Expression of Integrin alpha-3 and beta-4 subunits on the process of peri-implant epithelium formation

Integrin, a component of the hemidesmosome, plays a role for epithelial cell migration and adhesion. This study investigated the process of peri-implant epithelium (PIE) formation after implantation, and compared it to the process of oral mucosa healing after tooth extraction. At the healing site of extraction socket without implant, the original junctional epithelium (JE) had disappeared at week 2, and the oral epithelium (OE) with integrin-α3 positive basal cells extending from the sides of the wound, then joined in the middle of the extraction socket. On the other hand in implant group, newly formed epithelium with integrin-α3 positive cells from the OE extended apically 1 week after implantation. After 3 weeks, basal cells of the new epithelium consisted of those with integrin-α3 positive but β4 negative. Finally, after 4 weeks, integrin-β4 was expressed at the implant-PIE interface. These findings suggest that integrin α3β1 plays a role in cell migration during PIE formation from OE. Furthermore, after the completion of PIE constitution, integrin α6β4 contributes to the attachment to titanium.