Saliva and wound healing.

Wounds in the oral cavity heal faster and with less scarring than wounds in other parts of the body. One of the factors implicated in this phenomenon is the presence of saliva, which promotes the healing of oral wounds in several ways. Saliva creates a humid environment, which improves the survival and functioning of inflammatory cells that are crucial for wound healing. Furthermore, saliva contains a variety of proteins that play a role in the various stages of the intraoral wound healing. Tissue factor, present in salivary exosomes, accelerates the clotting of blood dramatically. The subsequent proliferation of epithelial cells is promoted by growth factors in saliva, especially epidermal growth factor. The importance of secretory leucocyte protease inhibitor is demonstrated by the observation that in the absence of this salivary protein, oral wound healing is considerably delayed. Members of the salivary histatin family promote wound closure in vitro by enhancing cell spreading and cell migration. Cell proliferation is not enhanced by histatin. Cyclization of histatin increased its biological activity approximately 1,000-fold compared to linear histatin. These studies suggest that histatins could potentially be used for the development of new wound healing medications.