Differences in subgingival microflora of Korean and German periodontal patients

Purpose: The goal of this study was to characterize the microbiological profile in samples of subgingival plaque taken from periodontal patients with different ethnic origin. Methods: 178 patients (n = 90 from South Korea and n = 88 from Germany; age: 45.4 = 10.4 years) were diagnosed with severe generalized periodontitis. In all patients the deepest pocket of each quadrant was sampled for subgingival plaque. The four samples per patient were pooled and subsequently analysed with a 16s-RNA-gene probe test. Results: Prevalence of Aggregatibacter actinomycetemcomitans was significantly higher in German patients (47.7%) compared to Korean patients (26.7%) (p < 0.01, X-2-test). For Tannerella forsythia and porphyromonas gingivalis, differences between Germans and Koreans were not as pronounced. A statistically significant difference could also be found for Treponema denticola (Germans: 95.5%, Koreans: 81.1%, p < 0.01, x(2)-test). After logarithmic transformation, bacterial counts differed for all microorganisms under investigation between Germans and Koreans, even after using a General Linear Model/Analysis of Covariance (GLM/ANCOVA) to adjust for gender, age, smoking status, pocket probing depths (PPD) of sampled teeth, and gingival bleeding index (GBI). Conclusion: Depending on their ethnic origin, the microbiological profile of pooled subgingival plaque sample seems to differ significantly between patients of Caucasian and Asian ethnic origin. (c) 2008 Elsevier Ltd. All rights reserved.