Interodontoblastic collagen (von Korff fibers) and circumpulpal dentin formation: An Ultrathin serial section study in the cat

Abstract

The collagenous fibers of von Korff pass from the dentin matrix between the odontoblasts into the dental pulp. Although collagen fibrils are known to be present between odontoblasts, the existence of von Korff fibers has remained controversial. This may be because their continuity between the dentin matrix and the pulp has not been demonstrated ultrastructurally. In this study we have examined the odontoblast layer in the middle to apical regions of perfusion-fixed permanent canine teeth of cats by using transmission electron microscopy. Ultrathin sections of demineralized specimens revealed frequent bundles of collagen fibrils 1) entering the odontoblast layer from the predentin, 2) present between odontoblast cell bodies, and 3) passing from between the odontoblasts into the pulp. The question of continuity of these bundles from the predentin, across the odontoblast layer into the pulp was examined in ultrathin serial sections. Unbroken continuity of a collagen bundle from the predentin between the odontoblasts into the pulp was established in a reconstruction of one series of 22 serial sections and was very strongly suggested by a number of other series in which the numbers of available sections restricted their full visibility. This investigation has shown, therefore, that classical von Korff fibers are present and that these fibers are present in fully erupted teeth with closed apices, i.e., at a time when secondary circumpulpal dentinogenesis is in progress. The findings call for a reexamination of the question of von Korff fibers during mantle dentinogenesis and primary circumpulpal dentinogenesis. Resolution of their existence at the earlier stages of dentinogenesis should be possible by using the ultrathin serial-sectioning technique.

Light-microscopical investigation of the distribution of extracellular matrix molecules and calcifications in human dental pulps of various ages

“…The interodontoblastic spaces are very narrow, and the high density of intercellular junctions between odontoblasts make it difficult to identify the extracellular matrix in this layer. Scanning and transmission electron microscopical studies have revealed the presence of interodontoblastic collagen fibers, which cross the distal junctional complex of the odontoblasts and penetrate into and across the predentin (Bishop et al 1991;Salomon et al 1991;Tabata et al 1994). By using a confocal laser scanning microscope, we have observed the three-dimensional distribution of collagen type VI in the pulp of human teeth, especially in the odontoblast layer.…”

Location, arrangement and possible function of interodontoblastic collagen fibres in association with calcium hydroxide-induced hard tissue bridges

“…1991). During secondary physiologic dentine formation, the pattern of interodontoblastic collagen fibre occurrence is irregular in cats (Bishop et al . 1991).…”

“…Recent transmission electron microscopy and scanning electron microscopic studies show the existence of interodontoblastic collagen fibres in human dentine (Sogaard‐Pedersen et al . 1990), in the root of cat dentine (Bishop et al . 1991) and in mechanically exposed monkey dental pulp (Kitasako et al .…”

The mineralization of mantle dentine and of circumpulpal dentine in the rat: an ultrastructural and element-analytical study

“…On the other hand, recent data from rat and cat molars suggest that the von Korff fibres originate in the pulp, pass through the odontoblast layer and the predentine and can be traced into the circumpulpal dentine of the crown (Bishop et al 1991) and the root (Salomon et al 1991).…”