An antimicrobial effect from silver-coated toothbrush heads.

Purpose: To examine the antimicrobial effect of silver-coated toothbrush heads in vitro.

Methods: Comparisons were made between 62 silver-coated and 62 non-coated toothbrush heads which were contaminated by different standardized microbial suspensions. The following microorganisms were investigated: Streptococcus oralis, Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Lactobacillus casei and Candida albicans. For cultivation of the microorganisms as well as for the subsequent determination of the colony forming units (CFUs), Columbia blood agar plates or Sabouraud agar were used. The cycle of daily toothbrushing was imitated by rinsing the brushes with 200 ml sterile tap water to reduce the number of microorganisms and the brushes were then placed upright to allow drying overnight. Colony counts were done initially (time 0) and again at 20 hours. The rinsing fluid was also examined in order to determine the decrease of microorganisms due to this step. All experiments were done twice and the means were calculated and statistically evaluated.

Results: There was no significant reduction in CFUs by silver-coated toothbrushes (P > 0.05) for all of the microorganisms tested. On the contrary, the colony counts for S. sanguis (P = 0.02) and C. albicans (P = 0.01) were significantly higher on silver-coated toothbrushes compared to the controls. Silver-coating in the current form did not improve any antimicrobial effects against residual bacteria present on the toothbrush head.