Gum Grafts
            Tooth roots that are exposed due to gum recession may be sensitive to hot and cold foods or liquids, and they make teeth appear long. Gum recession can put you at risk of developing a cavity on the tooth root, and may lead to bone loss, eventually resulting in tooth loss. Soft tissue grafts, which move healthy gum tissue from one part of the mouth to another, can stop gum recession and bone loss and improve the esthetics of the gum line.

Gum Grafting Procedures
            Body loses a natural defense against both bacterial penetration and trauma when recession of the gingiva occurs. When gum recession is a problem gum reconstruction using grafting techniques is an option. This is critical to understand because after minor gum recession is left untreated, continued recession always is combined with bone loss around teeth.  Incase of only minor recession, some healthy gingiva (the strong, pink, non-movable gum tissue which surrounds our teeth) often remains and protects the tooth, so that no treatment other than modifying home care practices is necessary. However, when recession reaches the mucosa (the red, movable weaker tissue), the first line of defense against bacterial penetration is lost. It is at this point that bone loss has also initiated. Root sensitivity to hot and cold foods as well as an unsightly appearance to the gum and tooth results in due to  gum recession. Also, gum recession, when significant, can predispose to worsening recession and expose the root surface, which is softer than enamel, leading to root caries and root gouging.
            Surgery of  gingival graft is designed to solve these problems. A thin piece of tissue is grafted from the roof of the mouth, or gently moved over from adjacent areas, to provide a stable band of attached gingiva around the tooth. The gingival graft may be placed in such a way as to cover the exposed portion of the root. The gingival graft procedure is highly predictable and results in a stable healthy band of attached tissue around the tooth. Surgical innovations in the past 20 years have drastically changed these grafting procedures. The piece of gingiva from the palate is no longer left as an open would causing patient discomfort. In addition, in some cases, an allograft can be utilized. This is a piece of tissue that is taken from a donor, in the same fashion as a bone graft, and treated by groups like the American Red Cross. No disease transmission has ever been reported with the allografts in dentistry. They circumvent the need to graft form patients palates to add attached gingiva (pink gum tissue) around teeth.
Reference:
MedlinePlus