The movement of radioactive molecules across dentine in vivo in the dog

Using a technique for measuring the movement of circulating molecules across the odontoblast-dentinal complex, the movement of water and alpha-aminoisobutyric acid through dentine and into a flow cell prepared on the tooth is described. The movement of water depended on dentine thickness, and varied from 0.40 microliter/min per cm2 in a flow cell overlying an average thickness of 0.74 mm of dentine, to 1.23 microliter/min per cm2 in a flow cell with a dentinal floor of 0.40 mm average thickness. The data suggest that alpha-aminoisobutyric-acid concentrations were lower in dentinal fluid than in blood plasma.