Evaluation of color changes produced by different bleaching techniques on stained two different ceramic materials

Abstract

Objective The aim of this in vitro study was to evaluate the color changes produced by different bleaching techniques on two different stained ceramic materials. Material and methods The total 40 specimens of IPS e.max and shofu were stained by immersing in coffee 30 min daily for 14 days and color assessment was done by spectrophotometer, then the specimens were divided into two subgroups according to the bleaching technique home bleaching (white smile) and office bleaching (pola office), the bleaching was done according to manufacturer instruction for pola office: an adequate thickness of the bleaching agent by the brush was applied for 8 min. This procedure was repeated for 3 times. And for home bleaching (white smile): specimens were placed in the mold to receive home bleaching agent by immersion 60 min daily for 6 days. Then the color was assessed after bleaching procedure to determine the changes. The data were statistically analyzed by one-way ANOVA test and Correlation analysis. Results Shofu recorded higher staining affinity with mean value 6.72 ± 2.33 than (IPS) e.max group with mean value 4.92 ± 2.08. For bleaching: Shofu HC group home bleaching group recorded higher bleaching affinity with mean value 7.86 ± 1.93 whereas shofu office bleaching group recorded mean value 6.04 ± 0.65. As for e.max home bleaching group recorded also higher ∆ E with mean value 5.68 ± 0.86 whereas e.max office bleaching group recorded mean value 4.37 ± 1.01. And a strong relation was recorded between ∆E1 and ∆E2 in all groups as r greater than 0.5. Conclusion Shofu HC and IPS e.max showed affinity to staining but Shofu HC showed higher stain ability than IPS e.max, Office and home bleaching techniques affected the color of both ceramics materials and home bleaching showed higher significant difference. And Shofu HC showed higher color change after home and office bleaching than IPS e.max.