Objective:To investigate the inhibitory effects of different concentrations of chlorhexidine in the development of peri-odontitis models in rats.Methods:periodontitis models were established by the ligation of bilateral first molars and orally challenge with P.gingivalis W83.0.05%,0.1%,0.2% and 0.5% chlorhexidine were used to wash the periodontal pocket and oral mucosa of the rats.4 weeks later,absolute real time quantitative PCR was used to count the copy of P.gingivalis W83 in rat periodontal pockets.Scanning electron microscopy was used to observe the distribution of P.gingivalis W83 on rat teeth surface.Immunohisto-chemical technique was used to detect the expression of TNF-αin gingival tissue of the rats.Results:0.2% and 0.5% chlorhexi-dine reduced the copy of P.gingivalis W83 on teeth surface and in periodontal pockets (P <0.05);0.1% -0.5% chlorhexidine reduced the expression of TNF-αin gingival tissue (P <0.05).Conclusion:0.1% -0.2% chlorhexidine can inhibit the develop-ment of chronic periodontitis in rats.

The relationship between periodontal disease and systemic diseases more and more get the attention of scholars in recent years. This paper illustrates the influence of periodontal disease on the systemic diseases, which prompt that periodontal disease may be the potential risk factor of causing or aggravating the systemic disease. The treatment of periodontal disease can reduce and prevent the occurrence and development of some systemic diseases,which play an important role in maintaining the whole body health.

OBJECTIVETo investigate the effects of serum from smoking individuals or non-smoking individuals with periodontitis on Porphyromonas gingivalis (Pg) internalizing KB cells, and the expression of matrix metalloproteinase(MMP)-1, MMP-9, tissue inhibitor of metalloproteinase-1 (TIMP-1) in the culture supernatant of KB cells.

METHODSThe venous blood of 20 periodontitis patients' (10 smoking and 10 non-smoking) was extracted under the informed consent and centrifuged for serum. The smoking-individual serum (Y group) and non-smoking-individual (N group) serum were added to the model of Pg internalizing KB cells for 12 hours, plated on brain-heart infusion (BHI) and incubated anaerobically at 37 °C for 5 days. The colony forming units (CFU) of cell-invasive bacteria were estimated by colony counting. MMP-1, MMP-9 and TIMP-1 protein levels in culture supernatant were determined by enzyme-linked immunosorbent assay(ELISA) in the two groups following co-culture of Pg with KB cells for 12 hours.

RESULTSThe CFU were (11.2 ± 1.1)×10(4), (12.6 ± 1.2)×10(4), (44.7 ± 1.3)×10(4) CFU/ml when adding 200, 400, 800 µl Y-group serum to the model of Pg co-culture with KB cells and when the serum was extracted from N group, the CFU were (33.6 ± 1.4)×10(4),(38.9 ± 1.1)×10(4), (11.2 ± 1.2)×10(4) CFU/ml respectively. When 200, 400, 800 µl Y group-serum was added to co-culture fluid of Pg internalizing KB cells, the concentrations of MMP-1 secreted from KB cells were (107.2 ± 21.5), (165.9 ± 20.2), (434.4 ± 48.0) µg/L respectively, the concentrations of MMP-9 were (3.99 ± 0.29), (4.21 ± 0.61), (5.62 ± 0.47) µg/L respectively, the concentrations of TIMP-1 were (401.3 ± 12.7), (418.3 ± 28.5), (637.3 ± 37.3) µg/L. When the serum (200, 400, 800 µl) extracted from N group, the concentration of MMP-1 and MMP-9 secreted by KB cell were (77.6 ± 10.8), (84.7 ± 10.2) and (98.2 ± 9.7) µg/L and (3.84 ± 0.52), (4.02 ± 0.68), (4.25 ± 0.37) µg/L, respectively. The concentration of TIMP-1 were (67.3 ± 26.9) , (89.4 ± 22.7) and (78.2 ± 16.5) µg/L secreted by KB cells in the course of Pg internalized KB cell. With the increasing of Y group-serum, the more MMP-1, MMP-9 and TIMP-1 were secreted by KB cells(P < 0.05). When 800 µl Y group-serum was added compared with N group-serum to the Pg co-culture with KB model, the more MMP-1, MMP-9 and TIMP-1 were secreted by KB cells(P < 0.05), when 400 µl Y group-serum was added compared with N group-serum to the Pg co-culture with KB model, the more MMP-1 and TIMP-1 were secreted by KB cells (P < 0.05).

CONCLUSIONSThe smoking-serum might enhance Pg internalizing KB cells and enhance the expression of MMP-1, MMP-9 and TIMP-1 secreted from KB cells. The local microenvironment of smoking individual may contribute to the recurrence and progression of chronic periodontitis.

Coculture Techniques ; Humans ; KB Cells ; Matrix Metalloproteinase 1 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Porphyromonas gingivalis ; enzymology ; RNA, Messenger ; Serum ; Smoking ; Tissue Inhibitor of Metalloproteinase-1 ; metabolism

Objective: To detect the inhibitory ability of histatin 5 on the auto-aggregation of Porphyromonas gingivalis (Pg), and the co-aggregation of Pg with Fusobacterium nucleatum (Fn); and to provide a theoretical basis for the role of oral innate immunity played in the inhibition of chronic periodontitis. Methods: Saliva and supragingival, subgingival plaque samples were collected from 49 chronic periodontitis patients in School of Stomatology, China Medical University and 27 periodontal healthy individuals. Enzyme linked immunosorbent assay was used to assess the amount of histatin 5 in saliva, absolute quantitative real-time PCR (qPCR) was applied to detect the DNA copies of Fn, Pg and total bacteria in supragingival and subgingival plaque samples. The effects of histatin 5 on auto- and co-aggregation were assessed by bacterial adhesion test and scanning electron microscopy. Hemagglutinin gene, arginine-gingipains gene in Pg and FomA gene in Fn were tested by relative qPCR. Independent samples t-test was used to calculate the significance between the experimental group and the control group. P-value<0.05 was considered statistically significant. Results: For chronic periodontitis patients, there was an inverse correlation between the concentration of histatin 5 and Fn and Pg in supragingival plaque samples (r=-0.379, r=-0.624). Similarly, an inverse correlation was also observed between the concentration of histatin 5 and subgingival Fn and Pg, respectively (r=-0.404, r=-0.314). As for periodontally healthy individuals, there was an inverse correlation between the concentration of histatin 5 and supragingival and subgingival Pg (r=-0.572, r=-0.533). Bacterial adhesion test and scanning electron microscopy certified that 25 mg/L histatin 5 inhibited the auto-aggregation of Pg-Pg and the co-aggregation of Pg-Fn. Results of qPCR showed that 25 mg/L histatin 5 up-regulated hemagglutinin gene by (14.52±3.25) fold and down-regulated FomA gene to (0.22±0.10) fold. Conclusions Histatin 5 could inhibit the auto-aggregation of Pg-Pg and the co-aggregation of Pg-Fn by regulating hemagglutinin gene and FomA gene expression.