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

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

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

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

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*

OBJECTIVETo assess the effect of Spirochetes and Porphyromonus gingivalis (Pg) on the production of volatile sulfur compounds (VSCs) and oral malodor, respectively.

METHODS117 systemically healthy periodontitis patients were divided into two groups according to organoleptic rating (OR) by organoleptic method: 85 subjects with oral malodor (halitosis group, HG) and 32 cases without oral malodor (no-halitosis group, NHG). VSCs measurements were made with halimeter. Subgingival plaques and tongue coating were taken to calculate the proportion of Spirochetes (with 2% Congo Red Smears, S%) and the amounts of Pg (with indirect immunofluorescence method). The examination will be repeated in 46 HG cases after periodontal therapy.

RESULTSS% in PD < 4 mm sites of HG was significantly higher than that in NHG (P < 0.01). S% in PD >or= 4 mm sites and tongue coating, Pg in all three sites were not different between two groups. In HG, OR and VSCs levels were correlated with S% in tongue coating (P < 0.01, P < 0.05) and PD < 4 mm sites (P < 0.05), and not correlated with S% in PD >or= 4 mm sites. OR was related to Pg in PD >or= 4 mm sites (P < 0.05) and there was no relationship between OR and Pg in tongue coating and PD < 4 mm sites. VSCs levels was not correlated with Pg in all three sites. S% in tongue coating and subgingival plaque, Pg in subgingival plaque, OR and VSCs levels were significantly reduced after periodontal therapy (P < 0.01).

CONCLUSIONSThe direct relationship of Spirochetes and Pg respectively to bad breath was not found obviously. But Spirochetes is one of the microorganism on oral malodor. Periodontal therapy can improve oral malodor.

Adolescent ; Adult ; Dental Plaque ; microbiology ; Female ; Halitosis ; microbiology ; Humans ; Male ; Middle Aged ; Periodontitis ; microbiology ; Porphyromonas gingivalis ; metabolism ; Spirochaetales ; metabolism ; Sulfur Compounds ; analysis

China ; Chronic Periodontitis ; microbiology ; Dental Restoration, Permanent ; Genotype ; Humans ; Periodontal Diseases ; surgery ; Periodontics ; trends ; Periodontitis ; genetics ; immunology ; surgery ; Porphyromonas gingivalis ; isolation & purification

OBJECTIVETo compare the endotoxin levels between acute and chronic periapical periodontitis with different clinical symptoms.

METHODS10 cases of acute periapical priodontitis(Group 1), 10 cases of chronic periapical periodontitis (group 2, the diameter of apical radiolucency area was less than 2 mm), 10 cases of chronic periapical periodontitis with sinus(group 3, the diameter of apical radiolucency area was greater than 2 mm), 10 cases of chronic periapical periodontitis without sinus (group 4, the diameter of apical radiolucency area was greater than 2 mm), were included in the study. Chromogenic substrate method of limulus amebocyte lysate(LAL) test was used to measure the endotoxin level.

RESULTSEndotoxin concentrations in group 2 were significantly lower than those in group 1, group 3 and group 4(P < 0.01).

CONCLUSIONEndotoxin plays a very important role in the initiation and development of periapical periodotitis and is closely associated with clinical symptoms and apical radiolucency degree.

Acute Disease ; Bacteria ; Chronic Disease ; Endotoxins ; analysis ; Humans ; Limulus Test ; Periapical Periodontitis ; metabolism ; microbiology ; Root Canal Irrigants