Serum IgG level against Streptococcus mutans in subjects with caries experience.

Serum IgG level against Streptococcus mutans serotype c was studied in 33 subjects, in relation to dental caries, oral hygiene and age. The activity of the serum IgG against the sonicated antigens of the bacterium was evaluated by micro-ELISA. The serum IgG titer to S. mutans was significantly higher in the subjects with no detectable carious lesions than in the subjects with active caries (p less than 0.05). However, there was no clear difference between the serum IgG antibody to S. mutans and the DMF index. The serum IgG antibodies to S. mutans were associated with the level of oral hygiene but not with age.