Crevicular IgG antibodies and recovery of Streptococcus mutans implanted by mouthrinsing

After challenge with a streptomycin-resistant strain of Streptococcus mutans (S. mutans), a tendency to higher recovery of S. mutans was found in gingival crevicular fluid (GCF) from surfaces with a low IgG antibody activity against S. mutans than in GCF from surfaces with a high antibody activity. This suggests that antibodies in GCF may interfere with the establishment of S. mutans on gingival tooth surfaces. In GCF collected from some sites, considerably higher IgG antibody activity was observed than in homologous serum, indicating that part of the IgG response to S. mutans was locally derived.