Aims: This study aimed to evaluate the effect of lead (Pb) on growth of bacterial species related to dental diseases in vitro.
Methods and results: The effects of lead acetate on representative species of the oral flora were examined at 0.1-10 mmol l(-1) and compared with the effect of silver nitrate and ferrous sulfate. The minimal inhibitory concentration of lead acetate was between 0.15 and 5 mmol l(-1) for the bacterial strains tested. The minimal bactericidal concentration of lead acetate for most oral species was detected in the range of 5-10 mmol l(-1). Silver nitrate at a concentration of 1.25 mmol l(-1) was sufficient to exhibit antibacterial activity against almost all bacteria tested. Ferrous sulfate had the lowest effect.
Conclusions: The study indicated a general antimicrobial effect of lead on oral bacterial species in the range of 0.15-10 mmol l(-1). The toxicity of silver nitrate was the highest, whereas that of ferrous sulfate was the lowest. Gram-positive species had a tendency to be less susceptible for metals than Gram-negatives.
Significance and impact of the study: The study shows that it is possible that microbiological changes may occur in the dental plaque in children because of toxic exposure of environmental lead.
© 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.