Objective: To investigate if high glucose (HG) exacerbates Porphyromonas gingivalis (P.g) lipopolysaccharide (LPS)-induced inflammatory response in human gingival fibroblasts (HGFs) and to explore the underlying mechanisms. To provide a basis for the mechanism of diabetes aggravating periodontitis. Methods: HGFs were divided into four groups: the control group (basal medium), the LPS group (treated with 5 μg/mL P.g-LPS for 24 h), the HG group (treated with 25 mmol/L glucose for 24 h), and the HG+LPS group (treated with 25 mmol/L glucose + 5 μg/mL P.g-LPS for 24 h). After culturing for 24 h in the respective media, the cells were harvested for experiments. Intracellular reactive oxygen species (ROS) and mitochondrial reactive oxygen species (mtROS) were detected using 2 ', 7' - dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSOX Red staining, respectively. Fluorescence intensity was analyzed by confocal fluorescence microscopy and directly measured in cell suspension. Immunofluorescence was used to detect changes in mitochondrial DNA (mtDNA) content of HGFs. Real-time fluorescence quantitative PCR was used to detect the content of mtDNA in cytoplasm and cell supernatant. Protein expression of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway was assessed by western blot, while mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were detected by PCR. Results: Compared to the control group, both the LPS group and the HG group exhibited a significant increase in ROS and mtROS, with a more pronounced elevation in the HG+LPS group, demonstrating a synergistic effect (ROS: F = 396.5, P < 0.001; mtROS: F = 29.38, P < 0.001, CI < 1). The cytoplasmic mtDNA content was significantly elevated in the LPS group, with a more marked increase in the HG+LPS group (F = 27.85, P < 0.001). The supernatant mtDNA levels were significantly higher in both the LPS and HG groups, with a more pronounced elevation in the HG+LPS group (F = 15.26, P < 0.001). The phosphorylated proteins p-STING, p-TBK1, and p-P65 in the cGAS-STING pathway showed varying degrees of activation in the LPS and HG groups, reaching the highest levels in the HG+LPS group (p-STING: F = 52.67, P < 0.001; p-TBK1: F = 15.67, P = 0.001; p-P65: F = 9.83, P = 0.005), while p-IRF3 showed no significant differences among the groups (P = 0.072). Pro-inflammatory cytokine TNF-α was significantly higher in the HG+LPS group compared to the control group (F = 15.05, P < 0.001), and IL-1β increased in both the LPS and HG groups, with a more pronounced rise in the HG+LPS group (F = 30.98, P < 0.001). IL-6 showed no significant differences among the groups (P = 0.847). Conclusion High glucose and LPS act synergistically to enhance oxidative stress, accompanied by increased mtDNA release, which activates the cGAS-STING pathway, thereby amplifying the inflammatory response in HGFs.

Objective To investigate the impact of metabolic labeling on Porphyromonas gingivalis(Pg)and com-pare the imaging effects of two fluorescent probes.Methods This study was reviewed by the unit Ethics Committee and was approved by the Experimental Animal Welfare Ethics Branch of the Unit Experimental Biomedical Ethics Com-mittee.Pg integrated N-azidoacetylgalactosamine(Ac4GalNAz)via a bioorthogonal reaction and was labeled with Cy5-DBCO or Cy7-DBCO via a click chemistry reaction.The bacteria were divided into Pg group(control,not fluorescently labeled),Cy5-Pg group(tagged by Cy5-DBCO),and Cy7-Pg group(tagged by Cy7-DBCO).A live/dead staining kit was applied to test the viability of Pg,Cy5-Pg,and Cy7-Pg.The mRNA levels of interleukin-6(IL-6)and IL-8 and cell pro-liferation were examined in human gingival fibroblasts(HGFs)after the challenge of Cy5-Pg,Cy7-Pg,or Pg.To investi-gate the stability of metabolic labeling,Cy5-Pg or Cy7-Pg was cocultured with Escherichia coli(E.coli).Cy5-Pg and Cy7-Pg signal intensity with serial dilutions were examined using an in vivo imaging system(IVIS).Finally,C57BL/6J mice were orally administered Cy5-Pg or Cy7-Pg for IVIS detection,and the signal-to-background ratios were calculated.Results Metabolic labeling could be applied to label live Pg in vitro.The optimal labeling concentrations for Cy5 and Cy7 were 20 μmol/L and 30 μmol/L,respectively.The area ratios of live to dead bacteria were approximately 2.0 in the three groups(F=0.318,P＞0.05).After a 6-h challenge with Cy5-Pg,Cy7-Pg,or Pg,the mRNA levels of HGFs in-creased by 7.86-,7.46-,and 6.56-fold for IL-6,respectively(F=40.886,P＜0.001)and 12.43-,13.03-,and 13.71-fold for IL-8(F=18.781,P＜0.01),were spectively,compared to that of the Ctrl group,which was not challenged by bacte-ria,where no significant differences were observed among the three groups(P＞0.05).HGFs were further challenged by Cy5-Pg,Cy7-Pg,or Pg at different MOIs,and cell proliferation was significantly inhibited(MOI=104∶1,F=153.52,P＜0.001;MOI=105∶1,F=331.21,P＜0.001;MOI=106∶1,F=533.65,P＜0.001),with no significant differences among the three groups(P＞0.05).Within 24 h of co-culturing Cy5-Pg or Cy7-Pg with E.coli,minimal E.coli was de-tected.The intensities of Cy5 and Cy7 remained stable for 3 h.Additionally,the fluorescence signal intensities of Cy5 and Cy7 were linearly correlated with the concentration(R2=0.97).After oral gavage of Cy5-Pg or Cy7-Pg in mice for the abdominal region at 1 h and 3 h,the signal-to-background ratios of Cy7-Pg were approximately 4.24-fold(t=6.893,P＜0.01)and 3.77-fold(t=4.407,P＜0.05)higher,respectively,than those of Cy5-Pg.For the isolated gastrointestinal tracts at 3 h,the signal-to-background ratio of Cy7-Pg was 5.19-fold higher than that of Cy5-Pg(t=4.418,P＜0.05).Conclusions Metabolic labeling did not significantly affect viability,immunomodulatory ability,and toxicity.The im-aging effect of Cy7 on IVIS was better than that of Cy5.Our study provided experimental evidence for the correlation be-tween periodontitis and overall health.

Objective:To examine the association between macrophage migration inhibitory factor(MIF), Interleukin 6(IL-6), periodontal disease, and atherosclerosis in middle-aged and elderly individuals.Methods:This cross-sectional study enrolled 700 diabetic patients who were attending the endocrinology department of Beijing Hospital from January 2020 to December 2022.Out of these patients, 491 underwent a full-mouth periodontal examination.Among them, 106 were middle-aged and elderly.The study included 83 patients with complete data, aged between 45 and 70 years(mean age: 58.2±8.7 years).Among the included patients, 48 were male(57.8%)and 35 were female(42.2%).A questionnaire was administered to gather information about the patients, and serum levels of MIF and IL-6 were measured using enzyme-linked immunosorbent assay(ELISA).The relationship between serum MIF and IL-6 levels and periodontitis and atherosclerosis was evaluated through univariate and multifactorial analyses conducted on middle-aged and elderly individuals.Results:There were 66 cases(79.5%)in the periodontitis stage Ⅰ/Ⅱ group and 17 cases(20.5%)in the stage Ⅲ/Ⅳ group.The serum MIF levels in the two groups were(2, 312.5±795.0)ng/L and(2, 939.8±665.0)ng/L, respectively( P<0.01).Similarly, IL-6 levels were(3.5±3.0)ng/L and(6.7±6.1)ng/L in the two groups( P>0.05).The findings revealed that for each 1 ng/L increase in MIF serum levels, the risk of severe periodontitis and increased carotid intima-media thickness(cIMT)increased by 0.1%.Furthermore, for each 1 ng/L increase in serum MIF and IL-6 levels, the risk increased by 0.2% and 38.9% respectively.Serum MIF levels were found to be associated with atherosclerosis as well as with various factors related to periodontitis, including periodontal probing depth, bleeding index, clinical attachment level, periodontal probing depth≥4 mm sites, clinical attachment level≥5%, and bleeding index >2%(all P<0.05). Conclusions:This study investigates the correlation between MIF and IL-6 levels with Periodontal disease and Atherosclerosis in middle-aged and elderly individuals.

Objective: To investigate the influence of mechanical debridement on the subgingival microbiome in chronic periodontitis by 16S rRNA high-throughput sequencing. Methods: Patients with generalized moderate to severe chronic periodontitis were recruited into this study and received oral hygiene instruction and supragingival scaling. One week later, they received ultrasonic and manual subgingival scaling and root planning. Clinical parameters were recorded and subgingival plaques were sampled at baseline and 3 months and 6 months after treatment. The comprehensive profiles of the subgingival microbiome were analyzed by sequencing the V3-4 region of 16S rRNA with the Illumina MiSeq platform. Results : Alpha diversity analysis showed that the richness and diversity of the subgingival community were consistent before and after treatment, but a significant difference in community structure was detected only between baseline and month 3 by principal coordinates analysis (PCoA). After 3 months, the clinical parameter as probing depth (PD) decreased significantly and the relative abundances of the genera related to periodontitis such as Porphyromonas, Treponema, Tannerella, and Filifactor decreased significantly. Meanwhile, the relative abundances of the genera associated with periodontal health increased, such as Capnocytophaga, Kingella. Six months later, however, less genera related to periodontitis decreased significantly from the baseline level, such as Filifactor. PD decreased significantly compared with baseline, but increased significantly compared with 3 months after treatment. Conclusion Mechanical debridement alone could relieve periodontal inflammation and balance microbial dysbiosis and the greater efficacy occurred 3 months after treatment.

Objective:To investigate the status quo of human resources of dentists who deal with periodontal disease in Beijing area through an online survey, which may hopefully provide a preliminary basis for the decision-making of administrative departments and the formulation of periodontal professional development plan.Methods:The dentists who deal with periodontal disease at least half a day per week in Beijing area were investigated. A questionnaire was designed by the chairman of the Periodontology Committee of Beijing Stomatological Association. The questionnaire was sent to and finished by the dentists via "WenJuanXing" online survey software. The contents of the survey included general condition, the property of practice unit, title and position of the dentist, membership of professional society, time and content of periodontal treatment, adoption of new technology and new method of periodontal therapy during the past one year, status of periodontal treatment in the local population and reasons, understanding and influencing factors of periodontal professional development.Results:A total of 1 255 dentists completed the survey, who came from all 16 districts in Beijing, mainly Haidian, Chaoyang, Dongcheng and Xicheng Districts [The total percentage of these four main districts was 70.3% (882/1 255)]. The mean age of the dentists was (36.1±8.3) years. Among the dentists, 71.1% (892/1 255) were females, 88.1% (1 106/1 255) got a Bachelor′s degree or above. It was estimated that 35.4% (444/1 255) of the dentists had received standardized periodontal training ever. The percentage of dentists carrying out new technology in the past one year was as high as 68.1% (855/1 255). There were only 163 periodontal specialists (13.0%) out of the dentists in the survey. Only 15.9% (200/1 255) of the dentists routinely performed periodontal surgery. The majority of the dentists [82.8% (1 039/1 255)] were from the state-owned hospitals. Fifty-four point seven percemt (686/1 255) of the dentists thought that lack of knowledge was the main reason why the general public failed to receive periodontal treatment. As for the biggest bottleneck affecting periodontal professional development, fifty-one point zero percent (640/1 255) of the dentists attributed it to the public neglect.Conclusions:The periodontal practitioners in Beijing are young, highly educated, unevenly distributed in 16 districts and mostly females. State-owned oral health institutions are an important force in periodontal diagnosis and treatment services in Beijing. The number of periodontal specialists need to be improved. Promotion of standardized periodontal surgery and the popularization of healthcare knowledge on periodontal disease should also be the focus in the future.

Objective:To investigate the correlation between clinical periodontal indexes of periodontitis and glomerular filtration rate (GFR) in a non-diabetic elderly population in four communities of Shijingshan, Beijing.Methods:This was a cross-sectional study. Questionnaires, blood biochemical examinations, and periodontal indexes were conducted in elderly people (35 to 84 years old) in four communities of Shijingshan, Beijing between May and July 2005. Non-diabetic patients with fasting blood glucose<6.1 mmol/L, postprandial blood glucose<7.8 mmol/L, and ≥ 10 remaining teeth were included. Patients with diabetes, fasting blood glucose ≥6.1 mmol/L or postprandial blood glucose ≥7.8 mmol/L, and total residual teeth less than 10 were excluded. A total of 362 study subjects met the inclusion criteria. The survey subjects were selected by convenient sampling method. The mean full-mouth probing depth (PD), bleeding index (BI), attachment loss (AL), and plaque index (PLI), as well as PD≥4 mm% (the number of sites with PD≥4 mm as a percentage of the total number of sites in full mouth), PD≥5 mm%, PD≥6 mm%, AL≥3 mm%, AL≥4 mm%, AL≥5 mm% and AL≥6 mm% were used for the analysis. Serum creatinine values was used to calculate GFR. GFR≥90 ml/(min·1.73 m 2) was defined as normal group and GFR<90 ml/(min·1.73 m 2) was defined as reduced group. Univariate analysis was conducted between two groups. Multivariate regression analysis was performed with GFR as dependent variable and adjusted for risk factors such as age, sex, smoking, waist-hip ratio and physical activity. Results:There were 164 subjects in the normal GFR group (45.3%) and 198 in the reduced GFR group (54.7%). Percentage of males in the reduced GFR group, 118 in total, accounting for 59.6%, were significantly higher than in the normal GFR group (73, 44.5%)( P=0.004). The median of age, uric acid, triglyceride, and waist-to-hip ratio (65 years, 323 mmol/L, 1.73 mmol/L, 0.90) were significantly higher in the reduced GFR group than in the normal GFR group (54 years, 277 mmol/L, 1.45 mmol/L, 0.88) ( P<0.05). The median of PD mean, AL mean, BI mean, PD≥4 mm%, AL≥3 mm%, and AL≥4 mm% in the reduced GFR group were 2.80 mm, 2.52 mm, 2.06, 20.4%, 46.5%, and 30.4%, respectively, which were significantly higher than those in the GFR normal group (2.60 mm, 2.37 mm, 1.93, 16.6%, 42.9%, 28.9%) ( P<0.05). After adjusting for confounding factors such as age, gender, smoking, waist-to-hip ratio and physical activity, the results of logistic regression analysis showed that PD mean, AL mean, PD≥4 mm%, PD≥5 mm%, PD≥6 mm%, AL≥3 mm% and AL≥4 mm% of clinical periodontal indexes were significantly correlated with reduced GFR in this population ( OR values were 1.765, 1.879, 1.430, 1.713, 1.771, 1.428, 1.445, respectively, P<0.05). Conclusions:In the non-diabetic elderly population in communities of Shijingshan, Beijing, clinical periodontal indexes reflecting the degree of periodontal tissue destruction were associated with a decreased level of GFR.

Objective:To compare the proliferative and periodontal specific differentiation abilities of induced pluripotent stem cells (iPSCs) at different passages,and to investigate whether long term culturing would have a negative influence on their proliferation and specific differentiation capacity,thus providing a theoretical basis for further in-depth research on periodontal regeneration and the possible clinical applications of iPSCs.Methods:IPSCs derived from human gingival fibroblasts at passages 5,10,15 and 20 were recovered and cultured in vitro.Their morphology and proliferation rates were observed respectively.We further induced the iPSCs at different passages toward periodontal tissue under the treatment of growth/differentiation factor-5 (GDF-5) for 14 days through the EB routine,then compared the periodontal differentiation propensities between the different passages of iPSCs by detecting their calcified nodules formation by Alizarin red staining and assaying their relative periodontal tissue related marker expressions by qRT-PCR and immunofluorescence staining,including bone related markers:osteocalcin (OCN),bone sialoprotein (BSP);periodontal ligament related markers:periostin,vimentin;and cementum related markers:cementum attachment protein (CAP),cementum protein 1 (CEMP1).The untreated spontaneous differentiation groups were set as negative controls respectively.Results:iPSCs at different passages all showed a high proliferative capacity when cultured in vitro and turned into a spindlelike shape similar to fibroblasts upon periodontal specific differentiation.All iPSCs formed typical calcified nodules upon GDF-5 induction by Alizarin red staining in comparison to their untreated controls.The relative calcium deposition at all passages had been significantly upgraded under the treatment of GDF-5 (P5:t =2.125,P =0.003;P10:t =2.246,P =0.021;P15:t =3.754,P =0.004;P20:t =3.933,P =0.002),but no significant difference in their calcium deposition were detected within passages 5,10,15 and 20 (periodontal differentiation:F =2.365,P =0.109;spontaneously differentiation:F =2.901,P =0.067).Periodontal tissue related marker expressions of iPSCs at all passages had also been significandy upgraded under the treatment of GDF-5 (P ＜ 0.05),but still,no significant difference in their expression levels of periodontal tissue related proteins were detected within passages (BSP:F =0.926 7,P=0.450;vimentin:F=0.917 1,P=0.455;CEMP1:F=2.129,P=0.1367).Conclusion:Our results preliminarily confirmed that long term culturing won't influence the proliferation capacity and periodontal specific differentiation propensity of iPSCs,as they can still proliferate and differentiate toward periodontal cells with high efficiency upon growth factor induction after continuous passaging.Therefore,iPSCs could be recognized as a promising cell source for future possible application in periodontal tissue regeneration.

Medical diciplines have been gradually differentiated and specialized during its developement, and problems due to deep specialization have been increasingly apparent. Its performance is as follows: dental specialists tends to focus on a certain narrow area and ignore neither the patients as a whole existence nor the role of the environmental factors. In this article, the author tries to show the holistic integrative medicine (HIM) from the point of view of periodontal specialty. In fact, the pathogenesis, the differential diagnosis and the treatment of periodontal diseases along with the role of preventive dentistry and basic medicine for periodontology must be considered as a whole using the philosophy of HIM. The future development of periodontal specialty should absorb the achievements of other medical and dental diciplines. Periodontist should pay more attention to HIM. The author also gives some thoughts and suggestions on how to practice HIM in the field of periodontics.

Objective:To evaluate the effects of Er,Cr:YSGG laser on the root surface of periodontally involved teeth and healthy teeth,concerning the microstructure and the roughness.Methods:Eight freshly extracted teeth due to severe periodontitis and eight freshly extracted teeth due to orthodontic rea-sons or being third molar were chosen in this study.The root surface of each tooth was divided into four areas,and received four treatment methods:no treatment (control group );root planing with Gracey scaler for 30 seconds;irradiation by the lower power Er,Cr:YSGG laser;irradiation by the higher power Er,Cr:YSGG laser.Four periodontally involved teeth and four healthy teeth were used for the evaluation of microstructure using scanning electron microscope (SEM).The other four periodontitis teeth and four healthy teeth were used for the evaluation of roughness (Ra value )using 3 D profiler.Results:Smear layer was found on the teeth scaled by Gracey scaler,while the teeth irradiated by Er,Cr:YSGG laser demonstrated a melting surface with less smear layer.In the periodontitis teeth irradiated by the higher power,opening dentinal tubules could be observed.For the periodontally involved teeth,the Ra values of groups 1 to 4 were (237.4 ±20.0)nm,(1 35.7 ±1 1 .9)nm (P=0.01 ),(463.6 ±49.3)nm (P<0.001 )and (486.0 ±59.0)nm (P<0.001 )respectively.For the healthy teeth,the Ra values of groups 1 to 4 were (1 91 .4 ±44.5)nm,(1 31 .6 ±21 .5)nm (P=0.482),(463.7 ±34.6)nm (P<0.001 )and (470.3 ±1 21 .3)nm (P<0.001 )respectively.Conclusion:Er,Cr:YSGG laser can affect the microstructure of the cementum of the periodontitis teeth and healthy teeth.Irradiation by the Er,Cr:YSGG laser resulted in a melting surface with less smear layer and increased the roughness in the surface of root.

Objective:To analyze the plaque staining image by using image analysis software,to verify the maneuverability,practicability and repeatability of this technique,and to evaluate the influence of different plaque stains.Methods:In the study,30 volunteers were enrolled from the new dental students of Peking University Health Science Center in accordance with the inclusion criteria.The digital images of the anterior teeth were acquired after plaque stained according to filming standardization.The image analysis was performed using Image Pro Plus 7.0,and the Quigley-Hein plaque indexes of the anterior teeth were evaluated.Results:The plaque stain area percentage and the corresponding dental plaque in-dex were highly correlated,and the Spearman correlation coefficient was 0.776 (P<0.01 ).Intraclass correlation coefficients of the tooth area and plaque area which two researchers used the software to calcu-late were 0.956 and 0.930 (P<0.01).The Bland-Altman analysis chart showed only a few spots outside the 95%consistency boundaries.The different plaque stains image analysis results showed that the diffe-rence of the tooth area measurements was not significant,while the difference of the plaque area measure-ments significant (P<0.01).Conclusion:This method is easy in operation and control,highly related to the calculated percentage of plaque area and traditional plaque index,and has good reproducibility.The different plaque staining method has little effect on image segmentation results.The sensitive plaque stain for image analysis is suggested.