Table 2.

Caries Development Rate at the 6-, 12-, and 18-month Follow-ups Among 3 Groups

	Group 1 Control	Group 2 5% NaF	Group 3 38% SDF	P Valuea
Overall	n = 904	n = 872	n = 909
6 months	131 (14.5)	61 (7.0)	88 (9.7)	< 0.001
12 months	151 (16.7)	107 (12.3)	115 (12.7)	0.011
18 months	218 (24.1)	149 (17.1)	247 (27.2)	< 0.001
Sound surface	n = 698	n = 684	n = 673
6 months	94 (13.5)	37 (5.4)	54 (8.0)	< 0.001
12 months	96 (13.8)	61 (8.9)	59 (8.8)	0.003
18 months	142 (20.3)	87 (12.7)	151 (22.4)	< 0.001
Initial caries (RA1-2-3)	n = 206	n = 188	n = 236
6 months	37 (18.0)	24 (12.8)	34 (14.4)	0.332
12 months	55 (26.7)	46 (24.5)	56 (23.7)	0.760
18 months	76 (36.9)	62 (33.0)	96 (40.7)	0.264

Data are presented as n (%)

^aChi-square test