Caries prevalence in children below the age of 6 year-old in developed country was 1-12% and in developing country was 70% while in Indonesia was 90%. Mother’s knowledge regarding oral health is expected to reduce caries experience of preschool children. The aim of this study is to find out the relationship between Mother’s knowledge and the caries experience of children. A cross sectional study was performed at kindergartens in Padang city. The sample was 64 pairs of mother and children (3 – 6 year of age) which was selected by proportionate stratified random sampling. Mother’s knowledge level was obtained through a questionnaire of oral health. Caries experience was assessed using the def-t index. The obtained data was analyzed statistically using T-test. On average, def-t index of the 64 children with caries experience was 6.1. More than half of mother (57.8%) was senior high school graduate. Mother who was junior high school graduate had their children experiencing caries with 9.86 of def-t index. Most of the mother had low level of knowledge (73.4%). Mother with low level of knowledge had their children experiencing caries with 6.13 of def-t index while mother with high level of knowledge had their children experiencing caries with 6.24 of def-t index. The t-test result showed p=0.93 and p value > 0.05. There was no significant association between caries experience of children and mother with low or high level of knowledge. The mother’s level of knowledge regarding children’s oral health did not affect the number of children’s decayed teeth. There was no significant association between mothers’ knowledge and caries experience of preschool children.

Keywords : Caries Experience, Mother’s Knowledge, Deft Index.