Abstract
Immunoglobulin A (IgA) antibodies reacting with Streptococcus mutans were analyzed in mouth rinses from 38 adults. Antibody activity was determined by an enzyme-linked immunosorbent assay. The IgA antibody activity varied considerably in samples from different individuals. Of the 38 subjects, 12 volunteered in an implantation experiment and were challenged with streptomycin-resistant S. mutans. The results indicated that individuals with relatively high IgA antibody activity in mouth rinses more rapidly eliminated the challenge strain than subjects with low IgA antibody activity.