After completing the surgical incision of El, the gingival flap is turned over. The types of gingival flaps include both full-thickness flaps and semi-thickness flaps. The soft tissue flap that is turned up in most cases is the mucoperiosteal flap, also known as the full-thickness flap. A blunt separation is performed with a periosteal separator and the periosteum is turned up along the alveolar bone along with the gingival flap to expose the lesion area. In some cases of membrane gingival surgery, or where the alveolar bone plate is very thin or has an “open bone window”, a partial thickness flap is used to protect the alveolar ridge from excessive resorption due to exposure, i.e., the gingival flap includes only the surface epithelium and a portion of the underlying connective tissue, while the deep connective tissue remains over the alveolar bone along with the periosteum beneath it. If the procedure is designed as a semi-thick flap, the incision should be made at a depth of 121 to the connective tissue layer and not through the periosteum to the bone surface; the gingival flap is then sharply separated from the underlying connective tissue and periosteum with a sharp #11 or #l5 blade. The semi-thick flap method requires some skill and is only applicable to thicker gingival areas.