Quantitative immunohistochemical analysis of keratins and desmoplakins in human gingiva and peri-implant mucosa.

Quantitative immunohistochemistry was used to compare the distributions of keratins and desmoplakins in human gingiva and peri-implant mucosa (three specimens each). In gingiva, keratin 1 (a marker of cornification) and desmoplakins I & II (markers of desmosomes) stained most heavily in granular strata followed by corneal strata; keratin 13, a marker of non-cornifying stratified squamous cells, stained most heavily in suprabasal strata of oral sulcular epithelium. Keratin 19, a marker for junctional epithelium, stained the basal stratum of oral sulcular epithelium most heavily. In peri-implant mucosa, the patterns of staining were similar, except that staining for desmoplakins I & II was generally significantly reduced compared with gingiva, and junctional epithelium co-expressed keratins 13 and 19. Peri-implant junctional epithelial cells attached to titanium implant abutments were removed by trypsin/EDTA digestion, and also exhibited co-expression of keratins 13 and 19. Inflammatory cell infiltration was associated with reduction of keratin 1 staining in gingiva. The data indicate that the epithelia of gingiva and peri-implant mucosa are not composed of identical cell populations.