Epithelial Reattachment After Gingivectomy in the Rat

Abstract

It is known that an epithelial reattachment occurs a few days after gingivectomy. Depending upon the surgical procedure and the animal species used, different times have been proposed to obtain a complete reattachment. Nevertheless, it is not known whether there is a correlation between the time required and the sequence of morphologic events involved in this process. To investigate this matter, gingivectomies were performed in the maxillary molars of rats. Specimens were taken 1 to 14 days after the operation and processed for light and electron microscopy. The new junctional epithelium appeared at the 5th day, but the earliest signs of reattachment complex formation were evident at the 8th day. Rudimentary hemidesmosomes and lamina lucida appeared in epithelial cells bordering remnants of fibrin. Anchoring filaments that formed between the earliest hemidesmosomes and the subjacent fibrin crossed the lamina lucida. Simultaneously, segments of lamina densa appeared. At the 11th day insertion of tonofilaments into the attachment plaques and insertion of anchoring filaments in the lamina densa were observed. At the 14th day, full development of the reattachment complex was evident.

The junctional epithelium originates from the odontogenic epithelium of an erupted tooth

“…The primary JE is believed to be formed by the fusion of the reduced enamel epithelium with the oral epithelium and gradually replaced by the oral epithelium6132728. Two proteins, odontogenic ameloblast-associated protein and amelotin, which have the potential to create the enamel, have been identified in the JE and observed during the formation and regeneration of the JE171819.…”

Effect of the dental adhesive, 4‐META/MMA‐TBB resin, on adhesion and keratinization of regenerating oral epithelium

“…Experiments using rats have indicated that the oral epithelium proliferates at 2 days post-gingivectomy; the regenerating epithelium then stratifies and keratinizes, with subsequent proliferation of connective tissue. Finally, regeneration of the junctional epithelium leads to completion of gingival regeneration by adhesion to the cemento-enamel junction (CEJ) and enamel surface (10,11).…”

Disruption of periodontal integrity induces expression of apin by epithelial cell rests of Malassez

“…For tooth movement, an orthodontic elastic module (3M Unitek, St Paul, MN, USA) was placed between the first and the second maxillary molars (18). Removal of the gingiva and the JE along the maxillary molars (gingivectomy) was accomplished by scraping the tooth surface and extending 2 mm along the palate with periodontal curettes (SU 15/33, SL 5/6 and KS 1/2; Hi-Friedy, Chicago, IL, USA) (19).…”