Journal of Dental Research, Vol 67, 866-869, Copyright © 1988 by International & American Associations for Dental Research Online Journals

ARTICLES

The determination of extracellular fluid volume in whole dental plaque using potassium- or chloride-selective micro-electrodes

C. M. Carey, G. L. Vogel and L. C. Chow
Paffenbarger Research Center, American Dental Association Health Foundation, National Bureau of Standards, Gaithersburg, Maryland 20899.

This paper describes a procedure for the determination of the volume of water available for diffusion in whole plaque samples collected from single sites. In this procedure, known micro volumes of H2O were added to single-site plaque samples with calibrated nanoliter pipettes and the potassium or chloride concentration at each dilution measured with ion-selective micro-electrodes. By plotting the inverse of the concentration versus the volume of H2O added, one can determine the original volume of plaque fluid available for diffusion. Volumes determined in simultaneous measurements performed with chloride and potassium micro-electrodes were statistically indistinguishable. From the observed constancy in the initial potassium concentration in rat and human plaque fluid, a simplified macro method is suggested which allows for estimation of the extracellular fluid volume within 20% error in plaque samples.

This article has been cited by other articles:

				C.M. Carey, G.L. Vogel, and L.C. Chow Permselectivity of Sound and Carious Human Dental Enamel as Measured by Membrane Potential Journal of Dental Research, December 1, 1991; 70(12): 1479 - 1485. [Abstract] [PDF]