Effects of Distance from the Pulp and Thickness on the Hydraulic Conductance of Human Radicular Dentin

Abstract

The purposes of this study were: (1) to measure the effect of distance from the pulp on the hydraulic conductance of human radicular dentin ; (2) to determine the influence of dentin thickness on the rates of fluid flow; and (3) to attempt to correlate dentinal tubule densities and diameters with root dentin hydraulic conductance. Dentin slabs prepared from extracted, unerupted, human third molar teeth were placed in a split-chamber device to permit quantitation of fluid filtration rate (hydraulic conductance). In the SEM portion of the study, dentinal tubule numbers and diameters were recorded. The results indicated that radicular dentin hydraulic conductance decreased with distance from the pulp and with increasing dentin thickness. Tubule density and diameter correlated well with the measured hydraulic conductances. The relatively low hydraulic conductance of outer root dentin makes it a significant barrier to fluid movement across root structure.

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References

Anderson, D.J. and Ronning, G.A. (1962): Osmotic Excitants of Pain in Human Dentine, Arch Oral Biol 7:513-523.

Anderson, D.J. ; Matthews, B. ; and Gorretta, C. (1967): Fluid Flow Through Human Dentine, Arch Oral Biol 12:209-216.

Bergenholtz, G. (1977): Effect of Bacterial Products on Inflammatory Reactions in the Dental Pulp, Scand J Dent Res 85:122-129.

Bhaskar, S.N. (1976): Orban's Oral Histology and Embryology, St. Louis, MO: The C.V. Mosby Company, pp. 107-108.

Brannstrom, M. ; Linden, L.A. ; and Astrom, A. (1967): The Hydrodynamics of the Dental Tubule and of Pulp Fluid, Caries Res 1:310-317.

Carrigan, P.J. ; Morse, D.R. ; Furst, M.L. ; and Sinai, I.H. (1984): A Scanning Electron Microscopic Evaluation of Human Dentinal Tubules According to Age and Location, J Endod 10 :359-363.

Garberoglio, R. and Brannstrom, M. (1976): Scanning Electron Microscopic Investigation of Human Dentinal Tubules, Arch Oral Biol 21:355-362.

Marshall, F.J. ; Massler, M. ; and Dute, H.L. (1960): Effects of Endodontic Treatments on Permeability of Root Dentine, Oral Surg Oral Med Oral Pathol 13:208-223.

Martin, H. ; Lasala, A. ; and Michanowicz, A. (1968): Permeability of the Apical Third of the Root to Drugs Used in Endodontic Therapy: An in vitro Study, J Oral Therap 4:451-455.

10.

Merchant, M.J. ; Livingston, M.J. ; and Pashley, D.H. (1977): Dentin Permeation: Comparison of Diffusion with Filtration, J Dent Res 56:1161-1164.

11.

Michelich, V. ; Pashley, D.H. ; and Whitford, G.M. (1978): Dentin Permeability: A Comparison of Functional versus Anatomical Tubular Radii, J Dent Res 57:1019-1024.

12.

Outhwaite, W.C. ; Livingston, M.J. ; and Pashley, D.H. (1976): Effects of Changes in Surface Area, Thickness, Temperature and Post-Extraction Time on Human Dentine Permeability , Arch Oral Biol 21:599-603.

13.

Pashley, D.H. (1979): The Influence of Dentin Permeability and Pulpal Blood Flow on Pulpal Solute Concentration, J Endod 5 :355-361.

14.

Pashley, D.H. and Galloway, S.E. (1985): The Effects of Oxalate Treatment on the Smear Layer of Ground Surfaces of Human Dentine, Arch Oral Biol 30:731-737.

15.

Pashley, D.H. ; Kalathoor, S. ; and Burnham, D. (1986): The Effects of Calcium Hydroxide on Dentin Permeability , J Dent Res 65:417-420.

16.

Pashley, D.H. and Livingston, M.J. (1978): Effect of Molecular Size on Permeability Coefficients in Human Dentine, Arch Oral Biol 23:391-395.

17.

Pashley, D.H. ; Livingston, M.J. ; and Greenhill, J.D. (1978a): Regional Resistances to Fluid Flow in Human Dentine in vitro, Arch Oral Biol 23:807-810.

18.

Pashley, D.H. ; Livingston, M.J. ; and Outhwaite, W.C. (1977): Rate of Permeation of Isotopes Through Human Dentin, in vitro, J Dent Res 56:83-88.

19.

Pashley, D.H. ; Livingston, M.J. ; Reeder, W.O. ; and Horner, J.A. (1978b): Effects of the Degree of Tubule Occlusion on the Permeability of Human Dentine in vitro, Arch Oral Biol 23:1127-1133.

20.

Pashley, D.H. ; Michelich, V. ; and Kehl, M.S. (1981a): Dentin Permeability: Effects of Smear Layer Removal , J Prosthet Dent 46:531-537.

21.

Pashley, D.H. ; Nelson, R. ; and Williams, E.C. (1981b): Dentin Hydraulic Conductance: Changes Produced by Red Blood Cells, J Dent Res 60:1797-1802.

22.

Pashley, D.H. ; Stewart, F.P. ; and Galloway, S.E. (1984): Effects of Air-drying in vitro on Human Dentine Permeability, Arch Oral Biol 29:379-383.

23.

Pashley, D.H. ; Thompson, S.M. ; and Stewart, F.P. (1983): Dentin Permeability: Effects of Temperature on Hydraulic Conductance, J Dent Res 62:956-959.

24.

Reeder, O.W. ; Walton, R.E. ; Livingston, M.J. ; and Pashley, D.H. (1978): Dentin Permeability: Determinants of Hydraulic Conductance, J Dent Res 57:187-193.

25.

Sorenson, F.M. and Gatewood, D.C. (1966): Formalin Penetration of Extracted Teeth, J Dent Res 45:1413-1418.