Subepithelial connective tissue grafts are a type of medical treatment used to help repair the gum tissue around your teeth. When there is not enough healthy gum tissue around your tooth, it can cause your teeth to become more vulnerable to decay and other problems. With a subepithelial connective tissue graft, a surgeon will take a small piece of skin from the roof of your mouth and use it to cover the exposed root of your tooth. This helps to protect and support the tooth, improving your smile and preventing further harm.