It is important to screen infants with a high risk of dental caries and give them appropriate oral health instruction. In this study, relationships between the dental caries status and their life style were investigated longitudinally in infants from 18 to 24 months old. The subjects were 1641 children who participated in dental health screening both at 18 months and 24 months of age. Oral examinations, caries activity tests (the Cariostat) and dental health questionnaires were used out in each screening. The subjects were divided into three groups according to their status of dental caries at 18 months of age; the caries-free group (Group 1), the initial carious group (Group 2) and the dental carious group (Group 3). The results are as follow:
1. Group 2 showed a worse caries status at 24 months of age than Group 1.
2. According to the Cariostat test, Group 2 presented lower caries activity than Group 3.
3. Group 2 reported different responses to life style questions compared with Group 1 and 3. These results suggested that initial caries could be utilized as one of the screening methods for infants.