Research Progress on the Immunomodulatory Effect of Mesenchymal Stem Cells on Chronic Periodontitis

Periodontal disease is an inflammatory and destructive disease of periodontal support tissue caused by microorganisms in dental plaque. During the development of periodontal disease, host immune regulation plays an important role, and unnecessary excessive immune regulation often exacerbates the course of chronic periodontal disease. Mesenchymal stem cells (MSCs) are adult stem cells with self replication ability and multi-directional differentiation potential. Many studies have found that MSCs have strong immunosuppressive effects on both adaptive and innate immunity. In recent years, literature has reported that MSCs are involved in the immune regulatory effect of chronic periodontal disease, inhibiting its inflammatory response and alveolar bone resorption, but the specific regulatory mechanism has not been elucidated. This article reviews the current research status of the immune regulatory effects of MSCs on chronic periodontitis.

Nonsurgical periodontal-therapy improves glycosylated hemoglobin levels in pre-diabetic patients with chronic periodontitis

AIM To evaluate the effect of nonsurgical periodontal therapy on glycosylated haemoglobin levels in pre-diabetic patients with chronic periodontitis(CHP).METHODS Sixty pre-diabetic patients with CHP were selected and equally allocated to case and control group. All subjects were evaluated at base line for periodontal parameters(plaque index, oral hygiene index, modified gingival index, probing pocket depth, clinical attachment level) and systemic parameters [glycosylated hemoglobin(HbA1c), fasting lipid profile, and fasting blood glucose]. The case group received non-surgical periodontal therapy. Subjects were re-evaluated for periodontal and systemic parameters after three months.RESULTS Both groups were comparable at baseline. Three months after non surgical periodontal therapy(NSPT), there was significant improvement in periodontal parameters in case group. The mean difference in systemic parameters like HbA1c and fasting plasma glucose from baseline to fourth month for case group was 0.22 ± 0.11 and 3.90 ± 8.48 respectively and control group was-0.056 ± 0.10 and-1.66 ± 6.04 respectively, which was significant between case and control group(P < 0.05). In the case group there was a significant decrease in HbA1c from baseline to three months following NSPT(P < 0.05).CONCLUSION This study showed that periodontal inflammation could affect the glycemic control in otherwise systemically healthy individuals. Periodontal therapy improved periodontal health status and decreased glycosylated haemoglobin levels, thus reducing the probability of occurrence of inflammation induced prediabetes in patients with CHP.

Treatment effects and periodontal status of chronic periodontitis after routine Er:YAG laser-assisted therapy

BACKGROUND Routine preclinical interventions for patients with chronic periodontitis such as supragingival cleaning and subgingival curettage,establishing a balanced occlusal relationship,and irrigation with 3%hydrogen peroxide can relieve the symptoms to some extent.However,there is room for improvement in the overall effect.For example,Er:YAG lasers can quickly increase the temperature of the irradiated tissue,effectively eliminate dental plaque and calculus,reduce periodontal pockets,adjust periodontal microecology,and reduce the gingival sulcus.The content of factors in the liquid,and then achieve the purpose of treatment.AIM The aim was evaluate the effect of Er:YAG laser-assisted routine therapy on the periodontal status in chronic periodontitis.METHODS Between October 2018 and January 2020,106 patients with chronic periodontitis in our hospital were randomly assigned to either the study or control group,with 53 patients in each group.The control group underwent routine therapy,and the study group underwent Er:YAG laser therapy in addition to routine therapy.We evaluated the treatment outcome in both groups.Periodontal status was determined by clinical attachment loss(CAL),gingival index(GI),periodontal probing depth(PD),dental plaque index(PLI),and sulcular bleeding index(SBI),inflammatory factors in the gingival crevicular fluid,tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-8],and colony forming units(CFUs).RESULTS Total effectiveness in the study group(94.34%)was higher than that in the control group(79.25%,P<0.05).The clinical parameters in the study group(PD,5.28±1.08 mm;CAL,4.81±0.79 mm;SBI,3.37±0.59;GI,1.38±0.40;PLI,2.05±0.65)were not significantly different from those in the control group(PD,5.51±1.14 mm;CAL,5.09±0.83 mm;SBI,3.51±0.62;GI,(1.41±0.37;PLI,1.98±0.70)before treatment(P>0.05).However,after treatment,the parameters in the study group(PD,2.97±0.38 mm;CAL,2.71±0.64 mm;SBI,2.07±0.32;GI,0.51±0.11;PLI,1.29±0.34)were lower than those in the control group(PD,3.71±0.42 mm;CAL,3.60±0.71 mm;SBI,2.80±0.44;GI,0.78±0.23;PLI,1.70±0.51)(P<0.05).Differences in crevicular TNF-α,IL-6,and IL-8 levels in the study(TNF-α,7.82±3.43 ng/mL;IL-6,11.67±2.59 ng/mL;IL-8,12.12±3.19 pg/mL)and control groups(TNF-α,9.06±3.89 ng/ml,IL-6,12.13±2.97 ng/mL,IL-8,10.99±3.30 pg/mL)before therapy(P>0.05)were not significant.Following treatment,the parameters were significantly lower in the study group(TNF-α,2.04±0.89 ng/mL;IL-6,4.60±1.26 ng/mL;IL-8,3.15±1.08 pg/mL)than in the control group(TNF-α,3.11±1.07 ng/mL;IL-6,6.25±1.41 ng/mL;IL-8,4.64±1.23 pg/mL,P<0.05).The difference in the CFU of the study group[(367.91±74.32)×104/mL and control group(371.09±80.25)×104/mL]before therapy was not significant(P>0.05).The CFU decreased in both groups following therapy,however,the CFU values were lower in the study group[(36.09±15.26)×104/mL]than in the control group[(45.89±18.08)×104/mL](P<0.05).CONCLUSION Combining Er:YAG lasers with routine measures significantly improved the overall periodontal therapy outcomes by improving periodontal status and reducing oral levels of inflammatory factors and CFUs.

Development and validation of a self-management ability questionnaire for patients with chronic periodontitis

Objective: This study aimed to develop and validate a self-management ability questionnaire for patients with chronic periodontitis.Methods: A questionnaire was developed through theoretical research,literature review,semistructured interview,and expert consultation.A total of 231 patients with chronic periodontitis from the Department of Periodontics in the Stomatological Hospital of Tianjin Medical University were recruited by convenient sampling.Validity and reliability were analyzed.Results: The questionnaire consisted of 24 items.Exploratory factor analysis identified three principal factors,which explained 66.949% of the total variance.The item-level content validity was between 0.800 and 1.000,and the scale-level content validity was 0.969.The coefficient of correlation between the gold standard and the whole questionnaire was 0.869.Cronbach's α of the whole questionnaire was 0.931,and the test-retest reliability coefficient was 0.825.Conclusion: The questionnaire developed in this study satisfies the measurement standard and has good reliability and validity.It is useful for clinical work to measure self-management among patients with chronic periodontitis.

Research progress of pattern recognition receptors and chronic periodontitis

Pattern recognition receptor(PRR)is a kind of sensor which is mainly expressed on the surface of innate immune cells.It can recognize pathogen related molecular patterns(PAMPs)or damage related molecular patterns(DAMPs).The innate immune system uses pattern recognition receptors to recognize pathogenic microorganisms in periodontal tissues and transmit signals to downstream pathways in time,thus triggering immune responses and then eliminating them.PRR has many family members,including toll like receptor family(TLRs),C-type lectin receptor family(CLRs),retinoic acid induced gene I(RIG-I)like receptor family(RLRs)and nucleotide binding oligomer domain(NOD)like receptor family(NLRs).Among them,RLRs are cytoplasmic receptors that recognize dsRNA from RNA viruses and have little association with chronic periodontitis.In this paper,the classification and structure of TLRs,CLRs,NLRs and the role of signal transduction pathway in chronic periodontitis are reviewed.In order to enrich the pathogenesis of periodontitis,provide new ideas for the treatment and prevention of chronic periodontitis.

Five-year outcomes of immediate implant placement for mandibular molars with and without chronic apical periodontitis:A retrospective study

BACKGROUND Most physicians consider molars with chronic apical periodontitis(CAP)lesions as contraindications for immediate implant placement.At the patient’s request,we perform immediate implant placement of the mandibular molars with CAP in clinical practice.AIM To retrospectively analyze and compare the 5-year outcomes of immediate implant placement of the mandibular molars with CAP and those without obvious inflammation.METHODS The clinical data of patients with immediate implant placement of the mandibular molars in the Department of Oral and Maxillofacial Surgery,the Affiliated Hospital of Qingdao University,from June 2015 to June 2017 were collected.The patients were divided into CAP(n=52)and no-CAP(n=45)groups.Changes in bone mineral density and bone mass around implants were analyzed 5 years after implant restoration.RESULTS At 5 years after implantation,the peri-implant bone mineral density was 528.2±78.8 Hounsfield unit(HU)in the CAP group and 562.6±82.9 HU in the no-CAP group(P=0.126).Marginal bone resorption around implants did not differ significantly between the two groups,including buccal(P=0.268)or lingual(P=0.526)resorption in the vertical direction or buccal(P=0.428)or lingual(P=0.560)resorption in the horizontal direction.Changes in the peri-implant jump space did not differ significantly between the two groups,including the buccal(P=0.247)or lingual(P=0.604)space in the vertical direction or buccal(P=0.527)or lingual(P=0.707)space in the horizontal direction.The gray value of cone-beam computed tomography measured using Image J software can reflect the bone mineral density.In the CAP area,the gray values of the bone tissue immediately and 5 years after implant placement differed significantly from those of the surrounding bone tissue(P<0.01).CONCLUSION The results of this study suggest that immediate implant placement of the mandibular molars with CAP can achieve satisfactory 5-year clinical results,without significant differences in the complications,survival rate,or bone tissue condition from the no-CAP mandibular molars.

Role of salivary matrix metalloproteinase-8 （MMP-8） in chronic periodontitis diagnosis

Periodontitis is an inflammatory disease of the periodontium. Any imbalance between the matrix metalloproteinases （MMPs） secreted by neutrophils and tissue inhibitors initiates the destruction of collagen in gum tissue, leading to chronic periodontitis. This study aimed to correlate salivary levels of MMP-8 and periodontal parameters of chronic periodontitis to establish MMP-8 as a noninvasive marker for the early diagnosis of chronic periodontitis. The study involved 40 subjects visiting the periodontic OPD of Dr. Ziauddin Ahmad Dental College and Hospital, located in Aligarh, U.P., India, from 2011 to 2012. The subjects were divided into two groups： group I consisted of 20 periodontally healthy subjects （controls） while group II consisted of 20 patients with chronic periodontitis. Chronic periodontitis was assessed on the basis of several periodontal parameters, including pocket probing depth （PPD）, clinical attachment level （CAL）, gingival index （GI）, and plaque index （PI）. Around 3 ml of unstimulated and whole expectorated saliva was collected for MMP-8 estimation by ELISA using Quantikine human total MMP-8 immunoassay kits. Data were analyzed using STATISTICA （Windows version 6） software. Salivary MMP-8 levels of groups I and II were 190.91 ± 143.89 ng/ml and 348.26± 202.1 ng/ml, respectively. The MMP-8 levels and periodontal status （PPD, CAL, GI, and PI） of groups I and II showed positive and significant correlations （for PPD, r = 0.63, P 〈 0.001; for CAL, r = 0.54, P 〈 0.001; for GI, r = 0.49, P 〈 0.001; and for PI, r = 0.63, P 〈 0.001）. The results of this study demonstrate elevated concentrations of MMP-8 in individuals with chronic periodontitis.

Correlation of estrogen receptor alpha gene polymorphisms and bone mineral density in Chinese women with chronic periodontitis

Background Periodontitis and osteoporosis are one of the frequently encountered diseases in post-menopausal women. Estrogen receptors （ERs） regulated bone metabolism. To investigate the possible effect of ER-elpha （a） gene polymorphisms on bone mineral density （BMD） in pre- and post-menopausal Chinese women with chronic periodontitis （CP）, we provided sufficient quantitative information concerning the correlation between ER gene polymorphisms and BMD in periodontitis. Methods Sixty-five post-menopausal and eighty pre-menopausal CP women, and sixty post-menopausal healthy individuals were recruited in this study. Genomic DNA was extracted from oral mucosa swab sample of each subject by the Chelex-100 method. Determination of the ER-a polymorphisms was performed by polymerese chain reaction-restriction fragment length polymorphism （PCR-RFLP） technique with Xbal and Pvull enzyme. The index for periodontal examination includes clinical attachment loss （CAL） and probing pocket depth （PPD）. BMD was measured by dual-energy X-ray absorptiometry （DEXA）. Results There were no significant differences between the ER-α genotypes of Pvull and Xbal and BMD in post-menopausal and pre-menopausal CP patients, respectively （P 〉0.05）. However, there was association between pre- and post-menopausal CP patients at BMD of lumbar spine L2-L4 （P=0.027） and Ward＇s BMD （P=0.004）. Furthermore, the post-menopausal CP women who carried Pvull TT genotype presented significantly lower Ward＇s BMD than the pre-menopausal CP women （P=-0.007）, meanwhile, the post-menopausal CP women who carried Xbal AA genotype presented significantly lower spine L2-L4 BMD than the pre-menopausal CP women （P=0.003）. Conclusions ER-α gene polymorphisms may be a susceptible indicator for BMD variation of lumbar spine L2-L4 and Ward in Chinese pre- and post-menopausal women patients with CP.

Effect of Plaque Control on Chronic Periodontitis in Psychiatric Patients with Long-term Hospitalization

Objective:To study the effect of plaque control on chronic periodontitis in psychiatric patients.Methods:116 psychiatric patients with chronic periodontitis in our hospital from March 2016 to April 2019 were selected as the research objects.All the patients were treated with ultrasonic curettage combined with minocycline hydrochloride ointment,and the patients were supervised to brush their teeth correctly every day.The clinical treatment effect,detection of periodontal pathogens in subgingival plaque and gingival crevices were observed after treatment.The levels of tumor necrosis facto-α(TNF-α),hypersensitive C-reactive protein(hs CRP)and interleukin-6(IL-6)in the fluid were measured,SBI were observed and recorded.Results:After the treatment,the levels of PG,Aa,Fn,Tf,Pi,Td,were significantly decreased,and the difference was statistically significant(P<0.05).After treatment,the inflammatory factor index decreased significantly,and the difference was statistically significant(P<0.05).After treatment,PD,AL and SBI indexes decreased significantly,and the difference was statistically significant(P<0.05).Conclusion:Plaque control has a significant effect on psychosis patients with chronic periodontitis.It can improve the pathogenic bacteria in subgingival plaque and reduce the expression of inflammatory factors in the gingival crevicular fluid.

Correlation of Levels of Oncostatin M Cytokine in Crevicular Fluid and Serum in Periodontal Disease

Aim The aim of this study was to measure the level of Oncostatin M （OSM） a gp130 cytokine in the gingival crevicular fluid （GCF） and serum of chronic periodontitis patients and to find any correlation between them before and after periodontal therapy （scaling and root planing,SRP）. Methodology 60 subjects （age 25-50 years） were enrolled into three groups （n=20 per group）,group Ⅰ （healthy）,group Ⅱ （gingivitis） and group III （chronic periodontitis）. Group Ⅲ subjects were followed for 6-8 weeks after the initial periodontal therapy （SRP） as the group Ⅳ （after periodontal therapy）. Clinical parameters were assessed as gingival index （GI）,probing depth （PD）,clinical attachment level （CAL）,and radiographic evidence of bone loss. GCF and serum levels of OSM were measured by using Enzyme Linked Immunosorbent Assay （ELISA）. Results It was found that mean OSM levels had been elevated in both the GCF and serum of chronic periodontitis subjects （726.65 ± 283.56 and 65.59 ± 12.37 pg·mL-1,res-pectively） and these levels were decreased proportionally after the periodontal therapy （95.50 ± 38.85 and 39.98 ± 16.69 pg·mL-1 respectively）. However,OSM was detected in GCF of healthy subjects （66.15 ± 28.10 pg·mL-1） and gingivitis-suffering subjects （128.33 ± 22.96 pg·mL-1） and was found as below the detectable limit （≈0.0 pg·mL-1） in the serum of same subjects. Significant correlation has been found between clinical parameters and GCF-serum levels of OSM. Conclusion Increased OSM level both in the GCF and serum,and the decreased levels after initial periodontal therapy （SRP） may suggest a use as an inflammatory bio-marker in the periodontal disease.

Study on the mechanism of Porphyromonas gingivalis pili mediated ather osclerosis

Chronic periodontitis is the most common infectious periodontal disease caused by plaque biofilm.Pili is an important bacterial component of Porphyromonas gingivalis.Epidemiological studies have shown that chronic periodontitis can increase the risk of cardiovascular disease,and atherosclerosis is the pathological basis of cardiovascular disease.This article will summarize the mechanism of Porphyromonas gingivalis pili protein mediated chronic periodontitis and atherosclerosis,in order to expand new ideas of disease prevention and treatment.

Pulp revascularization on an adult mandibular right second premolar:A case report

BACKGROUND Pulp revascularization has become a new method for the treatment of periapical diseases in young permanent teeth in recent years.Through root canal flushing and disinfection,avoiding mechanical preparation,guiding apical stem cells into the root canal and promoting the continuous development of tooth roots,it has achieved good clinical curative effects.But in adult patients with chronic periapical periodontitis with immature roots and open apices,apical barrier technology is often used to treat these teeth.CASE SUMMARY Pulp revascularization of a 26-year-old patient's tooth was performed using cefaclor instead of minocycline and iRoot BP instead of mineral trioxide aggregate as intracanal medication.The case was followed up for 36 mo.Observations showed evidence of regression of clinical signs and symptoms,resolution of apical periodontitis and no discolouration of affected teeth.CONCLUSION For adult patients with chronic periapical periodontitis with immature roots and open apices,pulp revascularisation showed favourable results in treating these teeth.

An investigation of immunocompetence substances in normal gingival and periodontitis tissue

To investigate the effects of nitric oxide (NO), endothelin (ET), substance P (SP) and calcitonin gene-related peptide (CGRP) immunocompetence substances and their relationship to chronic periodontitis Methods Immunohistochemical aod histochemical staining methods were used to detect the expression of the NO synthase (NOS), ET, SP and CGRP levels in 20 patients with chronic periodontitis and 20 healthy subjects as control Results Quantitative analysis by Quantimat 970 showed that NOS and ET in periodontitis tissue increased significantly ( P <0 01), particularly the content of ET in comparison with healthy subjects The intergroup expression of SP and CGRP showed no remarkable changes Conclusion Our results demonstrate that the level of NOS and ET were significantly increased in periodontitic tissue, which may diminish the blood supply and influence the periodontal tissue causing tissue damage Our study suggests that immunocompetence substances NO and ET are closely associated with periodontitis and may play an important role in the disease

Detection of periodontal pathogens in the patients with aortic aneurysm

Background The occurrence and development of aortic aneurysm （AA） are associated with infection.Some researchers have detected the DNA of periodontal pathogens in AA samples in certain populations.However,it has not been done in Chinese population.The objective of this study was to evaluate the prevalence of periodontal pathogens in oral tissue samples and aneurysm samples of AA patients.Methods Eighty-nine subjects with AA and 59 subjects without AA were examined.Periodontal clinical parameters were evaluated.Unstimulated saliva and subgingival plaque somples were collected from all subjects.Twenty-six dissected AA samples were obtained.Evidence of eight periodontal pathogens including Porphyromonas gingivalis （Pg）,Actinobacillus actinomycetemcomitans （Aa）,Prevotella intermedia （Pi）,Tannerella forsythensis （Tf）,Treponema denticola （Td）,Campylobacter rectus （Cr）,Fusobacterium nucleatum （Fn）,and Prevotella nigrescens （Pn） was ascertained in all samples by 16S rRNA-based polymerase chain reaction （PCR） assay.Results The periodontal indexes including plaque index （PLI）,probing depth （PD）,bleeding index （BI）,and clinical attachment loss （CAL）,of the six Ramfjord index teeth were significantly higher in the AA group than those in the control group （P ＜0.01）.Eight periodontal pathogens in subgingival plaque samples were more frequently detected in the AA group than in control group.The difference in prevalence between the groups was significant for six （out of eight） periodontal pathogens assayed （Pg,Pi,Fn,Pn,Tf,and Td,P ＜0.01）.Additionally,all eight periodontal pathogens were more frequently detected in saliva samples of the AA group than in those of the control group,again with six （out of eight） （Pg,Pi,Fn,Cr,Tf,and Td） displaying significant differences in prevalence between the two groups （P ＜0.01）.Out of 26 aneurysm samples examined,Pg,Pi,Fn,Crand Tfwere detected in 6 （23.1％）,2 （7.7％）,3 （11.5％）,1 （3.8％）,2 （7.7％）,respectively,and Aa,Pn,and Td were not detected in dissected aneurysm samples.Conclusion Results of this study suggested that periodontal infection is associated with the occurrence of AA.

Association of periodontal disease with glycemic control in patients with type 2 diabetes in Indian population

This study aims to investigate the link between glycated hemoglobin and diabetic complications with chronic periodontitis. A total of 207 patients with type 2 diabetes and chronic periodontitis （CP） were divided according to tertiles of mean PISA （periodontal inflamed surface area） scores as low, middle and high PISA groups. Simultaneously a group of 67 periodontally healthy individuals （PH） was recruited. Periodontal examinations, including full-mouth assessment of probing depths （PPD）, bleeding on probing, clinical attachment level and plaque scores were determined. Blood analyses were carried out for glycated hemoglobin （HbA1c）, fasting plasma glucose （FPG）, 2 h post parandial glucose （PPG）. Individuals in PH group had significantly better glycemic control than CP group. Upon one-way analysis of variance, subjects with increased PISA had significantly higher HbA1c levels, retinopathy and nephropathy （P 〈 0.05）. After controlling for age, gender, body mass index （BMI）, socioeconomic status （SES）, family history of diabetes and periodontitis, duration of diabetes, the mean PISA in mm^2, PPD 4-6 mm （%） and PPD ≥7 mm （%） emerged as significant predictors for elevated HbAlc in regression model （P 〈 0.05）. Logistic regression analysis revealed that PISA was associated with higher risk of having retinopathy and neuropathy （odds ratio）. In our study, the association between glycemic control and diabetic complications with periodontitis was observed.

Short-term microbiological effects of scaling and root planing and essential-oils mouthwash in Chinese adults

Objective: To assess the short-term effect of scaling and root planing (SRP) and essential-oils mouthwash on the levels of specific bacteria in Chinese adults. Methods: Fifty Chinese adults with chronic periodontitis were randomly assigned to full-mouth SRP or a 7-d essential-oils mouthwash regimen. In addition, 22 periodontally healthy adults used essential-oils mouthwash for 7 d. Clinical examination and plaque/saliva sampling were performed at baseline and on Day 7. Quantitative real-time polymerase chain reaction (PCR) was used to measure Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and total bacterial loads in saliva, supra- and sub-gingival plaque samples. Results: The detection frequencies of four tested species remained unchanged after either treatment. However, the bacterial loads of Fn, Pg, and Pi were significantly reduced by SRP; the mean reduction of bacterial counts in saliva ranged from 52.2% to 62.5% (p<0.01), in supragingival plaque from 68.2% to 81.0% (p<0.05), and in subgingival plaque from 67.9% to 93.0% (p<0.01). Total bacterial loads were reduced after SRP in supra- and sub-gingival plaque (p<0.05). Essential-oils mouthwash reduced Fn levels in supragingival plaque by a mean of 53.2%, and reduced total bacterial loads in supra- and sub-gingival plaque (p<0.01). In subgingival plaque from periodontal patients, Pg and Pi reductions were high after SRP compared to essential-oils mouthwash (93.0% vs. 37.7% and 87.0% vs. 21.0%, p<0.05). No significant bacterial reduction was observed in periodontally healthy subjects using essential-oils mouthwash. Conclusions: SRP and essential-oils mouthwash both have an impact on saliva and gingival plaque flora in Chinese periodontitis patients in 7 d, with greater microbiological improvement by SRP.