Bacteria ; genetics ; pathogenicity ; Dental Research ; Genomic Islands ; Periodontitis ; microbiology

OBJECTIVETo make qualitative and quantitative analysis of Archaea in subgingival plaque sample and to investigate the relationship between periodontal disease and Archaea.

METHODSSubgingival plaque was collected from 23 patients with aggressive periodontitis, 29 with chronic periodontitis, 35 with plaque-induced gingivitis and 38 healthy controls. Qualitative and quantitative analysis of methanogenic archaea was performed by amplification of the 16S rRNA genes in the DNA extracted from the plaque samples.

RESULTSArchaea were found in 65% of aggressive periodontitis patients, 72% of chronic periodontitis, 26% of gingivitis and zero of healthy subjects. Quantitative analysis showed the average abundance of archaeal 16S rRNA gene in Archaea-positive patients was different among the three groups. The average 16S rRNA gene copy number from per microg wet plaque was 6.66 x 10(6) in aggressive periodontitis sufferers, 4.47 x 10(6) in chronic periodontitis and 1.78 x 10(6) in gingivitis groups. The prevalence of Archaea and the average Archaea 16S rRNA gene numbers in periodontitis groups were higher than those in gingivitis group (P < 0.05).

CONCLUSIONSThis suggests that Archaea may be implicated as causative agents for periodontitis.

Aggressive Periodontitis ; microbiology ; Archaea ; classification ; genetics ; isolation & purification ; Case-Control Studies ; Chronic Periodontitis ; microbiology ; DNA, Bacterial ; genetics ; Dental Plaque ; microbiology ; Humans ; Periodontal Diseases ; microbiology ; RNA, Ribosomal, 16S ; genetics

OBJECTIVETo investigate the prevalence of Actinobacillus actinomycetemcomitans (Aa) in whole saliva of different types of periodontitis and compare the detections of Aa between saliva and pooled subgingival plaque sample, and analyze the relationship between Aa and clinical conditions.

METHODSUnstimulated whole saliva samples and pooled subgingival samples were collected from 50 aggressive periodontitis (AgP) patients, 48 chronic periodontitis (CP) patients and 25 subjects with no periodontitis, and Aa was detected in these samples by PCR method.

RESULTSThe prevalence of Aa in whole saliva of AgP patients was significantly higher than in subjects with no periodontitis (32% vs. 4%, P<0.01) and CP patients (32% vs. 15%, P<0.05). Aa was also more frequently detected in whole saliva sample than in pooled subgingival sample of AgP patients (32% vs. 16%, P<0.05). Subjects younger than 30 years old were more likely to present Aa in whole saliva ( OR = 3.23, P<0.05) and percentage of sites with bleeding index (BI) > or = 3 over 70% was a risk indicator for the presence of Aa in whole saliva

CONCLUSIONSThe detection of Aa in whole saliva sample of AgP patients was more frequent than in pooled subgingival plaque samples, and also more frequent than in CP patients and subjects with no periodontitis, which suggest that Aa may participate in the initiation and progression of aggressive periodontitis.

Adult ; Aggregatibacter actinomycetemcomitans ; isolation & purification ; Chronic Periodontitis ; microbiology ; Dental Plaque ; microbiology ; Female ; Humans ; Male ; Middle Aged ; Periodontitis ; microbiology ; Saliva ; microbiology ; Young Adult

OBJECTIVEThe study is to investigate the microbial composition of interdental and subgingival plaques of periodontitis patients with or without malodor, to explore the relationships between periodontitis and oral malodor.

METHODS20 patients of periodontitis with malodor were chosen from 210 patients of periodontitis, and the clinical parameter of plaque index (PLI), gingival bleeding index (GBI) and probing depth (PD) were measured and compared with the control group which had periodontal disease without malodor. During the experiment, the interdental and subgingival microbial samples in both groups were collected and sent to anaerobic culture for 48 hrs, then the total CFU/ml of each sample were counted, and each type of bacteria was separated and identified. All of the data were analyzed by using the statistical software SPSS 10.0.

RESULTS(1) There were no satistical differences on PLI, GBI, PD between experimental group and control group. (2) The percents of leptospira in both interdental and subgingival plaques of test group were significantly higher than that of the control group (P < 0.01). (3) Either the interdental or in subgingival plaques, the count results of CFU/ml were similar in both groups (P > 0.05). (4) The proportions of malodor producing anaerobic bacteria in interdental gingival plaque, such as P. gingivalis and Veillonelia, were singnificantly different between test group and control group.

CONCLUSIONThe proportions of VSC's producing anaerobic bacteria in interdental gingival plaque may be play the significant roles in oral malodor. Further studies should be taken to elucidate the relationship between malodor and periodontitis.

Bacteria, Anaerobic ; classification ; Dental Plaque ; microbiology ; pathology ; Dental Plaque Index ; Gingiva ; microbiology ; pathology ; Halitosis ; microbiology ; Humans ; Odorants ; Periodontitis ; microbiology ; pathology

The reduction of nitrate to nitrite by the oral microbiota has been proposed to be important for oral health and results in nitric oxide formation that can improve cardiometabolic conditions. Studies of bacterial composition in subgingival plaque suggest that nitrate-reducing bacteria are associated with periodontal health, but the impact of periodontitis on nitrate-reducing capacity (NRC) and, therefore, nitric oxide availability has not been evaluated. The current study aimed to evaluate how periodontitis affects the NRC of the oral microbiota. First, 16S rRNA sequencing data from five different countries were analyzed, revealing that nitrate-reducing bacteria were significantly lower in subgingival plaque of periodontitis patients compared with healthy individuals (P < 0.05 in all five datasets with n = 20-82 samples per dataset). Secondly, subgingival plaque, saliva, and plasma samples were obtained from 42 periodontitis patients before and after periodontal treatment. The oral NRC was determined in vitro by incubating saliva with 8 mmol/L nitrate (a concentration found in saliva after nitrate-rich vegetable intake) and compared with the NRC of 15 healthy individuals. Salivary NRC was found to be diminished in periodontal patients before treatment (P < 0.05) but recovered to healthy levels 90 days post-treatment. Additionally, the subgingival levels of nitrate-reducing bacteria increased after treatment and correlated negatively with periodontitis-associated bacteria (P < 0.01). No significant effect of periodontal treatment on the baseline saliva and plasma nitrate and nitrite levels was found, indicating that differences in the NRC may only be revealed after nitrate intake. Our results suggest that an impaired NRC in periodontitis could limit dietary nitrate-derived nitric oxide levels, and the effect on systemic health should be explored in future studies.
Humans ; Nitrates ; Nitric Oxide ; Nitrites ; RNA, Ribosomal, 16S/genetics* ; Periodontitis/microbiology* ; Bacteria ; Dental Plaque/microbiology* ; Saliva/microbiology* ; Microbiota/genetics*

OBJECTIVETo investigate the distribution of fimA genotype of P. gingivalis in chronic periodontitis patients.

METHODSSubgingival plaque samples were collected from 101 chronic periodontitis patients. P. gingivalis was detected by both culture method and P. gingivalis 16S rRNA PCR. fimA type-specific primer were designed, and the distribution of fimA genotype of P. gingivalis in periodontitis patients were detected by PCR.

RESULTSThe detective ratio of P. gingivalis was 88.1%. Among them, a single fimA genotype was detected in most subgingival plaque samples (65.1%), and the distribution of five fimA genotypes among P. gingivalis positive patients was as follows: type I, 24.7%; type II, 43.8%; type III, 15.7%; type IV, 40.4%; type V, 3.4%; respectively.

CONCLUSIONP. gingivalis with various fimA genotypes were present in subgingival plaque samples from chronic periodontitis patients, and P. gingivalis with type II fimA and IV fimA were more predominant in chronic periodontitis patients, and they may be associated with the development of periodontitis.

Adult ; Chronic Periodontitis ; microbiology ; Dental Plaque ; Female ; Fimbriae Proteins ; genetics ; Genotype ; Humans ; Male ; Periodontitis ; Polymerase Chain Reaction ; Porphyromonas gingivalis ; genetics

OBJECTIVETo examine Porphyromonas gingivalis (Pg) in subgingival plaque of the patients with periodontitis and to find out the rules of Pg colonization after periodontal initial treatment.

METHODSA total of 1620 subgingival plaque samples were collected from 180 subjects including chronic periodontitis (CP) patients (n = 90), and aggressive periodontitis (AgP) patients (n = 90) in different periods of periodontal initial therapy-the baseline, 6 weeks, and 12 weeks after treatment. The following periodontal clinical parameters were recorded with Florida probe at sampled sites: probing depth (PD), clinical attachment loss (CAL), and bleeding on probing (BOP). Quantities of Pg were examined by AmpliFluor endpoint quantitative polymerase chain reaction.

RESULTSAt the 6th week of periodontal initial therapy, there were 61 (22.6%) and 66 (24.4%) Pg increased sites respectively, in which no significant difference was detected (P > 0.05). At baseline of periodontal initial therapy, more severe periodontal clinical parameters of Pg increased sites were observed than those of Pg stationary sites. At the 12th week, however, there were 96 (35.6%) and 18 (6.7%) Pg increased sites respectively, significant difference detected (P < 0.05). At 6th week of periodontal initial therapy, more severe periodontal clinical parameters of Pg increased sites were observed than those of Pg stationary sites.

CONCLUSIONSPg colonization in AgP and CP patients started 6 weeks after periodontal initial therapy, but the recolonization pattern was different between these two groups of patients. Severe periodontitis sites in baseline seemed to place them at risk of Pg colonization after periodontal initial therapy.

Adolescent ; Adult ; Aged ; Aggressive Periodontitis ; microbiology ; therapy ; Chronic Periodontitis ; microbiology ; therapy ; Female ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Porphyromonas gingivalis ; isolation & purification ; Young Adult

OBJECTIVETo study the effect of the left bacteria on the root canal therapy.

METHODS50 single-rooted teeth with chronic apical periodontitis were divided into two groups, one was instrumented with step-back technique and 2.5%NaOCl ultrasonic irrigation for 3 min, then filled with Thermafil. Samples were taken after instrumentation to culture. The other was treated with traditional RCT at three visits.

RESULTSIn 24 months the apical radiolucency were greatly reduced in all cases. There weren't significant relationship among the postoperative pain and the left bacteria, the degree of the obturation or the pre-operative symptoms (P > 0.05).

CONCLUSIONThe effect of left bacteria in root canal filled with Thermafil wasn't observed.

Adolescent ; Adult ; Aged ; Dental Pulp Cavity ; microbiology ; Female ; Humans ; Male ; Middle Aged ; Periapical Periodontitis ; microbiology ; therapy ; Prognosis ; Root Canal Therapy

Adult ; Aged ; Bacteria ; isolation & purification ; Coronary Artery Disease ; microbiology ; DNA, Bacterial ; analysis ; Humans ; Middle Aged ; Periodontitis ; microbiology

Objective: To detect and analyze the characteristics of oral microbiota in species composition, function and metabolism among caries, periodontitis and oral healthy individuals, hunting for the microbiome-derived biomarkers with specificity and sensitivity to estimate the occurrence of these two diseases. Methods: Saliva samples were collected from 10 patients with high caries risk [decayed-missing-filled teeth (DMFT)≥6, HC group] in Department of Endodontics, 10 patients with periodontitis of grade Ⅱ A-Ⅲ C (PG group) in Department of Periodontology and 10 oral healthy individuals (HH group) from School of Stomatology, The Fourth Military Medical University during from March 2022 to June 2022. A baseline examination was conducted on all participants, including their oral conditions of caries and periodontal health. Metagenomic sequencing (Illumina PE150 platform) and liquid chromatography-mass spectrometry were used to detect microorganisms and their metabolites in the samples respectively. The sequencing data were analyzed to obtain the information of microbial taxonomic composition, functional genes and metabolites in each group of samples. The basic oral conditions and saliva samples of subjects in each group were evaluated and collected by the same professional endodontist. Results: There were no significant difference in baseline characteristics such as age and sex among the subjects in each group (P>0.05). DMFT in HC group (9.0±1.7) was significantly higher than that in HH group (0) and PG group (0) (F=243.00, P<0.001). Sequencing data analysis showed that the taxonomic compositions of salivary microbiota in each group were mainly Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria and Fusobacteria at the phylum level, and Streptococcus, Neisseria, Rothia, Prevotella at the genus level. Differential analysis showed that, compared with the HH group, HC group and PG group had significant differences in taxonomic composition (P<0.05), and the most significant among them was Prevotella. At the species level, Prevotella pallens was the most significant change in HC group, and Porphyromonas gingivalis in PG group. Metabolite analysis showed that there were significant differences in metabolites between HC group and PG group. The results showed that, compared with the HH group, the most significant metabolite change was 3-hydroxy-1, 5-diphenylpentan-1-one in HC group (P=0.001) and N1 acetylspermine in PG group (P=0.002) respectively. Compared with the PG group, the metabolite of HC group with the most significant difference is D-glucosamine 6-phosphate (P=0.006). The metabolism gene function analysis showed that, the enrichment of carbohydrate metabolism related genes was highest in HC group, followed with HH group, and it was lowest in PG group. In addition, compared with the HH group, the abundance of functional genes related to glucose metabolism, such as ABC transporter and phosphotransferase system, were significantly decreased in PG group (P<0.05), but significantly increased in HC group (P<0.05). Conclusions: There is a significant correlation between the alternation of carbohydrate metabolism of salivary microbiota with the occurrence of caries and periodontitis. In the future, Prevotella pallens and 3-hydroxy-1, 5-diphenylpentan-1-one may be the potential biomarkers of caries; while Porphyromonas gingivalis and N1 acetylspermine work in the predictions of periodontitis.
Humans ; Saliva/microbiology* ; Dental Caries Susceptibility ; Periodontitis/microbiology* ; Microbiota/genetics* ; Porphyromonas gingivalis/genetics* ; RNA, Ribosomal, 16S/genetics*