Interactions of perfluoroalkyl surfactants to teeth in vitro and in vivo

Abstract

Four perfluoroalkyl surfactants were evaluated for their effects on the adsorption of bacteria onto teeth in vitro and in vivo effects on caries and gingivitis. Perfluoroalkyl sodium sulfonate (FAS) and perfluoroalkyl amino acid (FAA) showed minimum inhibition on the adsorption of S. mutans and A. viscosus to saliva-coated hydroxyapatite (HA) beads or disks. 1,1,1-Trifluoro-2,4-pentadecadione (TFPD) was ineffective against the adsorption of S. mutans to coated HA disks and was inactive against caries in rats. TFPD was effective in inhibiting the adsorption of A. viscosus to saliva-coated HA and also significantly ( P=0.05) reduced gingivitis formation in primates when applied topically. Perfluorosulfoamido alkyl ester of phosphorous acid (PSAEP) was the most effective in inhibiting the bacterial adsorption to the coated HA. ESCA studies indicated that PSAEP adsorbed to the saliva-coated HA disks. The adsorption parameters derived from an isotherm on the coated disks were K=6.66×10 2 l M −1 and N=14.0×10 −8 M m −2. At saturation concentration on the coated HA disks, PSAEP covered 18% of the available surface which gave 66% inhibition of the bacterial adsorption. PSAEP applied topically significantly ( P=0.05) reduced dental caries induced by S. mutans. Collectively, the results of these studies indicated that it was possible to reduce dental caries and gingivitis via treatment of teeth with specific perfluorosurfactants.