Physicochemical treatment against periodontopathic bacteria using 3DS and azithromycin

Objectives: The effectiveness of dental drug delivery system (3DS) as a local chemotherapy and systemic antibiotics in disinfection of periodontopathic bacteria was evaluated in this study. Additionally, the possibility of proportional changes in Porphyromonas gingivalis(Pg) to be one of the leading indicators among periodontitis examinations was sought. Methods: Physical treatment such as scaling, root planing, and PMTC (n=79) followed by chemotherapy (n=67) was performed on patients with mild and moderate periodontitis. As chemotherapy, 5-minute application of topical 10% povidone-iodine gel, more than 6-hour application (during sleeping) of minocycline-paste and systemic application of total 1500mg azithromycin were conducted. Following examinations were evaluated at the first visit and after each therapy: 1) periodontal pocket% (more than 4mm), 2) BOP% (the proportion of pockets with bleeding), 3) the number of Pg (copy/tube) and the proportion in the total bacteria by real time PCR. The ratio between total streptococci (FITC) and Pg (CY3) in the biofilm was observed by FISH at the first visit and after each physical and chemical treatment. Results: 1) Periodontal pocket% and BOP% were improved after physical treatment (p=2.94x10^-15, p<0.01), and chemotherapy (p=9.87x10^-8, p<0.01) on patients with periodontitis. 2) Disinfection of Pg was more significant after chemotherapy than after physical treatment (p=1.8x10^-5, p<0.05, OR: 5.1), while the total bacterial count did not change after each treatment. 3) The images of total streptococci (FITC) and Pg (CY3) obtained by FISH did not change after physical treatment. After chemotherapy, however, Pg significantly decreased. Conclusions: These findings indicate that not only physical treatment but chemotherapy seems to be needed for periodontal treatment. Moreover, the propotion of periodontopathic bacteria to total oral bacteria could be a leading indicator for evaluation of periodontal treatment.