Ultrastructure of regenerating junctional epithelium in the monkey.

It has been established that after gingivectomy the junctional epithelium is reformed from the oral epithelium but there is little information on the regenerative potential of residual junctional epithelium. In this study reformation of the epithelial attachment in the monkey was followed ultrastructurally after surgical removal of all of, or of part of, the original junctional epithelium by internal or external bevel techniques respectively. In both circumstances a new epithelial attachment developed from the adjacent gingival oral epithelium and residual junctional epithelium appeared to persist as small nests of cells adjacent to the cemento-enamel junction. Epithelialization of the gingival wound was rapid, taking place in as little as 5 days after the partial removal of the junctional epithelium by the external bevel technique and by 10 days in wounds in which the junctional epithelium had been completely excised. This difference in the rate of epithelialization seemed to be primarily related to the quantity of coagulum and cell debris present, the greater amount remaining after the internal bevel technique tending to retard epithelial migration and reattachment.