Effect of Bleaching on Color Change and Surface Topography of Composite Restorations

Table 2

Total discoloration (Δ𝐸) for all test samples at three different time intervals using one way ANOVA and multiple comparison test of total discoloration (Δ𝐸) between different test materials using Bon Ferroni correction.

Group	Baseline- staining Δ𝐸1	Staining-bleaching Δ𝐸2	Bleaching-baseline Δ𝐸3	Intragroup significance value (Δ𝐸3 versus Δ𝐸1)
Filtek Z350	6.3 (1.71)*	5.76 (1.19)	1.97 (1.39)*	* 𝑃=.000
Esthet X	6.71 (1.98)**	6.58 (1.77)	1.79 (1.35)**	** 𝑃=.002
Admira	4.42 (1.10)^NS	6.79 (2.09)	3.02 (1.6)^NS	^NS𝑃=.18

Esthet X versus Admira—𝑃=.013. Significant = 𝑃<.001, NS = 𝑃>.05
The calculations of Δ𝐸 were as follows:
Δ𝐸₁=[(Δ𝐿2−Δ𝐿1)²+(Δ𝑎2−Δ𝑎1)²+(Δ𝑏2−Δ𝑏1)²]^1/2
Δ𝐸₂=[(Δ𝐿3−Δ𝐿2)²+(Δ𝑎3−Δ𝑎2)²+(Δ𝑏3−Δ𝑏2)²]^1/2
Δ𝐸₃=[(Δ𝐿3−Δ𝐿1)²+(Δ𝑎3−Δ𝑎1)²+(Δ𝑏3−Δ𝑏1)²]^1/2