Orabase promotes oral epithelization in a wound healing rat model: An immunohistochemical study

Background: Recent evidence suggests that bone marrow-derived stem cells may have an important role in the natural process of wound healing. The aim of the present study was to examine the effect of orabase paste application on primary wound healing in a palatal rat model. Materials and Methods: A total of 48 six-month-old male Wistar rats weighting 427 to 650 g were included. A mid-crestal incision was made on the maxillary alveolar ridge. A full-thickness flap was raised on either side of the incision and was then repositioned and sutured. Three experimental groups were used: O-study group-orabase, N-negative control group, and I-intact control group. Half of the animals were killed on 7 days and the remaining on 14 days postoperatively. Outcome parameters included epithelial gap; inflammatory infiltration; expression of stem cell markers within the oral epithelium and stromal cells; and physical properties of stromal collagen fibers and myofibroblasts. Investigations were performed at 2 time points (7 and 14 d) during the wound healing process. Results: The epithelial gap closed completely after 7 days in the O group versus 14 days or more in the N group. The inflammatory reaction was relatively low and not significantly different between groups O and N. Orabase upregulated the expression of CK14, CK15, and epithelial SOX2. Connective tissue SOX2, CD34, and α-smooth muscle actin and physical properties of stromal collagen fibers were not influenced by the application of orabase. Conclusions: Orabase promotes epithelial gap closure in a primary wound healing model in rats. The effect is exerted through promotion of epithelial differentiation from stem cells.