Incipient caries rate D1, D2 changingof the two groups by time Incipient caries rate D1, D2 p (prtest test) Pre - intervention n (%) After 6 months n (%) After 12 months n (%) After 18 months n (%) Interven tion group (n=197) Male (n=93) 64 (68.8) 65 (69.9) 37 (40.7) 32 (35.2) p12 > 0.05 p13<0.001 p13<0.001 Female (n=104) 64 (61.5) 75 (72.1) 46 (44.2) 44 (42.3) p12 > 0.05 p13 < 0.01 p14 < 0.01 Total 128 (65.0) 140 (71.1) 83 (42.6) 76 (39.0) p12 > 0.05 p13<0.001 p14<0.001 Control group (n=247) Male (n=128) 59 (46.1) 74 (57.8) 83 (64.8) 89 (69.5) p12 < 0.05 p13 < 0.01 p14>0.001 Female (n=119) 62 (52.1) 85 (71.4) 94 (79.0) 86 (72.3) p12 < 0.01 p13<0.001 p14<0.001 Total 121 (49.0) 159 (64.4) 177 (71.7) 175 (70.9) p < 0.001 p (χ2 test) p1<0.01 p2>0.05 p3<0.01 p1>0.05 p2>0.05 p3>0.05 p<0.001 p1<0.001 p2<0.001 p3<0.001 In the control group, incipient caries rate (with lesion levels D1 and D2) increases from 49.0% pre-intervention up to 64.4% after 6 12 months, 71.7% after 12 months, and 70.9% after 18 months, in both the male and female.