statistical analysis was performed by one-way ANOVA, followed by student t-test.
Results: Mean ΔE (standard deviation) of zirconia specimens is shown in Table 1. Mean values with different letters in the same row are statistically different (p<0.05). ΔE less than 2 is normally not noticeable. The color shift of zirconia after application of All-Bond Universal was not noticeable (ΔE < 2), while Scotchbond Universal resulted in higher ΔE (more than 2 on adhesive side, and less than 2 on zirconia side). After immersion in water for 4 weeks, the ΔE of zirconia with Scotchbond Universal was less than 2.
Conclusions: Immediately after adhesive application, the color shift of zirconia veneer might be noticeable (dependent on adhesive), but after immersion in water for several weeks, the color shift of zirconia was not noticeable.
Methods: Translucent zirconia specimens (9.5 mm x 9.5 mm, 0.7 mm thick) were air-abraded with alumina sand (particle size 50 µm), rinsed with water and air dried. According to the CIE L*a*b* color space, the both sides of zirconia specimen (as baseline) were measured by X-RITE (X-RITE Incorporated). The air-abraded zirconia was then treated with MDP-based universal adhesive (All-Bond Universal, Bisco; or Scotchbond Universal, 3M). The adhesive was air dried and light-polymerized for 10 sec (500mw/cmm2), and the oxygen inhibition layer was wiped off with alcohol. The specimens were immersed in deionized water (37°C), for up to 8 weeks (n=3 for each group). The colors (both zirconia side and adhesive side) before and after immersion in water were measured by X-RITE (X-RITE Incorporated). The color difference (ΔE, zirconia without adhesive as the baseline) was calculated. Statistical analysis was performed by one-way ANOVA, followed by student t-test.
Results: Mean ΔE (standard deviation) of zirconia specimens is shown in Table 1. Mean values with different letters in the same row are statistically different (p<0.05). ΔE less than 2 is normally not noticeable. The color shift of zirconia after application of All-Bond Universal was not noticeable (ΔE < 2), while Scotchbond Universal resulted in higher ΔE (more than 2 on adhesive side, and less than 2 on zirconia side). After immersion in water for 4 weeks, the ΔE of zirconia with Scotchbond Universal was less than 2.
Conclusions: Immediately after adhesive application, the color shift of zirconia veneer might be noticeable (dependent on adhesive), but after immersion in water for several weeks, the color shift of zirconia was not noticeable.
