Use of dentine-fluid protein concentrations to measure pulp capillary reflection coefficients in dogs

Dentine fluid was collected from cavities prepared in teeth before and after intra-arterial administration of histamine. The dentine fluid and plasma were analysed for total protein and the relative concentrations of these two fluids compared. Assuming that dentine fluid protein concentration is similar to that of pulp interstitial fluid around capillaries, reflection coefficients of plasma proteins for pulp capillaries were calculated; after cavity preparation, pulp capillaries were still fairly impermeable to protein, but became less so after histamine administration. There was no difference in protein concentration of samples collected from dentine or directly from the pulp following pulp exposure, indicating that dentine fluid may be used to determine the composition of pulp interstitial fluid.