Histological evaluation of rabbit gingival wound healing transplanted with human amniotic membrane.

Human amniotic membrane has been used as a material to accelerate wound healing and reconstruct damaged organs. The aim of the present study was to assess histologically human amniotic membrane transplantation on rabbit's gingival wound. Three- to 4-month-old male rabbits were divided into 2 groups, i.e., control (group I) and amniotic membrane-transplanted animals (group II). Buccal gingival wounds were created by a punch-biopsy instrument and covered by a 5-layered human amniotic membrane for group II or left uncovered for group I. Gingival biopsies were taken at days 1, 3, 5, 7 and 10, processed for paraffin sections and stained with haematoxylin-eosin or von Gieson. Thickness of epithelial layer, the number of polymorphonuclear cells (PMN), fibroblasts and new blood vessels as well as density of collagen fibres were assessed. The results showed that the number of fibroblasts and new blood vessels, but not PMN, from group II was higher than that from group I (P < 0.05). Similarly, the epithelial thickness and density of collagen fibres from group II were significantly higher than those from group I (P < 0.05). The results of the present study indicate that amniotic membrane transplantation may induce rapid epithelialization and both granulation tissue and collagen formation but suppress inflammation, suggesting that amniotic membrane transplantation may promote rapid gingival wound healing in rabbits compared to secondary healing.