ABSTRACT
Data from the United States National Institute of Dental and Craniofacial Research (NIDCR) indicate that more than 86% of adult populations over 70 years old have at least moderate level of periodontal-related diseases and over a quarter have lost their teeth (Nakashima and Reddi 2003). Periodontitis and gingivitis are the two most common periodontal-related inammatory diseases seen in adults. The progressive destruction of the tooth-support apparatus, including gingiva, alveolar bone, and periodontal ligament (PDL), and root cementum, if no clinical intervention, may ultimately lead to tooth loss (Haffajee and Socransky 1994; Pihlstrom et al. 2005; Nanci and Bosshardt 2006). Research ndings have suggested an association of periodontitis with various systemic disorders, such as diabetes, cardiovascular diseases, and respiratory diseases, thus considered as a chronic condition (Pihlstrom et al. 2005; Southerland et al. 2006; Nishimura et al. 2007).
