Determination of the functional space for fluid movement in the rat dentinal tubules using fluorescent microsphere

The dentinal tubules in the inner third of the rat coronal dentine may have a space less than 0.1 μm through which dentinal fluid can move, despite outward tapering of the dentinal tubules. Retrograde tapering may increase the pressure in the inner third of the dentine layer, and this elevated pressure may contribute to mechanical deformation of the content in the dentinal tubules.