The antibacterial effect of toothpastes on the salivary flora.

Both past and presently available toothpastes contain potential antimicrobial agents which could have a beneficial effect in the prevention of plaque and gingivitis. If these preparations were to be effective clinically, some effect on salivary bacteria would also be expected. This cross-over study measured salivary bacterial counts and the presence or absence of residual antibacterial activity in saliva following tooth brushing with 7 commercially available toothpastes, and moreover, compared their effect with that produced by a chlorhexidine gel. Generally, all toothpaste products produced a reduction in aerobic, anaerobic and streptococcal counts with a hexetidine containing toothpaste producing the largest and longest lasting reduction. In contrast, an enzyme containing toothpaste and an amine fluoride toothpaste, had little effect on bacterial counts. The chlorhexidine gel produced the largest reduction in salivary counts, which was evident for at least 5 h following brushing. Residual antibacterial activity in saliva was only evident immediately following brushing with the hexetidine toothpaste, but for the chlorhexidine gel, was present up to 90 min following brushing. The findings of this study have illustrated the limited antibacterial activity of presently available toothpastes on the salivary flora compared to chlorhexidine, and as such, would tend to question the relative benefit of toothpaste in preventing periodontal disease through an antimicrobial effect.