Dolles O K, Bonesvoll P, Gamst O N, Gjermo P
Scand J Dent Res. 1979 Apr;87(2):115-22. doi: 10.1111/j.1600-0722.1979.tb00662.x.
The intention of the present experiment was to study the effects of a possible interaction between fluoride and chlorhexidine when both agents were incorporated in the same vehicle. The amount of fluoride extractable from dentrifrices containing 0.1% NaF and the fluoride ion activity were not reduced by the addition of 2% chlorhexidine digluconate. Less than 50% of the added chlorhexidine was available when the dentifrices were dissolved in deionized water. This was not affected by the presence of fluoride. The in vitro antibacterial activity of the chlorhexidine-containing dentifrices was not reduced by the addition of fluoride. Approximately 40% of the chlorhexidine was retained in the human oral cavity after brushing for 1 min with both the chlorhexidine- and the chlorhexidine/fluoride-containing dentifrice. Thus the binding of chlorhexidine to vehicle ingredients when dissolved in water is probably too weak to affect the retention in the mouth.