Effect of Porphyromonas gingivalis infection on atherosclerosis in apolipoprotein-E knockout mice / 北京大学学报(医学版)

OBJECTIVE@#Studies have indicated that periodontal pathogen Porphyromonas gingivalis (P. gingivalis) infection may contributed to accelerate the development of atherosclerosis. The aim of this study was to investigate the effect of inflammation, oxidative stress and the mechanism on atherosclerosis in apolipoprotein-E knockout (ApoE-/-) mice with P. gingivalis infection.@*METHODS@#Eight-week-old male ApoE-/- mice (C57BL/6) were maintained under specific pathogen-free conditions and fed regular chow and sterile water after 1 weeks of housing. The animals were randomly divided into two groups: (a) ApoE-/- + PBS (n=8); (b) ApoE-/- + P.gingivalis strain FDC381 (n=8). Both of the groups received intravenous injections 3 times per week for 4 weeks since 8 weeks of age. The sham control group received injections with phosphate buffered saline only, while the P. gingivalis-challenged group with P.gingivalis strain FDC381at the same time. After 4 weeks, oxidative stress mediators and inflammation cytokines were analyzed by oil red O in heart, Enzyme linked immunosorbent assay (ELISA) in serum, quantitative real-time PCR and Western blot in aorta.@*RESULTS@#In our study, we found accelerated development of atherosclerosis and plaque formation in aorta with oil red O staining, increased oxidative stress markers [8-hydroxy-2-deoxyguanosine (8-OHdG), NADPH oxidase (NOX)-2 and NOX-4], as well as increased inflammation cytokines [interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α)] in the serum and aorta of the P. gingivalis-infected ApoE-/- mice. Compared with the control group, there was a significant increase protein level of nuclear factor-kappa B (NF-κB) in aorta after P. gingivalis infection.@*CONCLUSIONS@#Our results suggest that chronic intravenous infection of P. gingivalis in ApoE-/- mice could accelerate the development of atherosclerosis by disturbing the lipid profile and inducing oxidative stress and inflammation. The NF-κB signaling pathway might play a potential role in the P. gingivalis-accelerated atherogenesis.

Tooth loss and multivariable analysis after 5-year non-surgical periodontal treatment on molars with furcation involvement / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the tooth loss status of mandibular molars with furcation involvements after 5-year non-surgical periodontal treatment, and to analyze the factors that affected the tooth loss.@*METHODS@#A retrospective analysis was conducted in 79 patients with chronic periodontitis, who had received non-surgical periodontal treatment and 5 years of periodontal maintenance treatment in Department of Periodontology, Peking University School and Hospital of Stomatology from 1988 to 2012. Their clinical indexes, including probing depth (PD), bleeding index (BI), furcation index (FI) and tooth mobility were both evaluated before treatment and at the last time of the maintenance treatment. Bone resorption at furcation area was measured at the first visit by periapical radiographs taken by professional doctors of medical imaging. The status of tooth loss after 5-year non-surgical periodontal treatment on mandibular molars with furcation involvement, and the factors that affected the tooth loss were analyzed.@*RESULTS@#(1) Non-surgical treatment was significantly effective on the changes of PD in the patients of chronic periodontitis with furcation involvement, while the presence of furcation involvement could affect the improvement of PD here. (2) PD at the furcation area, tooth mobility, vertical bone resorption, and bone resorption area were all significant risk factors of mandibular molar missing (P<0.001), and the same with FI=3 and FI=4 (P=0.017, P=0.007), while age (P=0.703), gender (P=0.243) and smoking history (P=0.895) were not related to the tooth loss in this study. (3) The risk of tooth loss in mandibular molars with FI≥3 were significantly higher than those with FI≤2, and the survival rate of the former was less than 50%.@*CONCLUSION@#The loss of mandibular molars with furcation involvement was related to the furcation involvement, meanwhile the degree of furcation involvement and bone resorption can significantly increase the risk of tooth loss.

Correlation between cigarette smoking and periodontal status: A survey on the population of a community above 35-year-old in Beijing / 北京大学学报(医学版)

OBJECTIVE@#To survey the cigarette smoking status and periodontal status, and to study the correlation between cigarette smoking and periodontal status.@*METHODS@#Questionnaires were distributed (including self-assessed periodontal status, such as bleeding while brushing teeth, oral odor, tooth loosening, gum swelling, etc.) and clinical periodontal examinations performed for parameters including probing depth (PD), bleeding index (BI), attachment loss (AL), plaque index (PLI) and amount of teeth loss, which was recorded in the population above 35 years of a community in Beijing. A total of 974 subjects were recruited in the study. The population was divided into current smokers and non-smokers, and the differences of self-assessed periodontal status and periodontal parameters between the groups analyzed.@*RESULTS@#The smokers had significantly less bleeding during toothbrushing, and in the meantime, had significantly more self-reported tooth loosening compared with the non-smokers. The smokers brushed their teeth less than the non-smokers (P<0.05). The self-reported gum swelling and oral odor had no significant difference between the smokers and non-smokers. The smokers had 0.565 times and 1.572 times the risk of bleeding during toothbrushing, self-reported tooth loosening and from Logistic regression analyses, respectively (P<0.05). The mean PD, AL, PLI and the amount of tooth loss of the smokers were significant higher than the non-smokers (P<0.05). However, the mean BI of the smokers was slightly less than the non-smokers' (1.93±0.540 vs. 1.94±0.512, P=0.707). The smokers had 2.129 times, 1.698 times and 1.933 times the risk of the mean PD>3 mm, the mean AL>3 mm, and the amount of tooth loss above 8, respectively compared with the non-smokers (P<0.05) from Logistic regression analyses.@*CONCLUSION@#The self-assessed periodontal status is different between smokers and non-smokers in the population of a community in Beijing. Smokers have less bleeding during toothbrushing but no significant difference with BI. Smokers also have more self-reported tooth loosening. Compared with non-smokers, smokers have more severe periodontal destruction.

Association between chronic periodontitis and carotid intima-media thickness of middle-aged and older adults in Shijingshan community of Beijing / 北京大学学报(医学版)

OBJECTIVE@#To investigate the relationship between periodontal disease and subclinical atherosclerosis in middle-aged and older adults in Shijingshan community of Beijing.@*METHODS@#In 2005-2010, a total of 830 middle-aged and older adults were recruited from Shijingshan community of Beijing, who were divided into two groups by severity of periodontitis. A questionnaire, periodontal examination, blood biochemical examination, carotid intima-media thickness (CIMT), including common carotid artery (CCA-IMT), internal carotid artery (ICA-IMT) and carotid bifurcation (CB-IMT), were measured of each subject. The associations of periodontitis with CIMT was evaluated by multivariable Logistic regression analysis and analysis of covariance, adjusted for age, gender, education level, hypertension, hyperlipidemia, obesity, smoking, drinking, and diabetes. And then anther definition of periodontitis (mild periodontitis: percentage of AL≥3 mm <10%; moderate periodontitis: percentage of AL≥3 mm 10%-30%; severe periodontitis: percentage of AL≥3 mm ≥30%) was used to investigate the hypotheses that different classification of periodontitis would affect results.@*RESULTS@#The subjects with moderate-severe periodontitis were characterized by significantly higher levels of CCA-IMT, ICA-IMT, CB-IMT and mean CIMT than the mild group. In the univariate analysis, moderate-severe periodontitis was associated with an increased risk of ICA-IMT>0.9 mm (adjusted OR=1.230, 95% CI: 1.058-1.452, P=0.031). Furthermore, moderate periodontitis was associated with an increased risk of CB-IMT>0.9 mm (adjusted OR: 1.297, 95%CI: 1.117-1.753, P=0.011) and severe periodontitis was associated with an increased risk of CB-IMT>0.9 mm (adjusted OR=1.771, 95%CI: 1.176-3.503, P=0.042) according to another classification of periodontitis.@*CONCLUSION@#Our data provided evidence that periodontitis was associated with CIMT among middle-aged and older adults in Shijingshan community of Beijing and different periodontitis classification would affect the results.

Levels of tumor necrosis factor-alpha and interleukin-1beta in saliva of metabolic syndrome patients / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the association between periodontitis and the low-grade inflammation in metabolic syndrome (MS) patients.</p><p><b>METHODS</b>Fifty-seven MS patients, 26 healthy controls were enrolled. Non-stimulated whole saliva was collected. The levels of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta was analyzed by radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Concentration of cytokines was compared between MS patients and the healthy controls. Correlations between the cytokines and various periodontal indices, and between the cytokines level and different quantity of metabolic syndrome components were also investigated.</p><p><b>RESULTS</b>Levels of TNF-alpha in saliva of MS patients [(69.30+/-21.01) ng/L] were significantly higher than that in the healthy subjects [(57.85+/-15.69) ng/L, P<0.05], and of IL-1beta in MS patients [(616.42+/-360.05) ng/L] higher than that in healthy subjects [(506.06+/-245.76) ng/L], but the difference was not statistically significant. TNF-alpha was positively correlated with bleeding index (BI). In MS patients, TNF-alpha level and IL-1beta level increased with increasing severity of periodontal disease and increasing component numbers of MS.</p><p><b>CONCLUSIONS</b>Periodontal inflammation may be one of the sources of low-grade inflammation in MS patients. Both systemic and periodontal conditions may influence the level of salivary TNF-alpha and IL-1beta.</p>

Effect of verapamil on the proliferation of normal gingival fibroblast / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the effect of verapamil on the proliferation of normal gingival fibroblast (NGF) in vitro.</p><p><b>METHODS</b>NGF was isolated and cultured. The 5th passage of NGF was incubated with 0, 0.1, 1, 10, 100 micromol/L verapamil respectively. Methyl thiazolyl tetrazolium (MTT) assay and flow cytometry were used to detect cell proliferation and cell cycles.</p><p><b>RESULTS</b>Incubated with 100 micromol/L verapamil for 66 h, the A value of normal gingival fibroblast was significantly lower than those without verapamil groups (P < 0.01). Incubated with 100 micromol/L verapamil for 18 h, 69% of cells were at the G(0) - G(1) phase, 27% were at the S phase. For control group (without verapamil) 41% of cells were at G(0) - G(1) phase and 49% cells were at S phase. There was significant difference between the two groups (P < 0.001).</p><p><b>CONCLUSIONS</b>100 micromol/L verapamil inhibited proliferation of normal gingival fibroblast by a cell-cycle arrest.</p>

Analysis of risk indicator for nifedipine-induced gingival hyperplasia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence and risk indicator of nifedipine-induced gingival overgrowth in a community population in Beijing.</p><p><b>METHODS</b>A cross-sectional survey was conducted in 616 community subjects with hypertension or coronary vascular disease in Beijing, China. Among them 205 individuals took nifedipine for at least half year and 411 individuals who had never received calcium channel blocker (CCB) were recruited as controls. Smoking, oral hygienic habit, systemic health, pharmacological and demographic data for each subject were recorded by questionnaire. Sulcus bleeding index (SBI) was assessed in 12 anterior teeth per subject. Turesky modified Quigley-Hein plaque index (PI) and gingival overgrowth index in anterior teeth were scored on photograph. 38.6% was defined as threshold to identify individual with significant gingival overgrowth.</p><p><b>RESULTS</b>7.3% of the subjects taking nifedipine were found to have significant gingival overgrowth in this population. The prevalence of gingival overgrowth in nifedipine group was statistically higher than that in the control group. By logistic regression analysis, SBI was found to be the only risk indicator (odds ratio = 5.92, P = 0.001).</p><p><b>CONCLUSIONS</b>The presence of gingival inflammation was an important cofactor for the occurrence of gingival overgrowth.</p>

Analysis of dental plaque by using cellular neural network-based image segmentation / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish and evaluate a new method for measurement of dental plaque by using cellular neural network-based image segmentation.</p><p><b>METHODS</b>A total of 195 subjects were selected from community population. After dental plaque staining, oral digital picture of anterior teeth area was taken by an Olympus digital camera (C-7070 Wide Zoom). At the same time, the Turesky dental plaque indices of anterior teeth were evaluated. The image analysis was conducted by cellular neural network-based image segmentation.</p><p><b>RESULTS</b>The image cutting errors between two operators were very small. The Kappa value is 0.935. Pearson's correlation coefficient is 0.988 (P < 0.001). There was high correlative consistency between traditional dental plaque index and plaque percentage obtained by using image analysis. Pearson's correlation coefficient was 0.853 (P < 0.001).</p><p><b>CONCLUSIONS</b>Cellular neural network-based image segmentation is a new method feasible for evaluating dental plaque.</p>

Computerized image processing in esthetic rehabilitation of anterior teeth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the application of computerized image processing in esthetic rehabilitation of anterior teeth.</p><p><b>METHODS</b>Thirteen patients with esthetic problems in anterior teeth were included in this study. Oral digital images were obtained before and during treatment with a digital camera. All the oral esthetic data of the patients, including tooth shape, tooth shade, tooth characteristic color, incisal transparency, incisal curve, smile line, and gingival curve et al, were collected and analyzed. Diagnostic images of the anticipated esthetic outcome were created by computerized image processing software and transferred to the technician. Restorations were made according to the images by the technician.</p><p><b>RESULTS</b>All anterior teeth of 13 patients were restored with this method and good esthetic results were achieved.</p><p><b>CONCLUSIONS</b>Computerized image processing is a useful method in the esthetic rehabilitation of anterior teeth.</p>