Erupted teeth with attached gingival tissue were obtained from 15 patients ranging in age from 4 to 26 years. After preliminary glutaraldehyde fixation, the area to be studied was excised with a high speed dental drill. The tissue was decalcified in Versene, subdivided into smaller blocks and post-fixed in 2% buffered osmic acid fixative. Epon embedded sections were stained with uranyl acetate and lead citrate prior to being examined in the electron microscope.

The results indicate that (1) an attachment is present between the epithelial cuff and enamel or cementum, (2) the attachment apparatus of epithelium to tooth structure consists of hemidesmosomes and a cementing layer resembling the basement lamina of various epithelium-connective tissue junctions, (3) the attachment may be to two types of cuticle of undetermined origin, or directly to the tooth, and (4) apical to the epithelial attachment the gingiva is connected to cementum by parallel bundles of collagen fibrils which extend from the gingiva into the cementum. The cementum itself consists of parallel collagen fibrils the periodicity of which is in register between adjacent fibrils. The fibrils are embedded in a rather sparse, granular matrix.