As for incipient caries, the results showed in table 3.17 shows that: In the control group, incipient caries rate increases from 49.0% pre - intervention up to 64.4% after 6 months, 71.7% after 12 months, and 70.9% after 18 months. Meanwhile, the incipient caries rate of the intervention group also slightly increases from 65.0% pre-intervention up to 71.1% after 6 months, then decreases down to 42.6% after 12 months, and 39.0% after 18 months of intervention.