. 2006 Apr;14(2):88–92. doi: 10.1590/S1678-77572006000200005

TABLE 2. Mean ratio of fluoride and phosphate values (F/P x 10^-3) before and after pH-cycling in the removed enamel layers (means ± SD; n = 12).

GROUPS		Control	Varnish	Diamine
Before pH-cycling (F formed)	1^stlayer	^A1.6 ± 0.3^a	^B21.6 ± 4.0^a	^C4.0 ± 0.5^a
	2^ndlayer	^A1.3 ± 0.3^a,b	^B13.2 ± 2.4^b	^C2.4 ± 0.5^b
	3^rdlayer	^A0.9 ± 0.2^b,c	^B7.4 ± 1.5^c	^A1.2 ± 0.3^c,e
After pH-cycling (F retained)	1^stlayer	^A2.0 ± 0.3^a	^B3.4 ± 0.9^d	^A1.7 ± 0.4^d
	2^ndlayer	^A1.4 ± 0.2^a,b	^B1.5 ± 0.4^e	^A0.9 ± 0.1^e
	3^rdlayer	^A0.6 ± 0.1^c	^A0.7 ± 0.1^f	^B0.4 0.1^f
Ratio F formed / F retained	1^stlayer	0,8	6,3	2,3
	2^ndlayer	0,9	8,8	2,6
	3^rdlayer	1,5	10,6	3,0

Mean values followed by different letters are statistically different at 5%. Capital letters show differences between the treatment groups; lower case letters show differences between the enamel layers removed within the same group.

TABLE 2. Mean ratio of fluoride and phosphate values (F/P x 10-3) before and after pH-cycling in the removed enamel layers (means ± SD; n = 12).

TABLE 2. Mean ratio of fluoride and phosphate values (F/P x 10^-3) before and after pH-cycling in the removed enamel layers (means ± SD; n = 12).