Effect of chlorhexidine mouthrinses on concentration of IgA in expectorates.

Secretory IgA is usually found in high concentrations in the mucin layer of the oral mucosa. Chlorhexidine (CH) has been shown to precipitate mucin and may thus reduce the amount of IgA available in the oral cavity. Two human experiments were performed using single radial immunodiffusion (SRID) for quantitation of IgA in expectorates after mouthrinses. CH mouthrinses eluted significantly more IgA from the oral cavity than did water. However, regular CH rinses for 1 week did not seem to reduce significantly the amount of IgA the could be extracted by water of CH. The present study did not support the suggestion that CH mouthrinses may reduce the IgA dependent defence mechanisms in the oral cavity.