Quantification of Periodontopathogens in Periodontal Granulation Tissue Using Real-time PCR

Objectives: Since most forms of periodontal diseases are apparently caused by specific bacterial species, treatment should be directed towards elimination of the periodontal pathogens. Identification of invading organisms is of great importance in order to determine their role in the pathogenesis of the disease and treatment strategy. The aim of our study is to investigate the quantity of periodontal bacteria invaded into diseased gingival tissue in periodontitis. Methods: 32 Chronic Periodontitis (CP) patients, 15 Generalized Aggressive Periodontitis (GAgP) patients and 7 Localized Aggressive Periodontitis (LAgP) patients were recruited in our study. After initial periodontal treatment, flap surgery was performed at sites with periodontal pocket deeper than 5 mm. Granulation tissue samples were collected during flap surgery. Real-time PCR method was utilized to investigate the quantification of periodontopathogens such as Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsynthensis. Kruskal-Wallis test with Bonferroni type multiple comparison were applied for statistical analysis. Results: The detection frequencies of A. actinomycetemcomitans in tissues samples in LAgP, GAgP and CP were (71%), (33%) and (16%). Statistical significance was found between LAgP and CP. Frequencies of P. gingivalis and T. forsynthensis were (100%) and (100%) in LAgP, (87%) and (91%) in CP, (80%) and (100%) in GAgP, respectively. For bacterial quantity, there was statistically difference between the log transformed numbered of A. actinomycetemcomitans in LAgP (2.214) and in CP (0.575).Quantities of P. gingivalis and T. forsynthensis were not markedly different in tissues samples among CP, GAgP and LAgP. Conclusion: Our results indicated that A. actinomycetemcomitans in LAgP was frequently detected and at a high quantity in diseased gingival tissues. Detection frequencies of P. gingivalis and T. forsynthensis were still high in advanced periodontitis although initial periodontal treatment was performed. Those bacteria might be difficult to be eliminated once they invaded into gingival tissues.