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

Background and Objective: The 4‐META/MMA‐TBB [4‐(2‐methacryloxyethyl)trimellitic anhydride/methyl methacrylate‐tributylborane] resin is widely used as a dental adhesive. It has also been applied in the dressing of gingival wound surfaces following periodontal surgery. However, its effect on the regeneration and/or cell attachment of the oral epithelium remains to be clarified. To evaluate the effect of the resin applied as a wound dressing, we investigated expression of laminin 5, integrin β4 and cytokeratin 14 in regenerating oral epithelium treated with this resin following gingivectomy from the viewpoint of cell attachment and differentiation. Material and Methods: The resin was applied to the entire wound surface in rats after gingival surgery, and regenerating epithelium was examined immediately and at 1, 3, 5, 7 and 14 days later. The resin was removed 2 weeks after application in some animals and tissue further examined at 1, 3, 5 and 7 days later. Results: Regenerating epithelium under the resin was not keratinized, but became keratinized immediately after removal of the resin. Laminin 5 and integrin β4 were immunolocalized in the basal lamina, the internal basal lamina, in marginal cells of the regenerating epithelium and at the resin–regenerating epithelium interface. Cytokeratin 14 localized in the regenerating epithelium underneath the resin, as well as in healthy and regenerated junctional epithelial cells. Conclusion: These results suggest that this resin covers the wound surface and that the regenerating epithelium biologically adheres to the resin during the initial process of its regeneration.