Caries risk-graded intervention for preschool children is needed as different child has different risk to suffer from caries.~Cariogram and Cariostat are two different and common caries risk assessment tools. Cariogram is a complicated but economical computer program which is more sensitive for caries risk assessment. Cariostat is a biological reagents with high specificity but it may be expensive to use for large numbers of children.~The experimental group will be divided into two subgroups, one use Cariogram and the other use Cariostat to assess the risk. Based on the results of the assessment, children with low risk of caries will get routine prevention including twice fluorinated foams each year and hygiene. Children with middle or high risk of caries will receive twice fluorinated varnish each year and professional caries treatment in addition to routine prevention.Routine prevention will be taken for the control group with both Cariogram and Cariostat assessment.~Follow-up will arrange one and two years after baseline recruitment. All participants will receive oral health-related questionnaires at baseline and follow-up.~The prevalence of caries in the experimental group and the control group should be evaluated, and the cost-effectiveness evaluation will be conducted.
Cariogram and Cariostat will be used to assess the risk of caries in kindergarten children aged 3 years. Routine preventive measures will be taken for children at low risk of caries, and intensive intervention measures will be taken for children at medium and high risk. Routine measures will be taken for the control group. After one and two year, the prevalence of caries in the experimental group and the control group should be evaluated, and the cost-effectiveness evaluation will be conducted.