The retardation of enamel dissolution rates by adsorbed long-chain ammonium chlorides

Effect of various aliphatic amines on the permeability of bovine dental enamel

Aliphatic amines with chain lengths from C2 to C18 were investigated for their effect on the diffusion of [3H]-sorbitol, [14C]-glycerol, 36Cl- and 86Rb+. Before amine application, enamel was pretreated with a phytate solution. C12-C18 amines reduced the rate of diffusion to values of about 20-30 per cent of the values found before treatment. Amines with chain lengths below C12 were less effective. The presence of an unsaturated carbon-carbon bond (C18:1) seems to promote the absorbance of the amine to enamel.

Effect of phytate and hexadecylamine on the permeability of bovine dental enamel

The effect of hexadecylamine on the permeability of bovine dental enamel was investigated using a radiochemical diffusion technique. Treatment with an aqueous solution of hexadecylamine reduced the permeability of the enamel by about 20 per cent. Pre-treatment of the enamel with an aqueous solution of phytate followed by hexadecylamine yielded a reduction in permeability of approximately 70 per cent. The observed effects were similar for ionic (86Rb+ and 36Cl-) and non-ionic [( 3H]-sorbitol and [14C]-glycerol) compounds. The strong permeability-reducing effect of the combined phytate-amine treatment may also be anticariogenic.

EDTA enhancement of strontium uptake by intact human enamel

The aim of this research was to study the effect of EDTA on the strontium uptake by intact tooth enamel. EDTA did not significantly affect the strontium uptake in an acid medium of pH 4.5. However, it caused a sharp rise in strontium uptake at pH 6.0. At such a pH, the stability constants of the Ca-EDTA complex are approaching a maximal value, and as a result of it a significant dissolution of the surface enamel, accompanied by a highly effective increase of the contact area for strontium uptake, is taking place. In all the experiments, treatment with strontium solution resulted in a decrease of the solubility and dissolution rate of enamel in an acidic environment. The resistance of enamel to acid attack was proportional to the quantity of absorbed strontium, reaching maximal values after treatment with strontium solutions in 10(-2) M EDTA at pH 6.0.

The caries-preventive effect of amine fluorides and inorganic fluorides in a mouthrinse or dentifrice after 30 months of use

The study groups using a dentifrice and mouthrinse both containing fluorides, a dentifrice containing stannous fluoride and a mouthrinse containing sodium fluoride, or a mouthrinse containing sodium fluoride with a placebo dentifrice had a 20.7% to 29.0% lower DMF increment than the control group after 30 months. These differences were significant. The study groups using a dentifrice containing amine fluorides and a placebo mouthrinse, a mouthrinse containing amine fluorides and a placebo dentifrice, or a dentifrice containing stannous fluoride and a placebo mouthrinse had a 13.6% to 22.4% lower DMF increment than the control group. These differences were not statistically significant. There was no significant difference in effectiveness against caries between the use of the organic or inorganic fluoride products.

Adsorption of Streptococcus mutans on chemically treated hydroxyapatite

Adsorption of Streptococcus mutans on hydroxyapatite and chemically treated hydroxyapatite was studied. Zeta potentials of the surfaces were measured. Chemically treated hydroxyapatite gave higher zeta potentials and lower S mutans adsorption.

Structure-activity studies on inhibition of Streptococcus mutans by long-chain aliphatic diamines

A series of long-chain aliphatic diamines, R1R2N(CH2)mNR3-CnH2n+1' was tested for in vitro inhibition of Streptococcus mutans. In general, high activity was found for all analogs with alkyl chains containing 14 to 18 carbons. The nature of the substituents on the remainder of the alkylenediamine were of secondary importance. N-hydroxyethyl substituents tend to decrease activity. Good correlations of activity with quadratic functions of diamine critical micelle concentrations were obtained.

Precipitate-free, dilute aqueous solutions of stannous fluoride for topical application. I. Simple and mixed mediums

Sodium fluoride, glycerol, and tartaric acid maintained dilute aqueous solutions of stannous fluoride precipitate-free under the conditions of this experiment. In the absence of any precipitate, a "loss" of either stannous ions or both stannous and fluoride ions, indicates the possibility of the formation of water-soluble complexes in these solutions.