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Diffusion fluxes of tritiated water across human enamel membranes

1975; Elsevier BV; Volume: 20; Issue: 5-6 Linguagem: Inglês

10.1016/0003-9969(75)90022-9

1879-1506

Edwin J. Burke, E.C. Moreno,

Material Dynamics and Properties

Isothermal diffusion fluxes of tritiated water across human incisor and canine enamel membranes were measured using a small volume diaphragm cell in the temperature range 13–37 °C. The plano-parallel intact enamel membranes were identified by geometric surface area, thickness, age and sex of donor. The calculated apparent diffusion coefficient values, Da, revealed that significant differences in the water fluxes exist between these two membranes, with the incisors displaying the larger Da values. Diffusional activation energies,Ea, calculated from the Da data obtained at three temperatures indicated an interaction between the diffusing water and the enamel pores, with the larger values observed for the canines. The data are discussed in terms of a parallel pore model in which pore constrictions of the enamel serve as energy barriers to diffusion.