The uptake of water by freeze-dried human dentine sections.

Ten sections of dentine, cut perpendicular to the dentinal tubules, from human mature non-carious third molars were freeze-dried and then rehydrated by immersion in water. The uptake of water by the sections was determined as a function of time by weighing. Rehydration was complete. On the basis of 3 theoretical models the uptake could be described by a combination of the capillary suction of water into the dentinal tubules and the diffusion of water into the mineralized matrix parallel to the tubules. The calculated diffusion coefficient describing the diffusion of water into the intertubular dentine was 1.74 (+/- 0.42) x 10(-10) m2/s. (mean +/- SEM, n = 10). A further calculation found that 75.2 (+/- 1.5)% of the water is in the tubules and thus 24.8 (+/- 1.5)% is in the mineralized matrix.