The Determination of Extracellular Fluid Volume in Whole Dental Plaque Using Potassium- or Chloride-selective Micro-electrodes

Abstract

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.

Get full access to this article

View all access options for this article.

References

Carey, C.M. ; Gregory, T.M. ; Rupp, N.W. ; Tatevossian, A. ; and Vogel, G.L. (1986): The Driving Forces in Human Dental Plaque Fluid for Demineralisation and Remineralisation of Enamel Mineral. In: Factors Relating to Demineralisation and Remineralisation of the Teeth, S.A. Leach , Ed., Oxford: IRL Press Ltd., pp. 163-173.

Carey, C.M. ; Tatevossian, A. ; and Vogel, G.L. (1987): The Rapid Determination of Extracellular Potassium Concentrations in Whole Human Dental Plaque and Plaque Fluid, J Dent Res 66:1516-1517.

Cole, M.F. ; Bowden, G.H. ; Korts, D.C. ; and Bowen, W.H. (1978): The Effect of Pyridoxine, Phytate and Invert Sugar on Production of Plaque Acids in situ in the Monkey (M. fascicularis), Caries Res 12:190-201.

Davies, C.W. (1962): Ion Association, Washington : Butter-worth's, p. 41.

Distler, W. and Kroncke, A. (1984): Acids in Single-site Human Resting Plaque, Caries Res 18:160-161.

Distler, W. and Kroncke, A. (1986): Formic Acid in Human Single-site Resting Plaque-Quantitative and Qualitative Aspects, Caries Res 20:1-6.

Distler, W. ; Petschelt, A. ; and Kroncke, A. (1987): Protein Content and Wet Weight of Plaque Microsamples , Caries Res 21:200-203.

Edgar, W.M. and Tatevossian, A. (1971): The Aqueous Phase of Plaque. In: Tooth Enamel II, R.W. Fearnhead and M.V. Stack , Eds., Bristol , UK: Wright, pp. 229-232.

Ferguson, D.B. and Thomas, P.D. (1978): Variability of Calcium and Phosphorus Concentrations in Dental Plaque Collected from Human Anterior Teeth, Arch Oral Biol 23:839-841.

10.

Keyes, P.H. and Jordan, H.V. (1964): Periodontal Lesions in the Syrian Hamster-III , Arch Oral Biol 9:377-400.

11.

McNamara, T.F. ; Friedman, B.K. ; and Roth, P. (1979): Salivary Access as an Ecological Determinant. In: Proceedings, Saliva and Dental Caries, I. Kleinberg , S.A. Ellison , and I.D. Mandel , Eds., Sp. Supp. Microbiol Abstr, pp. 211-225.

12.

Price, W.J. (1979): Spectrochemical Analysis by Atomic Absorption , London: Heydon Press, p. 135.

13.

Rankine, C.A.N. ; Moreno, E.C. ; Vogel, G.L. ; and Mar-Golis, H.G. (1985): Micro-analytical Determination of pH, Calcium, and Phosphate in Plaque Fluid, J Dent Res 64:1275- 1280.

14.

Robrish, S.A. ; Curtis, M.A. ; Sharer, S.A. ; and Bowen, W.H. (1984): The Analysis of Picomole Amounts of L(+)- and D(-)-Lactic Acid in Samples of Dental Plaque Using Bacterial Luciferase, Anal Biochem 136:503-508.

15.

Shaw, L. ; Murray, J.J. ; Burchell, C.K. ; and Best, J.S. (1983): Calcium and Phosphorus Content of Plaque and Saliva in Relation to Dental Caries, Caries Res 17:543-548.

16.

Tatevossian, A. (1981): Kinetics of Calcium-binding and Release in Human Dental Plaque. In: Tooth Surface Interaction and Preventive Dentistry, G. Rølla , T. Sonju , and G. Embery , Eds., London: IRL Press Ltd. , pp. 105-112.

17.

Tatevossian, A. and Gould, C.T. (1976): Methods for Sampling and Analysis of the Aqueous Phase of Human Dental Plaque, Arch Oral Biol 21:313-317.

18.

Van Der Hoeven, J.S. and Franken, H.C.M. (1982): Production of Acids in Rat Dental Plaque with or without Streptococcus mutans, Caries Res 16:375-383.

19.

Vogel, G.L. ; Carey, C.M. ; Chow, L.C. ; and Brown, W.E. (1987): Micro-electrode Techniques for the Analysis of Oral Fluids, J Dent Res 66:1691-1697.

20.

Vogel, G.L. ; Carey, C.M. ; Chow, L.C. ; Gregory, T.M. ; and Brown, W.E. (1988): Micro-analysis of Mineral Saturation within Enamel During Lactic Acid Demineralization, J Dent Res (submitted).