Rheological properties of topical fluoride gels.
The rheological properties of several commercial topical fluoride gels were studied. For that purpose, we investigated hysteresis loops under standard conditions, equilibrium values, apparent viscosities as a function of shear rate, rate of thixotropic recovery, and the influence of temperature. The rheological equilibrium values, treated by the Power Law and the Cross Equation, show very important differences. Five gels show pseudoplastic behavior; seven have thixotropic properties. For the risks of fluoride gel toxicity to be lowered, high pseudoplasticity seems most desirable for the first group; for the thixotropic gels, a combination of yield value (very high viscosity at rest), the presence of a static yield value (very fast decrease in viscosity at very low shear rates), and both fast and high thixotropic recovery after destruction seems ideal. Positive and negative, as well as practically no, influence on rheological properties can be noted when the temperature changes.
Plaizier-Vercammen
J A
JA
Lecluse
E
E
Boute
P
P
De Neve
R E
RE
D005460:Fluorides, Topical; D005782:Gels; D012212:Rheology; D014783:Viscosity
D005460:Fluorides, Topical; D005782:Gels