Localization and synthesis of type III collagen and fibronectin in human reparative dentine

Abstract

The injury of dental pulp tissue, following caries, is accompanied by the deposit of a typical hard scar tissue known as reparative dentine which should be regarded as the mineralization of a new organic matrix. Highly purified antibodies were used in combination with immunoperoxidase or immunogold technique at the ultrastructural level to reveal the distribution and synthesis of types I and III collagen and fibronectin elaborated by typical matrix-forming cells in the new tissue. Specific immunoperoxidase labelling, on demineralized teeth, clearly demonstrated that type I collagen represents the main type of collagen (88%). It is associated with bundles of fine striated fibrils of type III collagen and in close vicinity with fibronectin and constituted, at least, the new organic matrix of reparative dentine. Immunogold staining gave precise localization mainly over Golgi apparatus for the 3 components, thus suggesting that the cells concerned should not be considered as new odontoblasts but rather as pulpal cells in the process of differentiation participating in the formation of new dentine. Moreover, these events are very similar to those observed during wound healing in other tissues.

A Quantitative Light Microscopic Study of the Odontoblast and Subodontoblastic Reactions to Active and Arrested Enamel Caries without Cavitation

“…Those findings are in accordance with clinical observations [Massler, 1967;Nyvad and Fejerskov, 1987;Schüpbach et al, 1990] and after lesion arrest of deep carious lesions following stepwise excavation [Bjørndal et al, in press]. The second methodological problem has been technical difficulties in obtaining thin undemineralized tooth sections [Yoshida and Massler, 1964;Brännström and Lind, 1965;Kuwabara and Massler, 1966;Langeland, 1987;Magloire et al, 1988;Kobayashi et al, 1996]. In this study we applied a method to produce undemineralized tissue sections for cellular examinations, which previous studies have proved to be appropriate for examination of teeth [Donath, 1987;.…”

“…Due to technical difficulties it has not been possible to examine pulp-dentinal reactions to caries in relation to the undemineralized features of the overlying hard tissue lesion [Yoshida and Massler, 1964;Brännström and Lind, 1965;Kuwabara and Massler, 1966;Langeland, 1987;Magloire et al, 1988;Kobayashi et al, 1996]. It is well known that human enamel is a microporous solid [Bergman, 1963;Dibdin, 1993] allowing transport of stimuli from the external environment to the dentine/pulp complex.…”

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

“…Our findings indicate that type V and VI collagen are important components of human dental pulp and that they might contribute to the function of cellular elements. These data suggest a significant, but as yet unknown, role of the matrix proteins, especially collagens V and VI, in the normal function and perhaps during the formation of reparative dentin (Magloire et al 1988;Higashi and Okamoto 1996) and other calcified structures.…”

An in vitro Model of Human Dental Pulp Repair

“…This long-term maintenanice of the odontoblast phenotype could be correlated with the presence of dentin tissue (Heywood and Appleton, 1984) or dentin matrix components (Tziafas et (l., 1990(Tziafas et (l., , 1992BegueKirn et al, 1992BegueKirn et al, , 1994Smith et al, 1994) released during the probable demineralization process produced by ascorbic acid present in the culture medium. Indeed, ascorbic acid was shown to be a weak demineralizing agent for histological procedures (Dietrich and Fontaine, 1975) and was sucessfully used on tooth slices for electron immunocytochemistry (Magloire et al, 1988).…”