Abstract: Objective：To evaluate the differences of clinical parameters and putative periodontal pathogens in sites of different probing depth (PD) reduction after non-surgical periodontal treatment in patients with aggressive periodontitis (AgP). Methods: Clinical examinations including plaque index, probing depth (PD), attachment level (AL) and bleeding index (BI), and full-mouth periapical photographs were collected from 20 patients with AgP. All the patients received non-surgical periodontal treatment, including oral hygiene instruction, supra-gingival scaling, subgingival scaling and root planing (SRP) and were followed up for 6 months post-therapy. Gingival crevicular fluids (GCF) were collected at 1 site in each quadrant before and at the end of 6 months post-therapy. Six kinds of putative periodontal pathogens and 6 kinds of short chain fatty acids (SCFAs) were detected in the GCF samples. Results: The baseline clinical parameters of PD, AL and BI, the baseline concentration of succinic acid, acetic acid, propionic acid and butyric acid, and the prevalence of Treponema denticola were significantly higher in sites with PD reduction more than 2 mm sites compared with PD reduction no more than 2 mm sites ［(7.7±1.2) mm vs. (5.1±1.8) mm, (6.3±1.9) mm vs. (4.5±2.2) mm, 3.8±0.4 vs. 3.3±0.8, 1.66 mmol/L vs. 1.10 mmol/L, 31.67 mmol/L vs.17.78 mmol/L, 3.31 mmol/L vs.1.95 mmol/L, 84.6% vs. 56.1%, P<0.05］. However, there were no significant differences in the clinical parameters, the 6 kinds of putative periodontal pathogen detection and SCFAs concentration between the 2 groups at the end of 6 months post-treatment. In sites with PD>5 mm at the end of 6 months post-therapy, all were found with red complex bacteria infection. Conclusion: The baseline clinical parameters are important factors in predicting PD reduction after non-surgical periodontal treatment in patients with AgP. In sites with deep pockets after non-surgical periodontal treatment, the active control of red complex bacteria is recommended.

Key words: Aggressive periodontitis, Gingival crevicular fluid, Microbiology, Dental plaque