We examined the relationship between serum glucose value and caries incidence in 88 children (61 boys and 27 girls) in the deciduous dentition period with an average age of 3 years and 11 months (2 to 6 years old), and reached the following conclusions.

1. While the group who had a “decayed teeth rate” (number of untreated carious teeth/(number of erupted teeth+ number of missing teeth) × 100%) of 50% or lower had an average serum glucose value of 101.5 mg/dL, the average serum glucose value of the group whose decayed teeth rate exceeded 50% was higher at 110.4 mg/dL. However, we did not observe a significant difference between the two groups.

2. While the average serum glucose value for the group with zero C3 teeth was 92.8 mg/dL, the average serum glucose value for the group with one to four C3 teeth was 108.0 mg/dL, which was significantly higher than the former (p ＜ 0.05 : t-test). The average serum glucose value for the group with five or more C3 teeth was 112.5 mg/dL, which was even more significantly higher than the group with zero C3 teeth (p ＜ 0.01 : t-test).

Based on these results, the serum glucose values of children with severe caries tended to be higher than those of children with mild caries, indicating the possibility that severe caries is associated with carbohydrate metabolism.