Scanning electron microscopic studies on demineralized guinea pig dentin

– Sound, demineralized adult guinea pig dentin was observed by means of the scanning electron microscope. The dentinal tubules were fairly regular, some of them containing odontoblastic processes (Tomes fibers). These fibers were smooth surfaced, branching and much smaller than the surrounding tubules. Their small diameters were probably caused by the preparation procedures. The inner tubular walls were rough, probbly because of interlacing collagen fibrils. The peritubular dentin was relatively compact and composed of a considerable amount of cross‐striated fibrils. Similar fibrils were found in the intertubular zones where they were arranged in fiber‐bundles giving the intertubular zones a honeycombed or spongelike appearance. Such a distinct honeycombed appearance was not found in transmission electron microscope studies of dentin. This discrepancy is possibly due to differences in tissue preparation. The relatively poor development of peritubular dentin compared with intertubular dentin is in agreement with other studies in animals with continued tooth growth.