Scanning electron and incident light microscopy of giant tubules in red deer dentin.

Incisal and cuspal teeth from red deers 2 1/2-6 1/2 yr of age were used in this study. Incident light microscopy was used for screening of the specimens with respect to presence of orifices and exposures of giant tubules. Scanning electron microscopy (SEM) was used for study of structural details. For SEM the specimens were pretreated with a 1% solution of NaClO for 2 or 20 h. One specimen was in addition exposed to a 35% solution of phosphoric acid for 30 s. Two teeth received no pretreatment. Many incisal/occlusal exposures of giant tubules were more or less blocked by a dense, probably mineralized, substance, whereas others were filled with spherical bodies, probably microorganisms. The walls of the pulpal chambers and root canals revealed an abundance of orifices of giant tubules. They were funnel-shaped with circular or oblong pulpal outlines, the diameters of which in untreated specimens ranged from 15 to 100 microns.