The occurrence of gingival recession is a precursor to the loss of cementum, the exposure of dentin, and the subsequent development of hypersensitivity. Recession can occur for a variety of reasons. Excessive and abrasive use of any oral hygiene device can lead to gingival recession, although toothbrush type and the technique used are the primary contributing factors. However, it is not believed that the toothbrush alone causes loss of enamel or cementum. Gingiva can be lost secondary to tissue destructive processes of periodontitis, necrotizing ulcerative gingivitis (NUG), and viral disorders, such as HIV. Surgical and non surgical periodontal treatment can result in gingival recession and root exposure. Certain other surgical and restorative procedures, such as crown preparations, may also contribute to gingival recession and root exposure.