. 2019 Apr 5;14(4):e0214948. doi: 10.1371/journal.pone.0214948

Table 2. ANOVA applied to the mean (and standard deviation) of the surface roughness (μm) for the different times of application of 10% carbamide peroxide.

	Times of Application
	T1	T2	T3	T4
Mean (Standard deviation)	244.14 (±44.12)^a	234.86 (±49.21)^a	219.86 (±30.51)^a	194.96 (±37.45)^b

Different letters indicate statistical difference at 5%.

T1, control group; T2, 14 days of CP 10% application; T3, 21 days of CP 10% application; T4, 28 days of CP 10% application.