Effect of restoration of children's teeth with mercury amalgam on the prevalence of mercury- and antibiotic-resistant oral bacteria.

The purpose of this study was to determine whether placement of mercury amalgam restorations in children's teeth induces an increase in oral bacteria resistant to mercury, penicillin, ampicillin, erythromycin, or tetracycline. Dental plaque and saliva samples from 16 children without mercury amalgam restorations were screened for bacteria resistant to mercury or to one of the antibiotics prior to, and 1 month after, placement of the amalgam restoration. Following amalgam placement, there was no significant increase in the number of children harboring bacteria resistant to mercury, penicillin, ampicillin, erythromycin, or tetracycline; neither was there an increase in the proportions of such organisms. This study has shown that the presence of mercury restorations in children's teeth has little effect on the prevalence of mercury- or antibiotic-resistant oral bacteria.