Periodontopathogens and human β‐defensin‐2 expression in gingival crevicular fluid from patients with periodontal disease in Guangxi, China

BACKGROUND AND OBJECTIVE: Periodontal diseases are often induced by periodontopathogens, which are always exposed to certain innate immune factors in gingival crevicular fluid, including human β-defensin-2 (hBD-2). This study aims to investigate the relationship among periodontopathogens, clinical parameters and hBD-2 expression. MATERIAL AND METHODS: Thirty-two healthy controls, 42 patients with chronic gingivitis and 95 patients with chronic periodontitis were recruited in Guangxi, China. Bleeding index, probing depth and clinical attachment level were measured for all teeth including mesiobuccal, buccal, disobuccal, mesiolingual, lingual, disolingual six sites of all patient. Gingival crevicular fluid samples were collected from the study sites. The prevalence and copy numbers (CN) of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia and total bacteria in gingival crevicular fluid were quantified by real-time PCR. The hBD-2 concentration in gingival crevicular fluid was measured by ELISA. RESULTS: Both the prevalence and the CN of A. actinomycetemcomitans, P. gingivalis, T. denticola and T. forsythia were higher in patients with chronic periodontitis than in healthy controls and patients with chronic gingivitis; however, there was no significant difference in the prevalence of P. intermedia among the three study groups, and the highest CN was found in patients with chronic gingivitis, rather than in patients with chronic periodontitis. The loads of P. gingivalis, P. intermedia, T. denticola and total bacteria were positively related to probing depth, bleeding index and clinical attachment level. The concentration of hBD-2 in gingival crevicular fluid was higher in patients with chronic gingivitis and in patients with chronic periodontitis than in healthy controls. In addition, the hBD-2 concentration was positively related to the CN of P. gingivalis, T. forsythia and total bacteria, as well as to bleeding index and probing depth. CONCLUSION: The prevalence, composition and CN of periodontopathogens were closely related to the severity of periodontal disease, and the red complex was related to the severity of clinical symptoms of periodontal diseases. The concentration of hBD-2 in gingival crevicular fluid from periodontal disease sites was higher than that in gingival crevicular fluid from healthy sites, which suggests that hBD-2 expression might be up-regulated by periodontopathogens.