Table 3.

Mean, standard error, and standard deviation of ΔE in generalized lesions as measured by a spectrophotometer

Group	Number	Maximum	Minimum	Mean	Standard error	Standard deviation
EG0	20	9.30	1.10	4.5590 a	0.53290	2.38318
EG1	20	3.40	0.11	1.4590 b	0.20772	0.92896
EG3	20	3.30	0.32	1.4080 b	0.19241	0.86046
EG6	20	3.00	0.12	1.2846 b	0.19660	0.87923

EG0: Before and immediately after treatment; EG1: One month after treatment and immediately after treatment; EG3: Three months after treatment and immediately after treatment; EG6: Six months after treatment and immediately after treatmentThe ΔE mean values were significantly different between the a and b groups, but were not significantly different within the b group