[Incidence of Streptococcus mutans and changes in the concentration of serum immunoglobulins and SIgA in allergic children with caries].

The incidence of Streptococcus mutans in dental plaque and the relationship between dental caries and the levels of serum Igs and IgAS was investigated in allergic children. The relationship between IgAS mean levels and a) cariogenic diet, b) fluoride concentration in consumption water and c) different frequency in brush-washing was also studied. Direct examination of specimens obtained from either dental plaque or caries was performed. Cultures in tryptone soy agar and blood agar base were carried out. Catalase and nitrate reductase tests and biochemical tests for the identification of Streptococcus mutans were also done. Seric Igs and IgAS from saliva secretion were measured by radial immunodiffusion technique. Streptococcus mutans were found in 25/45 samples from allergic children, in 3/16 non allergic, in 25/43 children with caries and 3/18 children without caries. IgM reached higher levels in children with caries. Seric IgA average levels were lower in allergic children and were significantly increased in the non-allergic with caries. Most allergic children with caries showed very low IgAS values. Cariogenic diet, fluoride water ingestion and frequent brush-washing had no effect on IgAS concentration. Allergic children with caries showed low levels of seric IgA and Streptococcus mutans were frequently found in dental plaque. In these patients the specific class IgA response against the potentially cariogenic microorganisms was diminished. Allergic as well as non-allergic children with dental caries showed low IgAS levels suggesting that this may be an important factor in caries development.