Ultrastructural and immunohistochemical similarities in the attachment of human oral epithelium to the tooth in vivo and to an inert substrate in an explant culture.

Abstract

Laminin and type IV collagen were localized in the mucosal and vascular basement membranes in sections of human deciduous and permanent teeth with the junctional epithelium still in situ. These essential basement membrane constituents were also demonstrable at the epitheliumconnective tissue interface under the stationary and migrating epithelium (epibolus) of cultured palatal mucosa. The contact of the epithelium with the cementum or enamel in vivo and with a Millipore® filter in vitro, instead of connective tissue, influenced the chemical composition of the epithelial attachment apparatus. Laminin was found both in the epithelial attachment on the tooth and within the Millipore® filter under the migrating epithelium. Type IV collagen was not, however, localized in the attachment apparatus on the tooth nor in the epithelium‐filter interface despite the presence of a unit attachment apparatus with basal lamina, hemidesmosomes, and anchoring filaments along the filter.These findings support the idea of the tooth as an inert substrate for epithelial cells and provide further grounds for the application of the described in vitro model to the study of the chemical constituents of the epithelial attachment.