Table 2: SR descriptive statistics in different time intervals between bleaching gel applications.

–	G1 (N = 20)				G2 (N = 20)
Mean	T0	T1	T2	T3	T0	T1	T2	T3
	0.2433A	0.3883B	0.4699C	0.5756D	0.3943a	0.6480b	0.7169c,b	0.8141d,c
	±0.1025	±0.1545	±0.1709	±0.2178	±0.1410	±0.2978	±0.3017	±0.3438