Differences in subgingival microflora of Korean and German periodontal patients

What Are the Potential Benefits of Using Bacteriophages in Periodontal Therapy?

Periodontitis, which may result in tooth loss, constitutes both a serious medical and social problem. This pathology, if not treated, can contribute to the development of, among others, pancreatic cancer, cardiovascular diseases or Alzheimer’s disease. The available treatment methods are expensive but not always fully effective. For this reason, the search for and isolation of bacteriophages specific to bacterial strains causing periodontitis seems to be a great opportunity to target persistent colonization by bacterial pathogens and lower the use of antibiotics consequently limiting further development of antibiotic resistance. Furthermore, antimicrobial resistance (AMR) constitutes a growing challenge in periodontal therapy as resistant pathogens may be isolated from more than 70% of patients with periodontitis. The aim of this review is to present the perspective of phage application in the prevention and/or treatment of periodontitis alongside its complicated multifactorial aetiology and emphasize the challenges connecting composition and application of effective phage preparation.

Prevalence and abundance of 9 periodontal pathogens in the saliva of periodontally healthy adults and patients undergoing supportive periodontal therapy

PURPOSE

This study aimed to examine the prevalence and abundance of 9 representative periodontal pathogens in the saliva samples of periodontally healthy subjects (PH) and patients with periodontitis who underwent supportive periodontal therapy (SPT). The age-specific distribution of these pathogens in periodontally healthy individuals was also analyzed.

METHODS

One hundred subjects (aged >35 years) were recruited (50 each in the PH and SPT groups) between August 2016 and April 2019. The prevalence and abundance of periodontal pathogens in the PH group were compared with those in periodontally healthy young subjects (94 subjects; aged <35 years), who were included in our previous study. DNA copy numbers of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Campylobacter rectus (Cr), Peptostreptococcus anaerobius (Pa), and Eikenella corrodens (Ec) were analyzed using real-time polymerase chain reaction.

RESULTS

The detection frequencies of all pathogens, except Aa, were high in the PH and SPT groups. The ranking order of pathogen DNA copy numbers was similar in both groups. In both groups, Fn had the highest abundance, Aa had the lowest abundance. Additionally, Td was significantly more abundant in men than in women in both groups (P<0.05). Compared with the PH group, the SPT group exhibited significantly lower total bacteria and Fn abundance and higher Pg abundance (P<0.05). The age-specific pathogen distribution analysis revealed a significantly low Aa abundance and high Tf and Cr abundance in the PH group.

CONCLUSIONS

The clinical parameters and microbial profiles were similar between the SPT and PH groups. However, patients with periodontitis require supportive care to prevent recurrence. As the abundance of some bacteria varied with age, future studies must elucidate the correlation between age-related physiological changes and periodontal bacterial composition.

Comparative analysis of oral microbiome from Zang and Han populations living at different altitudes

OBJECTIVES

The aim of this study was to obtain greater insight into the environmental and genetic factors affecting the oral microbiome.

DESIGN

To this end, we investigated the oral microbiome composition in Han and Zang populations living at different altitudes. The saliva microbiome in 115 individuals from Zang and Han populations living at different altitudes was analyzed using the 16 s rRNA gene sequencing method on the Illumina MiSeq platform. The dominant species in the oral microbiome were verified by quantitative real-time polymerase chain reaction (qPCR) analysis.

RESULTS

The Han population, living at an altitude of 500 m, had higher microbiome diversity than the Zang population living at altitudes of 3000-4000 m. People living at 3000 m had a higher relative abundance of Leptothrix genus, but people living at 500 m had a higher relative abundance of Capnocytophaga genus according to Lefse difference analysis (P < 0.05). Compared to the Zang population, the Han population had higher relative abundances of Porphyromonas and Treponema genus organisms, especially Porphyromonas (P < 0.001). qPCR analysis confirmed that people living at high altitudes had the highest relative abundance of Porphyromonas gingivalis (P < 0.01).

CONCLUSIONS

This study showed that both genetics and the environment had significant influences on the oral microbiome composition. The study proposed a meaningful research direction to explore the relationship between different ethnic and altitude groups and oral diseases, such as periodontal diseases.

Clinical and Microbiological Profiles of Aggressive and Chronic Periodontitis in Congolese Patients: A Cross-sectional Study

Background:

Chronic and aggressive periodontitis were the main forms of periodontitis according to the 1999 classification of periodontal diseases and conditions. Their profile in Congolese patients is still undescribed.

Aim:

The aim of this study was to compare the profile of chronic periodontitis (ChP) with that of aggressive periodontitis (AgP) in Congolese patients.

Materials and Methods:

Thirty-two patients with ChP and 20 with AgP who consulted the dental services at any of the four medical centers in Kinshasa, from April 2017 to April 2018, were enrolled in the cross-sectional study. All patients underwent a full mouth examination, including assessment of the probing pocket depth and clinical attachment level at six sites per tooth. Microbial samples were collected in the deepest pocket in the maxilla and the deepest pocket in the mandible. A deoxyribonucleic acid (DNA) analysis was performed using DNA strip technology. Fisher exact test, the chi-square test, the t test, and the Mann–Whitney test were used for the statistical analysis.

Results:

Patients with AgP were significantly younger than those with ChP (P < 0.001). There was no significant difference in the prevalence of Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, or Prevotella intermedia between the AgP and ChP groups (P > 0.05). Aggregatibacter actinomycetemcomitans was detected in 10% of cases in the AgP group and in none of those in the ChP group (P = 0.143).

Conclusion:

This study shows that the clinical profiles of ChP and AgP are similar in Congolese patients. There were no microbiological differences between these two forms of periodontitis.

A Literature Review of Metagenomics and Culturomics of the Peri-implant Microbiome: Current Evidence and Future Perspectives

Background and objectives: In recent years, many different culture-independent molecular techniques have been developed with the aim of investigating the not yet cultivated part of the resident flora of the oral cavity and of analyzing the peri-implant and periodontal flora both in healthy and diseased sites. The most used technologies are Roche 454 pyrosequencing, Illumina HiSeq/MiSeq, ABI SOLiD and Ion Torrent. Due to these methods, two different approaches are available: Metagenomics and the 16S gene analysis. A complementary strategy was also recently developed: Culturomics. Culturomics consists of different culture conditions that allow a very rapid bacterial identification. The focused question of this review was developed in PICO format in order to investigate the role of metagenomics, 16S gene analysis and culturomics (interventions) in the differential study (comparison) of the peri-implant and periodontal microbiome (outcome) in humans (participants). The secondary aim was the characterization of currents limits and future applications of the three techniques. Methods: The authors performed a literature search on three databases (Web of Science, Scopus and PubMed) from 01/01/2003 to 31/06/2019. Date of last search was: 25/08/19. Any type of article dealing with the analysis of periodontal and peri-implant flora with metagenomic, culturomic or 16S gene analysis was included. No language restrictions were applied. Risk of bias for RCT was assessed using the Cochrane collaboration's tool whereas case-control and cohort studies were evaluated through the Newcastle-Ottawa scale. Results: The initial search resulted in 330 titles in total. After careful evaluation of all results no studies were found to satisfy the primary outcome of the present review. Hence a narrative review dealing with the secondary aim was performed. Conclusions: Metagenomic and 16S gene analysis approaches contributed in clarifying some crucial aspects of the oral microbiome. Based on the reported evidence some bacteria could be found around teeth and implants even in the absence of signs of inflammation and other species are more frequently found in supragingival peri-implant biofilm. Teeth and implants (even if adjacent) seem not to share the same microbiome and healthy teeth have a more diversified one. The same analyses also highlighted that the oral biofilm of smokers is composed by more periodontopathogen bacteria compared to non-smokers and that geographical location and ethnicity seem to play a role in bacterial composition. Culturomics, which has not yet been applied to the study of oral microbiota, consists of the use of different culture conditions and of the identification by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) with the aim of increasing the bacterial repertoire and avoiding the limits of molecular methods. In order to better evaluate perspectives and limits of the all presented approaches further studies comparing the different molecular techniques are encouraged. This review received no funding.

A cross-sectional study on the periodontal status and prevalence of red complex periodontal pathogens in a Japanese population

This large-scale study cross-sectionally examined the periodontal status and prevalence of "red complex" bacteria (Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) in Japanese adults. A total of 977 participants were enrolled in the study. Probing depth (PD), bleeding on probing (BOP), and bone crest level (BCL) were recorded, and the presence of red complex bacteria in the saliva was examined using polymerase chain reaction. The mean BCL value and the percentage of sites with a PD ≥4 mm or the presence of BOP were significantly higher in older participants. The detection rates of P. gingivalis, T. denticola, and T. forsythia were 46.3%, 76.4%, and 61.1%, respectively. The P. gingivalis detection rate significantly increased with age, while those of T. denticola and T. forsythia were comparably high for all age groups. A close correlation between P. gingivalis and the percentage of sites with PD ≥4 mm was indicated by nonlinear canonical correlation analysis. Current smokers exhibited a more advanced disease condition and a significantly higher P. gingivalis detection rate than non-smokers. In conclusion, periodontal condition worsens with age, and P. gingivalis appears to be the red complex bacterium most closely associated with periodontitis.

Differences in the subgingival microbial population of chronic periodontitis in subjects with and without type 2 diabetes mellitus-a systematic review

OBJECTIVES

The purpose of this systematic review was to evaluate the available evidence in the literature in regard to the subgingival microbial population of chronic periodontitis in subjects with type 2 diabetes mellitus (T2DM+PD) compared to non-diabetic subjects (NDM+PD).

MATERIALS AND METHODS

A literature search was conducted at Ovid MEDLINE and EMBASE database from 1980 to 2016, supplemented by hand searching as needed. Studies presenting with at least one of the primary outcomes (presence of any subgingival microorganisms, proportion and/or the amount of any subgingival plaque bacteria in T2DM+PD versus NDM+PD) were included. Screening, data extraction and quality assessment were conducted independently and in duplicate.

RESULTS

From 611 citations, 19 full-text papers were screened and 11 articles were included for critical appraisal by both reviewers. Some evidence of a difference in the microbial profile between chronic PD subjects with and without T2DM was identified. The strength of evidence is strongest in Tannerella forthysia (T .forsythia) which was reported to be less frequent in the diabetic (T2DM+PD) group in five of the studies, followed by a weaker strength of evidence for other periodontal pathogens such as Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), which were also found less frequent in the diabetic (T2DM+PD) group .

CONCLUSION

Only few studies have compared T2DM+PD with NDM+PD. It is therefore strongly recommended that further studies which include four distinct groups of participants (NDM+PD, T2DM+PD, NDM+NPD, T2DM+NPD) instead of using intra-subject comparisons between healthy and diseased sites of the same subjects.

CLINICAL RELEVANCE

Differences in bacterial populations of T2DM+PD in comparison to NDM+PD subjects may indicate the need of different protocols for the treatment of the diabetic patients with periodontal disease.

Periopathogenic bacteria in dental plaque of Congolese patients with periodontitis: A pilot study

Background

Periopathogenic bacteria play an important role in the etiology of periodontal disease. At present, no study screening for periopathogens in the DR Congo was carried out. The aim of this pilot study was to investigate the prevalence of five periopathogens in Congolese patients with periodontitis and to determine the association between these bacteria.

Material and Methods

Twelve patients (eight women and four men) with a mean age of 45 ± 19 years from those consulted in dental services of two medical centers of Kinshasa from April 2017 to October 2017 were included. Full mouth examination was registered, the probing pocket depth and clinical attachment level were assessed at six sites per tooth. Dental subgingival plaque samples were taken in the deepest pocket per arch in the maxilla and mandible. DNA analysis was performed using DNA-strip technology. The Fisher Exact test and Pearson correlation were used for statistical analysis.

Results

Porphyromonas gingivalis and Tannerella forsythia were detected at high level of 92%, Prevotella intermedia at a rate of 75% whereas Treponema denticola was detected in all patients. Aggregatibacter actinomycetemcomitans was not detected. Strong associations were found between three bacteria of the red complex and between T. denticola and P. intermedia (r=1).

Conclusions

This first study investigating periopathogens in subgingival plaque of Congolese with periodontitis demonstrated a high prevalence of the red complex (P. gingivalis, T. forsythia and T. denticola). Associations between different bacteria of this complex were strong.

Key words:Association, bacteria, periopathogen, periodontitis, prevalence.

Probing the diversity of healthy oral microbiome with bioinformatics approaches

The human oral cavity contains a highly personalized microbiome essential to maintaining health, but capable of causing oral and systemic diseases. Thus, an in-depth definition of “healthy oral microbiome” is critical to understanding variations in disease states from preclinical conditions, and disease onset through progressive states of disease. With rapid advances in DNA sequencing and analytical technologies, population-based studies have documented the range and diversity of both taxonomic compositions and functional potentials observed in the oral microbiome in healthy individuals. Besides factors specific to the host, such as age and race/ethnicity, environmental factors also appear to contribute to the variability of the healthy oral microbiome. Here, we review bioinformatic techniques for metagenomic datasets, including their strengths and limitations. In addition, we summarize the interpersonal and intrapersonal diversity of the oral microbiome, taking into consideration the recent large-scale and longitudinal studies, including the Human Microbiome Project.

Clinical, microbiological, and immunological aspects of healthy versus peri-implantitis tissue in full arch reconstruction patients: a prospective cross-sectional study

Background

Due to the world-wide increase in treatments involving implant placement, the incidence of peri-implant disease is increasing. Late implant failure is the result of the inability to maintain osseointegration, whose most important cause is peri-implantitis. The aim of this study was to analyze the clinical, microbiological, and immunological aspects in the peri-implant sulcus fluid (PISF) of patients with healthy dental implants and patients with peri-implantitis.

Methods

PISF samples were obtained from 24 peri-implantitis sites and 54 healthy peri-implant sites in this prospective cross-sectional study. The clinical parameters recorded were: modified gingival index (mGI), modified plaque index (mPI) and probing pocket depth (PPD). The periodontopathogenic bacteria Tannerella forsythia, Treponema denticola and Porphyromonas gingivalis were evaluated, together with the total bacterial load (TBL). PISF samples were analyzed for the quantification of Interleukin (IL)-8, IL-1β, IL-6, IL-10 and Tumor Necrosis Factor (TNF)-α using flow cytometry (FACS).

Results

The mGI and PPD scores in the peri-implantitis group were significantly higher than the healthy group (p < 0.001). A total of 61.5% of the patients with peri-implantitis had both arches rehabilitated, compared with 22.7% of patients with healthy peri-implant tissues; there was no implant with peri-implantitis in cases that received mandibular treatment exclusively (p < 0.05). Concentrations of Porphyromonas gingivalis (p < 0.01), association with bacteria Porphyromonas gingivalis and Treponema denticola (p < 0.05), as well as the TBL (p < 0.05) are significantly higher in the peri-implantitis group. IL-1β (p < 0.01), IL-6 (p < 0.01), IL-10 (p < 0.05) and TNF-α (p < 0.01) are significantly higher at the sites with peri-implantitis compared to healthy peri-implant tissue, while IL-8 did not increase significantly.

Conclusion

The results of the present study involving a limited patient sample suggest that the peri-implant microbiota and which dental arch was rehabilitated involved could contribute to bone loss in peri-implantitis. A significant relationship is observed between the concentration of cytokines (interleukins 1β, 6 and 10 and TNF-α) and the inflammatory response in peri-implantitis tissue.

Subgingival microbiome in smokers and non-smokers in Korean chronic periodontitis patients

Smoking is a major environmental factor associated with periodontal diseases. However, we still have a very limited understanding of the relationship between smoking and subgingival microflora in the global population. Here, we investigated the composition of subgingival bacterial communities from the pooled plaque samples of smokers and non-smokers, 134 samples in each group, in Korean patients with moderate chronic periodontitis using 16S rRNA gene-based pyrosequencing. A total of 17,927 reads were analyzed and classified into 12 phyla, 126 genera, and 394 species. Differences in bacterial communities between smokers and non-smokers were examined at all phylogenetic levels. The genera Fusobacterium, Fretibacterium, Streptococcus, Veillonella, Corynebacterium, TM7, and Filifactor were abundant in smokers. On the other hand, Prevotella, Campylobacter, Aggregatibacter, Veillonellaceae GQ422718, Haemophilus, and Prevotellaceae were less abundant in smokers. Among species-level taxa occupying > 1% of whole subgingival microbiome of smokers, higher abundance (≥ 2.0-fold compared to non-smokers) of seven species or operational taxonomic units (OTUs) was found: Fusobacterium nucleatum, Neisseria sicca, Neisseria oralis, Corynebacterium matruchotii, Veillonella dispar, Filifactor alocis, and Fretibacterium AY349371. On the other hand, lower abundance of 11 species or OTUs was found in smokers: Neisseria elongata, six Prevotella species or OTUs, Fusobacterium canifelinum, Aggregatibacter AM420165, Selenomonas OTU, and Veillonellaceae GU470897. Species richness and evenness were similar between the groups whereas diversity was greater in smokers than non-smokers. Collectively, the results of the present study indicate that differences exist in the subgingival bacterial community between smoker and non-smoker patients with chronic moderate periodontitis in Korea, suggesting that cigarette smoking considerably affects subgingival bacterial ecology.

Characterization and serotype distribution of Aggregatibacter actinomycetemcomitans isolated from a population of periodontitis patients in Spain

OBJECTIVE

There is no study characterizing the variability of Aggregatibacter actinomycetemcomitans isolates in periodontitis patients in Spain. It is therefore the aim of this investigation to study the serotype distribution of A. actinomycetemcomitans strains isolated from periodontitis patients in Spain. The polymorphism of the genes that codifies the leukotoxin and the operon of the cytolethal-distending toxin (cdt) will also be investigated.

DESIGN

From a total of 701 patients samples, 40 A. actinomycetemcomitans-positive periodontitis patients were included in the study (mean age 45.3, 62.5% females) and their clinical periodontal status was assessed. On average, 1-3 isolates from each patient were sub-cultured and characterized by PCR.

RESULTS

Using culture the prevalence of A. actinomycetemcomitans was 5.7%. The most frequent serotype was "b", being 30 patients infected by a unique serotype, while 7 patients showed co-colonization, mostly with serotypes "a" and "b". From the 79 pure isolates obtained, 24 were from serotype "a", 30 from serotype "b", 12 from serotype "c" and 4 from serotype "d". Further characterization of these samples showed that none of these 79 isolates demonstrated the 530-bp deletion in the leukotoxin's promoter region that characterizes the JP2 strain. Conversely 65.8% of the isolates were cdt+.

CONCLUSIONS

The most common serotypes were "a" and "b", being serotype "b" the most prevalent in mono-colonization, while serotypes "e" and "f" were not detected. In the majority of samples, operon that codifies the cdt (65.8%) and the genes responsible for the codification of leukotoxin (100%) were found. None of the isolates were JP2 strains.

Quantification of key periodontal pathogens in insulin-dependent type 2 diabetic and non-diabetic patients with generalized chronic periodontitis

Periodontitis is a common problem in patients with diabetes mellitus (DM), however, differences in the putative periodontal pathogens in subjects with DM compared to non-DM subjects are still inconclusive. The red complex, which includes Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, encompasses the most important pathogens in adult periodontal disease. The aim of the present study was to compare cell numbers of P. gingivalis, T. denticola, T. forsythia and Aggregatibacter actinomycetemcomitans in gingival sulcus of healthy, gingivitis and periodontitis sites of non-diabetes mellitus (NDM), controlled and poorly controlled insulin-dependent DM (CDM and PDM) patients with generalized chronic periodontitis. Subgingival plaque samples were collected from 19 CDM, 19 PDM and 19 NDM patients. Taqman real time-PCR was used to determine bacterial cell number. At subject level, the quantity of red complex bacteria was significantly higher in PDM than those of NDM and positively correlated with HbA1c. At site level (total 342 sites), cell numbers of T. denticola and T. forsythia in healthy sites of CDM and PDM were significantly higher than those of NDM. In gingivitis sites, the numbers of P. gingivalis in CDM and PDM and T. forsythia in PDM were significantly higher than those of NDM while in periodontitis sites, higher quantity of P. gingivalis in PDM was observed. Our study indicated that poor glycemic control is associated with increasing cell numbers of red complex bacteria in subgingival biofilm.

Investigation of the effect of type 2 diabetes mellitus on subgingival plaque microbiota by high-throughput 16S rDNA pyrosequencing

Diabetes mellitus is a major risk factor for chronic periodontitis. We investigated the effects of type 2 diabetes on the subgingival plaque bacterial composition by applying culture-independent 16S rDNA sequencing to periodontal bacteria isolated from four groups of volunteers: non-diabetic subjects without periodontitis, non-diabetic subjects with periodontitis, type 2 diabetic patients without periodontitis, and type 2 diabetic patients with periodontitis. A total of 71,373 high-quality sequences were produced from the V1-V3 region of 16S rDNA genes by 454 pyrosequencing. Those 16S rDNA sequences were classified into 16 phyla, 27 classes, 48 orders, 85 families, 126 genera, and 1141 species-level OTUs. Comparing periodontally healthy samples with periodontitis samples identified 20 health-associated and 15 periodontitis-associated OTUs. In the subjects with healthy periodontium, the abundances of three genera (Prevotella, Pseudomonas, and Tannerella) and nine OTUs were significantly different between diabetic patients and their non-diabetic counterparts. In the subjects carrying periodontitis, the abundances of three phyla (Actinobacteria, Proteobacteria, and Bacteriodetes), two genera (Actinomyces and Aggregatibacter), and six OTUs were also significantly different between diabetics and non-diabetics. Our results show that type 2 diabetes mellitus could alter the bacterial composition in the subgingival plaque.

The sociodemographic characteristics, periodontal health status, and subgingival microbiota of patients with chronic periodontitis and type 2 diabetes mellitus: a case-control study in a Chinese population

BACKGROUND

In China, chronic periodontitis (CP) is common in patients with type 2 diabetes mellitus (T2DM). The purpose of this study is to identify the sociodemographic characteristics associated with such patients and to assess the periodontal health status and subgingival microbiota of patients with CP and T2DM (T2DMCP) in the Chinese population.

METHODS

A total of 150 patients with T2DMCP and 306 patients with CP without any systemic disease completed questionnaires, underwent clinical periodontal examinations and participated in diabetes-related parameter examinations. Subgingival plaques were obtained to determine the prevalence and amounts of selected oral bacterial species using polymerase chain reaction (PCR) and real-time PCR, respectively.

RESULTS

The income level and mean body mass index (BMI) of the patients with T2DMCP were significantly higher than those of the patients with CP. Additionally, the patients with T2DMCP were more likely to be urban residents, and they had significantly more severe periodontitis than did the patients with CP. In the patients with T2DMCP, the prevalence and amounts of Treponema denticola and Tannerella forsythia were significantly higher than those in the patients with CP. Finally, compared with the patients with CP, the patients with T2DMCP had a significantly lower prevalence and amount of Prevotella intermedia.

CONCLUSIONS

Compared with the patients with CP, the patients with T2DMCP were more likely to be urban residents and generally had higher incomes, higher mean BMI, and poorer periodontal health status. Higher levels of T. denticola and T. forsythia and lower levels of P. intermedia were identified in the subgingival plaque of the patients with T2DMCP.

Occurrence of periodontal pathogens among patients with chronic periodontitis

The aim of the present study was to evaluate the presence of the periodontal pathogens that form the red complex (Tannerella forsythia, Porphyromonas gingivalis and Treponema denticola) and Aggregatibacter actinomycetemcomitans in patients with chronic periodontitis. The sample consisted of 29 patients with a clinical and radiographic diagnosis of chronic periodontitis based on the criteria of the American Academy of Periodontology (3). Samples for microbiological analysis were collected from the four sites of greatest probing depth in each patient, totaling 116 samples. These samples were processed using conventional polymerase chain reaction, which achieved the following positive results: 46.6% for P. gingivalis, 41.4% for T. forsythia, 33.6% for T. denticola and 27.6% for A. actinomycetemcomitans. P. gingivalis and T. forsythia were more prevalent (p < 0.05) in periodontal pockets ≥ 8 mm. The combinations T. forsythia + P. gingivalis (23.2%) and T. forsythia + P. gingivalis + T. denticola (20.0%) were more frequent in sites with a probing depth ≥ 8 mm. Associations with the simultaneous presence of A. actinomycetemcomitans + P. gingivalis, A. actinomycetemcomitans + T. forsythia, P. gingivalis + T. forsythia and T. forsythia + T. denticola were statistically significant (p < 0.05). It was concluded that the red complex pathogens are related to chronic periodontitis, presenting a higher occurrence in deep periodontal pockets. Moreover, the simultaneous presence of these bacteria in deep sites suggests a symbiotic relationship between these virulent species, favoring, in this way, a further progression of periodontal disease.