Keratinizing potential of sulcular epithelium.

It has been shown that the connective tissue base determines the epithelial surface characteristics. Although there is no apparent difference between the connective tissues underlying the subcular and the surface gingival epithelium, the sulcular epithelium is not keratinized as is the gingival surface. The influence of the sulcular environment in determination of keratinization was explored in three adult Rhesus monkeys. Twenty-four intrasulcular mucoperiosteal flaps were elevated beyond the buccal mucogingival border, were turned inside out and sutured to leave the sulcular epithelium exposed on the surface. Short term speciments (1 hour to 7 days) were obtained from one monkey which received H3 thymidine 1 hour prior to sacrifice. Biopsies were obtained from the other two monkeys covering intervals of 1 week to 2 months. The findings indicate that the sulcular epithelium has potential for keratinization. The contact to the tooth appears to determine the lack of keratinization of the sulcular epithelium.