Detection frequency of periodontitis-associated bacteria by polymerase chain reaction in subgingival and supragingival plaque of periodontitis and healthy subjects

Human Herpesviruses, Bacteria, and Fungi in Gingivitis and Periodontitis Pediatric Subjects: A Systematic Review

Objectives: This systematic review assesses and compares the presence and relative abundance of periodontal pathogens, human herpesviruses (HHVs), and fungi in subgingival and/or saliva samples from pediatric subjects (≤18 years of age) with periodontally healthy status and with gingivitis and/or periodontitis. Methods: The study protocol was conducted under the PRISMA statement and registered on PROSPERO (CRD42024593007). Data from seven studies were descriptively analyzed and qualitatively assessed through the ROBINS-1 and JBI tools. Results: Pediatric subjects with clinically healthy periodontium exhibited a balanced microbiome, with early colonizers (Streptococcus species) supporting biofilm development and late colonizers like Fusobacterium nucleatum, Treponema denticola (82.35%), and Porphyromonas gingivalis (29.7%) present at low levels, suggesting subclinical dysbiosis. Viruses such as HSV-I (100%), CMV (17.8%), and EBV-I (22.09%) coexisted in a likely latent state, maintained by effective immune responses. In pediatric periodontitis, biofilms were more diverse and pathogenic, with increased prevalence of A. actinomycetemcomitans (56.09%), P. gingivalis (55.4%), and T. forsythia (35.9%). Generalized periodontitis showed higher CMV (36.36%) and EBV-I (36.24%) prevalence than gingivitis (HSV-I 18.75%). Coinfections were frequent in periodontitis, suggesting bacterial-viral synergy in exacerbating inflammation and tissue destruction. Fungi, although not studied, may also contribute under specific conditions. Conclusions: These findings highlight the role of microbial interactions in periodontal health and disease progression.

Comparative Evaluation of Mogibacterium timidum in the Subgingival Plaque of Periodontally Healthy and Chronic Periodontitis Patients: A Real-Time Polymerase Chain Reaction (PCR) Study

BACKGROUND

Mogibacterium timidum is a new genus of anaerobic bacteria discovered in the year 2000. It is one of the most common bacteria present in the host microbial flora of dental plaque. The levels of M. timidum are supposedly higher in inflammatory conditions.

AIMS AND OBJECTIVES

This study aimed to quantify the levels of M. timidum species in the subgingival plaque samples of healthy patients and patients with chronic periodontitis.

MATERIALS AND METHODS

A total of 24 samples of the subgingival plaque, 12 healthy samples and 12 samples of chronic periodontitis patients, were collected in a buffer solution using a sterile Gracey curette. These samples were then sent to a laboratory for real-time polymerase chain reaction (PCR) testing.

RESULTS

M. timidum was found in higher quantities in plaque samples taken from chronic periodontitis patients when compared to healthy patients.

CONCLUSION

M. timidum can be said to be associated with chronic periodontitis condition. Further studies are required to know the exact nature of the pathogen.

Lactic Acid Bacteria in the Human Oral Cavity: Assessing Metabolic Functions Relevant to Oral Health and Disease

Many perceive lactic acid bacteria as beneficial for health. They are recognized for preventing abnormal fermentation and spoilage of ingested foods by producing lactic acid, which aids in gut acidification. Moreover, lactic acid bacteria are extensively employed in food science. In contrast, lactic acid bacteria in the oral cavity are often perceived as pathogenic factors contributing to the development of dental caries. As a consequence, substantial research has been conducted in oral and dental sciences to explore lactic acid bacteria and the oral microbiome. This research primarily involves analyzing bacterial flora, investigating metabolic activities such as acid production, and investigating metabolic regulation within the oral environment. The oral cavity serves as the gateway to the digestive tract and respiratory system, characterized by a constantly fluctuating environment that significantly impacts the metabolic activity of lactic acid bacteria. Hence, when investigating oral lactic acid bacteria, it is crucial to adopt research plans and methodologies that account for these metabolic environment changes. In this section, we present some of the methods employed in our study.

Factors Associated with the Extent of Clinical Attachment Loss in Periodontitis: A Multicenter Cross-Sectional Study

Periodontitis has significant public health implications, affecting individuals' overall health, well-being, and quality of life. This study aimed to assess the risk factors associated with the extent of clinical attachment loss (CAL) in a population diagnosed with periodontitis. Six hundred and sixty-seven patients with different degrees of CAL (mild, n = 223; moderate, n = 256; and advanced, n = 188) were enrolled. Socio-demographics, lifestyle, microbiological profiles, specific immune response, obesity, and single-nucleotide polymorphism of the IL1 gene were determined. Unconditional logistic regression models were conducted to determine the factors associated with the extent of CAL. Aging, smoking, microbial factors, plaque index, and IgG2 antibodies against Aggregatibacter actinomycetemcomitans were associated with advanced CAL. IgG2 antibodies against A. actinomycetemcomitans (OR 1.50; CI 95% 1.23-1.81), plaque accumulation (OR 2.69; CI 95% 2.20-3.29), Porphyromonas gingivalis (OR 1.93; CI 95% 1.35-2.76), Tanerella forsythia (OR 1.88; CI 95%1.30-2.70), and current smoking (OR 1.94; CI 95% 1.31-2.87) were associated with advanced CAL. Gene IL polymorphisms, obesity, and stress were not associated with the extent of CAL. Aging, plaque accumulation, smoking, and having antibodies against A. actinomycetemcomitans were the most critical factors associated with advanced CAL. In contrast, obesity, stress, and gene polymorphisms were not associated with the extent of CAL.

New putative periodontopathogens and periodontal health-associated species: A systematic review and meta-analysis

To investigate the existence of any association between new putative periodontal pathogens and periodontitis. Two independent reviewers conducted electronic literature searches in the MEDLINE (PubMed), EMBASE, DOSS and Google Scholar databases as well as a manual search to identify eligible clinical studies prior to November 2022. Studies comparing the prevalence of microorganisms other than the already-known periodontal pathogens in subgingival plaque and/or saliva samples between subjects with periodontitis and subject with periodontal health were included. Meta-analyses were performed on data provided by the included studies. Fifty studies including a total of 2739 periodontitis subjects and 1747 subjects with periodontal health were included. The Archaea domain and 25 bacterial species (Anaeroglobus geminatus, Bacteroidales [G-2] bacterium HMT 274, Desulfobulbus sp. HMT 041, Dialister invisus, Dialister pneumosintes, Eubacterium brachy, Enterococcus faecalis, Eubacterium nodatum, Eubacterium saphenum, Filifactor alocis, Fretibacterium sp. HMT 360, Fretibacterium sp. HMT 362, Mogibacterium timidum, Peptoniphilaceae sp. HMT 113, Peptostreptococcus stomatis, Porphyromonas endodontalis, Slackia exigua, Streptococcus gordonii, Selenomonas sputigena, Treponema amylovorum, Treponema lecithinolyticum, Treponema maltophilum, Treponema medium, Treponema parvum and Treponema socranskii) were found to be statistically significantly associated with periodontitis. Network studies should be conducted to investigate the role of these newly identified periodontitis-associated microorganisms through interspecies interaction and host-microbe crosstalk analyses.

Screening of heat-killed lactic acid bacteria based on inhibitory activity against oral bacteria and effects of oral administration of heat-killed Ligilactobacillus salivarius CP3365 on periodontal health in healthy participants: a double-blinded, randomized, placebo-controlled trial

Objectives

The aims of this study were to select heat-killed lactic acid bacteria (HKL) with antibiotic activity and investigate the efficacy of this bacteria in maintaining periodontal parameters in healthy participants.

Materials and methods

An in vitro evaluation was conducted to assess the inhibitory efficacy of lactic acid bacteria against Porphyromonas gingivalis and Fusobacterium nucleatum subsp. nucleatum. The effects of HKL administration on various parameters (plaque control record, bleeding on probing, and probing pocket depth) were assessed in a randomized, placebo-controlled trial. Participants in the test and placebo groups (n = 32) consumed oral tablets containing placebo or HKL daily for 8 weeks. Oral bacteria in supra-plaque and saliva were identified using 16S rRNA gene community profiling analysis.

Results

Heat-killed Ligilactobacillus salivarius CP3365 significantly (p < 0.05) decreased the viability of oral bacteria and was selected for clinical trials. Administration of HKL CP3365 significantly (p < 0.05) inhibited increases in each parameter. No changes in the relative abundance of P. gingivalis or F. nucleatum subsp. nucleatum were detected by HKL CP3365, but the relative abundance of oral bacteria (genera Porphyromonas, Fusobacterium, and Haemophilus) was significantly (p < 0.05) decreased.

Conclusion

HKL CP3365 effectively inhibited oral bacteria growth and was useful for maintaining periodontal health.

Clinical Trial Registration

[https://www.umin.ac.jp/ctr/index.htm], identifier [UMIN000045656].

Newly identified pathogens in periodontitis: evidence from an association and an elimination study

We assessed the level of evidence for the presence of new periodontal pathogens by (i) comparing the occurrence of non-classical periodontal taxa between healthy vs. periodontitis patients (Association study); (ii) assessing the modifications in the prevalence and levels of these species after treatments (Elimination study). In the Association study, we compared the prevalence and levels of 39 novel bacterial species between periodontally healthy and periodontitis patients. In the Elimination study, we analyzed samples from periodontitis patients assigned to receive scaling and root planing alone or with metronidazole+ amoxicillin TID/ 14 days. Levels of 79 bacterial species (39 novel and 40 classic) were assessed at baseline, 3 and 12 months post-therapy. All samples were analyzed using Checkerboard DNA-DNA hybridization. Out of the 39 novel species evaluated, eight were categorized as having strong and four as having moderate association with periodontitis. Our findings suggest strong evidence supporting Lancefieldella rimae, Cronobacter sakazakii, Pluralibacter gergoviae, Enterococcus faecalis, Eubacterium limosum, Filifactor alocis, Haemophilus influenzae, and Staphylococcus warneri, and moderate evidence supporting Escherichia coli, Fusobacterium necrophorum, Spiroplasma ixodetis, and Staphylococcus aureus as periodontal pathogens. These findings contribute to a better understanding of the etiology of periodontitis and may guide future diagnostic and interventional studies.

Selenomonas sputigena Interactions with Gingival Epithelial Cells That Promote Inflammation

Increased prevalence and abundance of Selenomonas sputigena have been associated with periodontitis, a chronic inflammatory disease of tooth-supporting tissues, for more than 50 years. Over the past decade, molecular surveys of periodontal disease using 16S and shotgun metagenomic sequencing approaches have confirmed the disease association of classically recognized periodontal pathogens such as Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia while highlighting previously underappreciated organisms such as Filifactor alocis and S. sputigena. Despite abundant clinical association between S. sputigena and periodontal disease, we have little to no understanding of its pathogenic potential, and virulence mechanisms have not been studied. In this study, we sought to characterize the response of gingival epithelial cells to infection with S. sputigena. Here, we show that S. sputigena attaches to gingival keratinocytes and induces expression and secretion of cytokines and chemokines associated with inflammation and leukocyte recruitment. We demonstrate that S. sputigena induces signaling through Toll-like receptor 2 (TLR2) and TLR4 but evades activation of TLR5. Cytokines released from S. sputigena-infected keratinocytes induced monocyte and neutrophil chemotaxis. These results show that S. sputigena-host interactions have the potential to contribute to bacterially driven inflammation and tissue destruction, the hallmark of periodontitis. Characterization of previously unstudied pathogens may provide novel approaches to develop therapeutics to treat or prevent periodontal disease.

Evaluation and association of periodontal status with levels of Porphyromonas gingivalis in chronic periodontitis with and without Type 2 diabetes mellitus following nonsurgical periodontal therapy using quantitative polymerase chain reaction: An interventional study

Background:

The aim of the present study was to detect and correlate the levels of Porphyromonas gingivalis with clinical parameters after nonsurgical periodontal therapy (NSPT) in chronic periodontitis patients with or without Type 2 diabetes mellitus (T2DM), using quantitative polymerase chain reaction (Q-PCR) method.

Materials and Methods:

Sixty patients equally divided into three groups, i.e., periodontally healthy (Group I), chronic periodontitis (CP) (Group II), and CP with T2DM patients (Group III) were assessed through clinical parameters of probing pocket depth (PPD) and clinical attachment level (CAL) and were correlated for the presence of P. gingivalis in the respective groups. PPD, CAL, and saliva samples for microbiological evaluation were assessed at baseline, 1-, and 3-month post-NSPT.

Results:

Significant reduction of PPD was found 1.26 ± 0.22 versus 0.43 ± 0.33 mm in Group I, 4.62 ± 0.78 versus 2.58 ± 0.60 mm in Group II, and 6.28 ± 1.52 versus 4.01 ± 1.38 mm in Group III post-NSPT at 3 months. Similarly, a notable reduction of CAL was exhibited in both Group II (5.28 ± 0.80 vs. 3.12 ± 0.77 mm) and Group III (7.14 ± 1.59 vs. 4.51 ± 1.38 mm) patients after NSPT at 3 months. A greater reduction of P. gingivalis concentrations was observed in both Group II and Group III at 3-month post-NSPT.

Conclusion:

The substantial improvement of clinical parameters was found to be in correlation with the load of P. gingivalis, which was reduced more in Group II than in Group III, emphasizing the applicability and sensitivity of Q-PCR method for its assessment.

Inquiry-Driven Bioinformatics Laboratory Research Module: Metagenomic Study of Student Oral Microbes

American Society for Microbiology Curriculum Guidelines highlight the importance of enabling students to think critically and learn by doing research. Moreover, information in biology, especially genetics and biotechnology, increases too rapidly for instructors to teach everything. To increase students' interest and comprehension of important core genetic concepts and to encourage students to practice scientific investigation, we designed a research module for upper-level biology/genetics students to examine oral bacteria. Students extracted their own oral microbial DNA and amplified and analyzed with general genus- and species-specific 16S rRNA PCR primers. The microbial DNA samples were also amplified with conserved bacteria 16S rRNA primers and the amplicons TOPO cloned (topoisomerase-based cloning) and Sanger sequenced. Lastly, the metagenomic microbial DNA samples were also sequenced by Illumina next-generation sequencing and analyzed with bioinformatics tools. We have implemented the module in three iterations of an undergraduate class at a small, liberal arts college. The project culminates in a poster presentation that the students on average performed in a high B range. Pre- and postsurvey analysis of student learning gains revealed significant student learning (P < 0.05 one-tailed, paired Wilcoxon signed ranked test, n = 23). Next, we surveyed student perceptions of the activity by a self-assessment. Significantly more than the medians, the students enjoyed the inquiry-driven module and considered it more effective in teaching about PCR and other molecular genetics concepts than the traditional prescribed laboratory exercises. We conclude that this microbe laboratory module induces research interest and is useful in teaching important genetics concepts.

The oralome and its dysbiosis: New insights into oral microbiome-host interactions

The oralome is the summary of the dynamic interactions orchestrated between the ecological community of oral microorganisms (comprised of up to approximately 1000 species of bacteria, fungi, viruses, archaea and protozoa - the oral microbiome) that live in the oral cavity and the host. These microorganisms form a complex ecosystem that thrive in the dynamic oral environment in a symbiotic relationship with the human host. However, the microbial composition is significantly affected by interspecies and host-microbial interactions, which in turn, can impact the health and disease status of the host. In this review, we discuss the composition of the oralome and inter-species and host-microbial interactions that take place in the oral cavity and examine how these interactions change from healthy (eubiotic) to disease (dysbiotic) states. We further discuss the dysbiotic signatures associated with periodontitis and caries and their sequalae, (e.g., tooth/bone loss and pulpitis), and the systemic diseases associated with these oral diseases, such as infective endocarditis, atherosclerosis, diabetes, Alzheimer's disease and head and neck/oral cancer. We then discuss current computational techniques to assess dysbiotic oral microbiome changes. Lastly, we discuss current and novel techniques for modulation of the dysbiotic oral microbiome that may help in disease prevention and treatment, including standard hygiene methods, prebiotics, probiotics, use of nano-sized drug delivery systems (nano-DDS), extracellular polymeric matrix (EPM) disruption, and host response modulators.

Comparison of subgingival and gingival margin plaque microbiota from dogs with healthy gingiva and early periodontal disease

The purpose of the investigation was to determine whether canine gingival margin (GM) plaque is a reliable surrogate for subgingival (SG) plaque from a microbial community (microbiota) perspective. SG and GM plaque samples were collected from 381 dogs visiting pet hospitals in the USA, China and Thailand. Dogs with clinically healthy gingivae through to early periodontitis were included in the study. The samples were subject to next generation Illumina sequence analysis to allow microbiota comparisons to be made between the two plaque sources. Overall, the SG and GM samples indicated commonality via the majority community that were shared between them; health associations led to the identification of some significant taxa-specific differences. GM microbiota exhibited lower variability and diversity and were shown to reflect a sub-population of those associated with SG plaque. Both plaque niches, however, demonstrated similar changes in microbial signatures with health and early periodontal disease and did not indicate divergent trends. The key, most abundant microbiota of GM plaque strongly reflect those observed with SG plaque across health and early periodontitis. Microbiota in plaque from above the gum line may therefore be employed as a biomarker of oral health. This opens up the potential to use plaque, sampled from conscious dogs, to define oral health status and improve the diagnosis, treatments and interventions for periodontal disease.

Effect of feeding a daily oral care chew on the composition of plaque microbiota in dogs

The objective of this study was to investigate the influence of daily feeding of an oral care chew on the composition of canine supragingival plaque microbiota. Twelve beagle dogs were recruited to the randomized cross-over study. The dogs were fed one of two dietary regimes, both consisting of a commercially available wet and dry diet mix, either with or without daily supplementation with an oral care chew. After each 28-day test phase, supragingival plaque samples were collected and processed via Illumina sequencing to determine the microbiota composition. A comparative analysis of bacterial species associated with health and periodontal disease, identified from prior clinical studies, revealed differences between the dietary regimes. Consumption of the daily oral care chew, resulted in a significant increase in proportion of 6 health associated taxa but only 3 disease associated taxa compared to no chew. In contrast, 8 disease and 1 health associated taxa showed increased proportions for no chew versus the oral care chew. Daily feeding of the oral care chew tested in this study has therefore been shown to increase the proportion of health associated bacteria, over bacteria associated with periodontal disease, in supragingival plaque compared to no chew. By influencing plaque microbiota towards a bias for health associated bacteria, feeding of the oral care chew provides a means to reduce the prevalence of bacterial species shown to be associated with periodontal disease in dogs.

Identification of functional domains of the minor fimbrial antigen involved in the interaction of Porphyromonas gingivalis with oral streptococci

Porphyromonas gingivalis is associated with chronic periodontitis and may initially colonize the oral cavity by adhering to streptococci. Adhesion to streptococci is driven by interaction of the minor fimbrial antigen (Mfa1) with streptococcal antigen I/II. We identified the region of antigen I/II required for this interaction and developed small molecule mimetics that inhibited P. gingivalis adherence. However, the functional motifs of Mfa1 involved in the interaction with antigen I/II remain uncharacterized. A series of N- and C-terminal peptide fragments of Mfa1 were expressed and tested for inhibition of P. gingivalis adherence to S. gordonii. This approach identified residues 225-400 of Mfa1 as essential for P. gingivalis adherence. Using the three-dimensional structure of Mfa1, a putative binding cleft was identified using SiteMap and five small molecule mimetics could dock in this site. Site-specific mutation of residues in the predicted cleft, including R240A, W275A, D321A and A357P inhibited the interaction of Mfa1 with streptococci, whereas mutation of residues not in the predicted cleft (V238A, I252F and ΔK253) had no effect. Complementation of an Mfa1-deficient P. gingivalis strain with wild-type mfa1 restored adherence to streptococci, whereas complementation with full-length mfa1 containing the R240A or A357P mutations did not restore adherence. The mutations did not affect polymerization of Mfa1, suggesting that the complemented strains produced intact minor fimbriae. These results identified specific residues and structural motifs required for the Mfa1-antigen I/II interaction and will facilitate the design of small molecule therapeutics to prevent P. gingivalis colonization of the oral cavity.

Correlation of periodontal and microbiological evaluations, with serum levels of estradiol and progesterone, during different trimesters of gestation

Our purpouse was to identify quantitatively and qualitatively the subgingival flora in different gestational trimesters, compared to non-pregnant women; evaluating the correlations between epidemiological characteristics, clinical diagnosis, microbiological findings and levels of estradiol and progesterone. 52 pregnant women divided into 3 groups, according to the gestational trimester and 15 non-pregnant patients, without hormonal contraceptives, were evaluated. Plaque index (PI), gingival index (GI), probing depth (PD) and clinical attachment level (CAL) were evaluated. Subgingival biofilm samples were processed by the qPCR technique and the serum levels of estradiol and progesterone quantified by chemiluminescence. Clinical diagnosis during gestation was correlated with the total bacterial count. A higher prevalence of Tannerella forsythia (Tf) was identified in first trimester of pregnancy and this periodontopathogen was correlated with the diagnosis of gingivitis among pregnant women. Porphyromonas gingivalis (Pg) showed a positive correlation with progesterone levels in the first trimester. High prevalence of periodontopathogens was noticed in this population. Clinical diagnosis in gestation was positively correlated with the total amount of bacteria, without influence of the hormonal levels or the epidemiological factors evaluated. The presence of Tf favored occurrence of gingivitis during pregnancy and the progesterone levels in the first trimester enhanced the growth of Pg.

Subgingival bacterial microbiota associated with ovine periodontitis

ABSTRACT: Periodontitis is an inflammatory response in a susceptible host caused by complex microbiota, predominantly composed of Gram-negative anaerobic bacteria. Aiming to characterize the subgingival bacterial microbiota associated with ovine periodontitis, polymerase chain reaction (PCR) was performed in subgingival periodontal pocket samples of 14 sheep with severe periodontitis and in subgingival sulcus biofilm of 14 periodontally healthy sheep in search mainly of Gram-negative and Gram-positive microorganisms considered important periodontopathogens. The most prevalent bacteria in the sheep with periodontal lesions were Tannerella forsythia (78.6%), Treponema denticola (78.6%), Fusobacterium nucleatum (64.3%), and Porphyromonas gingivalis (50%), whereas in the healthy sheep, F. nucleatum (42.8%) was the most often detected bacterium. Statistically significant differences were observed for Campylobacter rectus, Enterococcus faecium, Prevotella nigrescens, T. forsythia, and T. denticola (p<0.05) in the sheep with periodontitis in the comparison between groups. Aggregatibacter actinomycetemcomitans, Enterococcus faecalis, and Porphyromonas gulae were not detected in any of the samples analyzed. In conclusion, C. rectus, E. faecium, P. nigrescens, T. forsythia, and T. denticola were associated with severe lesions caused by ovine periodontitis, and F. nucleatum was the most prevalent microorganism in the subgengival sulcus biofilm of healthy sheep.

Identification of Salivary Microbiota and Its Association With Host Inflammatory Mediators in Periodontitis

Periodontitis is a microbial-induced chronic inflammatory disease, which may not only result in tooth loss, but can also contribute to the development of various systemic diseases. The transition from healthy to diseased periodontium depends on microbial dysbiosis and impaired host immune response. Although periodontitis is a common disease as well as associated with various systemic inflammatory conditions, the taxonomic profiling of the salivary microbiota in periodontitis and its association with host immune and inflammatory mediators has not been reported. Therefore, the aim of this study was to identify key pathogens and their potential interaction with the host's inflammatory mediators in saliva samples for periodontitis risk assessment. The microbial 16S rRNA gene sequencing and the levels of inflammatory mediators were performed in saliva samples from patients with chronic periodontitis and periodontally healthy control subjects. The salivary microbial community composition differed significantly between patients with chronic periodontitis and healthy controls. Our analyses identified a number of microbes, including bacteria assigned to Eubacterium saphenum, Tannerella forsythia, Filifactor alocis, Streptococcus mitis/parasanguinis, Parvimonas micra, Prevotella sp., Phocaeicola sp., and Fretibacterium sp. as more abundant in periodontitis, compared to healthy controls. In samples from healthy individuals, we identified Campylobacter concisus, and Veillonella sp. as more abundant. Integrative analysis of the microbiota and inflammatory mediators/cytokines revealed associations that included positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rβ. In addition, a negative correlation was identified between IL-10 and Filifactor alocis. Our results reveal distinct and disease-specific patterns of salivary microbial composition between patients with periodontitis and healthy controls, as well as significant correlations between microbiota and host-mediated inflammatory cytokines. The positive correlations between the pathogens Treponema sp. and Selenomas sp. and the cytokines chitinase 3-like 1, sIL-6Rα, sTNF-R1, and gp130/sIL-6Rβ might have the future potential to serve as a combined bacteria-host salivary biomarker panel for diagnosis of the chronic infectious disease periodontitis. However, further studies are required to determine the capacity of these microbes and inflammatory mediators as a salivary biomarker panel for periodontitis.

Subgingival microbiome in Chinese patients with generalized aggressive periodontitis compared to healthy controls

OBJECTIVE

The aim of the study was to profile the subgingival microbiome of Chinese adults with generalized aggressive periodontitis (GAgP) using human oral microbe identification microarray (HOMIM), and to compare the results with matched periodontal healthy controls.

DESIGN

15 subjects with GAgP and 15 age- and gender- matched periodontal healthy controls were included. Subgingival plaque samples were collected from the deepest pockets of patients with GAgP and matched sites in controls and then analyzed by 16S rRNA-based microarrays. Student's paired t-test was used to compare clinical parameters and mean number of bacterial taxa detected between the two groups. Fisher's exact probability test and Wilcoxon Rank Sum were used to compare bacterial species between all samples. A multiple linear regression model was used for correlations among age, gender and bacterial with clinical parameters.

RESULTS

From a total sum of 379 strains tested, 171 bacterial strains were detected from subgingival plaques of the GAgP patients, more than the 157 strains detected in control group. Mean number of subgingival bacterial taxa detected in GAgP group was 68 (SD = 21.06) while in control group was 45 (SD = 21.60). 47 bacterial taxa were detected more frequently in GAgP group while 12 taxa were more prevalent in control group. The significantly more prevalent and abundant taxa of bacteria in GAgP group included Filifactor alocis, Desulfobulbus sp., Fretibacterium sp., Porphyromonas gingivalis, Tannerella forsythia, Porphyromon as endodontalis, Peptostreptococcaceae spp., Parvimonas micra, Eubacterium nodatum and Eubacterium saphenum. Meanwhile the more abundant taxa in control group were Streptococcus spp. and Pseudomonas aeruginosa.

CONCLUSIONS

There are more taxa of bacteria in subgingival plaques of Chinese patients with GAgP than in healthy controls. F. alocis, Desulfobulbus sp., Fretibacterium sp., P. gingivalis and T. forsythia are strongly associated with GAgP. High-throughout microbiological results may help dentists have a better understanding of subgingival microbiome of GAgP.

Efficacy of virginiamycin for the control of periodontal disease in calves

ABSTRACT: Periodontal diseases are multifactorial infectious processes caused by complexes of microorganisms, with damage to health, production, and animal welfare. The aim of the present study was to evaluate the efficacy of virginiamycin in the prevention and control of two early forms of periodontal disease: gingivitis and necrotizing gingivitis. Ten weaned calves, aged four to six months, were permanently kept in a single lot under the same rotational grazing regime in a newly reformed area of Panicum maximum. Five of the calves were orally administered 340mg of virginiamycin (Virginiamycin Group) daily for a period of 18 weeks, while the remaining five calves (Control Group) remained under the same food management but did not receive virginiamycin. During this period, animals underwent 18 weekly evaluations regarding periodontal health, with monitoring and recording of clinical parameters of the eight deciduous incisor teeth on the labial and lingual faces. At approximately two-week intervals, nine collections of subgingival sulcus material from five sites of the four right incisor teeth of each animal were performed and subjected to microbiological evaluation using polymerase chain reaction with primers of 25 microorganisms considered potentially pathogenic. After 1440 periodontal clinical evaluations of incisor teeth of the 10 calves, a total of 395 episodes of gingivitis were recorded, of which 267 occurred in the Control Group and 128 in the Virginiamycin Group. Similarly, 89 episodes of necrotizing gingivitis were recorded; 58 in the Control Group and 31 in the Virginiamycin Group. Comparison of between-group means found significant differences for teeth with gingivitis and necrotizing gingivitis (t test; p<0.05). The total number of teeth with gingivitis (p<0.01) and necrotizing gingivitis (p<0.01) in Control Group was significantly higher than that of gingivitis (p<0.01) and necrotizing gingivitis (p<0.05) in the Virginiamycin Group. There was a positive correlation between total occurrence of gingivitis and necrotizing gingivitis in the Virginiamycin Group by Pearson’s test. Virginiamycin had a protective effect on treated animals compared with the Control Group (OR = 0.36: CI (95%) = 0.27-0.43). In the Control Group, Actinomyces israelli (4.74%), domain Archaea (1.58%), Eikenella corrodens (1.05%), Fusobacterium nucleatum (27.37%), class Mollicutes (5.26%); Porphyromonas endodontalis(5.26%); Porphyromonas gulae(0.53%), Prevotella buccae (6.32%), Prevotella loescheii (3.68%), Prevotella nigrescens (8.42%), Prevotella oralis (1.58%), Tannerella forsythia (0.53%), and Treponema denticola (4.21%) were detected at healthy sites, and gingivitis or necrotizing gingivitis samples. In the Virginiamycin Group, A. israelli (3.41%), domain Archaea (0.98%), F. nucleatum (9.27%), class Mollicutes(4.39%), P. endodontalis (4.39%), P. gulae (0.49%), P. buccae (8.29%), P. loescheii (6.83%), P. nigrescens (15.61%), P. oralis (1.46%), Selenomonas sputigena (0.49%), T. forsythia (0.49%), and T. denticola (2.44%) were detected. In conclusion, virginiamycin administered at a dosage of 340mg/animal/day significantly reduced the occurrence of gingivitis and necrotizing gingivitis in cattle maintained on reformed pastures, and was revealed to have action against periodontal bacterial microbiota considered to be potentially pathogenic.

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.

Root Microbiota in Primary and Secondary Apical Periodontitis

Apical periodontitis is an inflammatory disease of the dental periradicular tissues triggered by bacteria colonizing necrotic root canals. Primary apical periodontitis results from the microbial colonization of necrotic pulp tissues. Secondary apical periodontitis results from a persistent infection of incorrectly treated root canals. The aim of this study was to characterize the microbiota present in primary and secondary intraradicular infections associated with apical periodontitis using 16S rRNA gene amplicon sequencing. Teeth exhibiting apical periodontitis with or without root canal treatment were extracted after informed consent. From each tooth, the intraradicular content as well as a dentin sample (control) were collected and subjected to DNA extraction. PCR amplicons of the V3-V4 region of the bacterial 16S rRNA gene were pooled and sequenced (2 × 300) on an Illumina MiSeq instrument. The bioinformatics analysis pipeline included quality filtering, merging of forward and reverse reads, clustering of reads into operational taxonomic units (OTUs), removal of putative contaminant OTUs and assigning taxonomy. The most prevalent and abundant OTU in both dentin and root canal samples was assigned to anaerobic bacterium Fusobacterium nucleatum. Multivariate analysis showed clustering of microbiota by sample type (dentin vs. intraradicular content) and, in root canals, by pathology (primary vs. secondary infection). The proportions of Enterococcus faecalis and F. nucleatum were, respectively, higher and lower when comparing secondary to primary infected root canals. Co-occurrence network analysis provided evidence of microbial interactions specific to the infection type. The identification of bacterial taxa differentially abundant in primary and secondary intraradicular infections may provide the basis for targeted therapeutic approaches aimed at reducing the incidence of apical periodontitis.

Delayed expansion of atrophic mandible (deam): a case report

Purpose

The present case report presents the clinical results of delayed expansion of mandibles by ultrasonic surgery in case of mono edentulous.

Materials and methods

The patients with a residual alveolar ridge thickness between 2,3 and 4,1 mm in the coronal area of posterior mandible was threated. In the first stage, four linear corticotomies were carried out by ultrasonic surgical device; bone expansion was not performed. After 4 weeks, in the second stage, adequate bone expansion, without compromising cortical vascularisation, by utilising a combination of scalpel, thin chisels and threaded osteotomes was achieved and one implant was placement, after filling the gaps with a cortico bovine biomaterial.

Results

The postoperative course was uneventful and final width ridge was 6,17±0,26mm.

Conclusions

The present case report showed that mandibular ridge expansion using a delayed split-crest technique by means of ultrasonic surgery and association with biomaterial clinically lead to a good horizontal bone gain with no fractures of the buccal plate and high implant success rate.

MMP13, TIMP2 and TGFB3 Gene Polymorphisms in Brazilian Chronic Periodontitis and Periimplantitis Subjects

Subjects susceptible to chronic periodontitis (CP) show a high risk for the development of periimplantitis (PI). Both diseases are multifactorial, presenting similarities in their pathophysiology and polygenic profile. MMP-13 (matrix metalloproteinases 13/ collagenase 3) is a collagenolytic enzyme, which expression is induced by TGF beta 3 (transforming growth factor type 3) in human gingival fibroblasts and inhibited by TIMP-2 (tissue inhibitor of metalloproteinase type 2). The aim of this study was to investigate the occurrence of periimplantitis (PI) in subjects with history of chronic periodontitis (CP) and polymorphisms frequency in MMP13, TIMP2 and TGFB3 genes. One hundred and sixty-three volunteers received dental implant placement were submitted to oral and radiographic examination in order to identify past history of CP or presence of PI. Volunteers were divided into 4 groups: Control (without PI and CP, n=72), CP (with CP and without PI, n=28), PI (with PI and without CP, n=28) and diseased (with CP and PI, n=35). The chi-square test correlated genotypes in specific regions of MMP13 (rs2252070), TIMP2 (rs7501477) and TGFB3 (rs2268626) genes, considering the interaction between CP and PI. The results showed that volunteers with CP had 3.2 times more susceptibility to develop PI (p=0.0004) compared to those without CP. No significant association was observed in MMP13, TIMP2 and TGFB3 genes with CP or PI. CP is a risk factor to develop PI, however, there is no association of both diseases with polymorphisms in the MMP13, TIMP2 and TGFB3 genes.

Effect of cigarette smoking on subgingival bacteria in healthy subjects and patients with chronic periodontitis

Background

Cigarette smoking is known to increase the risk of periodontal destruction and developing chronic periodontitis (CP). It is also reported to affect the subgingival bacterial profile among CP patients. However, studies on the effect of smoking on the bacterial profile among healthy subjects are still limited. Therefore, the aim of this study was to investigate the impact of smoking on the subgingival bacterial profile in both healthy adults and CP patients.

Methods

Subgingival plaque samples were collected from CP patients (30 nonsmokers and 9 smokers) and healthy subjects (37 non-smokers and 18 smokers). Genomic DNA was extracted and 25 bacterial species were detected using PCR of 16S rRNA. Comparing smokers to non-smokers from each group was conducted using chi2 and binary logistic regression analysis.

Results

After correcting for confounding factors, the odds of having Slackia exigua, Selenomonas sputigena and Campylobacter rectus was higher among healthy smokers (ORadj = 10.1, 6.62 and 5.62 respectively). While for CP group, the highest odds were observed for Treponema amylovorum, Treponema medium, Slackia exigua and Treponema vincentii (ORadj = 20.7, 7.97, 6.37 and 5.37 respectively) and the increase in Treponema amylovorum was statistically significant (p = 0.05).

Conclusion

Smoking affects the subgingival bacterial profile in healthy individuals and is responsible for the depletion of beneficial bacteria and the increase in periodontopathogenic bacteria. In the CP patient group, our study suggests that subgingival bacteria (particularly Treponema species) make a more substantial contribution in the etiology of CP among non-smokers. Further studies using a larger sample set and more sensitive and quantitative techniques (such as real -time PCR) are needed to enhance our understanding of the exact effect of smoking on subgingival biofilm.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-017-0359-4) contains supplementary material, which is available to authorized users.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Association of three putative periodontal pathogens with chronic periodontitis in Brazilian subjects

Objective

The aim of this study was to evaluate the association of Porphyromonas endodontalis, Filifactor alocis and Dialister pneumosintes with the occurrence of periodontitis.

Material and Methods

Thirty subjects with chronic periodontitis (ChP) and 10 with periodontal health (PH) were included in the study. Nine subgingival biofilm samples were collected as follows: i) PH group - from the mesial/buccal aspect of each tooth in two randomly chosen contralateral quadrants; ii) ChP group - from three sites in each of the following probing depth (PD) categories: shallow (≤3 mm), moderate (4-6 mm) and deep (≥7 mm). Checkerboard DNA-DNA hybridization was used to analyze the samples.

Results

We found the three species evaluated in a higher percentage of sites and at higher levels in the group with ChP than in the PH group (p<0.05, Mann-Whitney test). We also observed these differences when the samples from sites with PD≤4 mm or ≥5 mm of subjects with ChP were compared with those from subjects with PH (p<0.05, Mann-Whitney test). In addition, the prevalence and levels of D. pneumosintes, and especially of F. alocis were very low in healthy subjects (0.12x10⁵ and 0.01x10⁵, respectively).

Conclusion

F. alocis and D. pneumosintes might be associated with the etiology of ChP, and their role in the onset and progression of this infection should be further investigated. The role of P. endodontalis was less evident, since this species was found in relatively high levels and prevalence in the PH group.

Effect of smokeless tobacco products on human oral bacteria growth and viability

To evaluate the toxicity of smokeless tobacco products (STPs) on oral bacteria, seven smokeless tobacco aqueous extracts (STAEs) from major brands of STPs and three tobacco-specific N-nitrosamines (TSNAs) were used in a growth and viability test against 38 oral bacterial species or subspecies. All seven STAEs showed concentration-dependent effects on the growth and viability of tested oral bacteria under anaerobic culture conditions, although there were strain-to-strain variations. In the presence of 1 mg/ml STAEs, the growth of 4 strains decreased over 0.32-2.14 log₁₀ fold, while 14 strains demonstrated enhanced growth of 0.3-1.76 log₁₀ fold, and the growth of 21 strains was not significantly affected. In the presence of 10 mg/ml STAEs, the growth of 17 strains was inhibited 0.3-2.11 log₁₀ fold, 18 strains showed enhanced growth of 0.3-0.97 log₁₀ fold, and 4 strains were not significantly affected. In the presence of 50 mg/ml STAEs, the growth of 32 strains was inhibited 0.3-2.96 log₁₀ fold, 8 strains showed enhanced growth of 0.3-1.0 log₁₀ fold, and 2 strains were not significantly affected. All seven STAEs could promote the growth of 4 bacterial strains, including Eubacterium nodatum, Peptostreptococcus micros, Streptococcus anginosus, and Streptococcus constellatus. Exposure to STAEs modulated the viability of some bacterial strains, with 21.1-66.5% decrease for 4 strains at 1 mg/ml, 20.3-85.7% decrease for 10 strains at 10 mg/ml, 20.0-93.3% decrease for 27 strains at 50 mg/ml, and no significant effect for 11 strains at up to 50 mg/ml. STAEs from snuffs inhibited more tested bacterial strains than those from snus indicating that the snuffs may be more toxic to the oral bacteria than snus. For TSNAs, cell growth and viability of 34 tested strains were not significantly affected at up to 100 μg/ml; while the growth of P. micros was enhanced 0.31-0.54 log₁₀ fold; the growth of Veillonella parvula was repressed 0.33-0.36 log₁₀ fold; and the cell viabilities of 2 strains decreased 56.6-69.9%. The results demonstrate that STAEs affected the growth of some types of oral bacteria, which may affect the healthy ecological balance of oral bacteria in humans. On the other hand, TSNAs did not significantly affect the growth of the oral bacteria.

Detection of Porphyromonas gingivalis and Treponema denticola in chronic and aggressive periodontitis patients: A comparative polymerase chain reaction study

BACKGROUND

The detection frequency of Porphyromonas gingivalis and Treponema denticola in chronic periodontitis (CP) and aggressive periodontitis (AgP) is not explored well in Indian population.

AIM

The study was undertaken to detect P. gingivalis and T. denticola in CP as well as in AgP patients using polymerase chain reaction (PCR), and to determine the relationship between the frequency of these two microorganisms and the severity of clinical periodontal parameters.

MATERIALS AND METHODS

Subgingival plaque samples were collected from ninety participants (thirty CP patients, thirty AgP patients, and thirty healthy participants) and the aforementioned two microorganisms were detected using PCR.

RESULTS

However, when CP and AgP were compared for the detection frequency of two microorganisms, no statistically significant difference was noted. A statistically significant increase in the number of bacteria-positive sites increased as the score of plaque index (PI), gingival index (GI), and clinical attachment level of CP and AgP patients increased. Coexistence of P. gingivalis and T. denticola was frequently observed in deep periodontal pockets.

CONCLUSIONS

Study findings suggest that P. gingivalis and T. denticola are significantly associated with the severity of periodontal tissue destruction. Statistically significant association exists between clinical periodontal parameters such as PI, GI, periodontal pocket depth (PPD), and clinical attachment loss and presence of both the microorganisms.

Presence of Porphyromonas and Prevotella species in the oral microflora of cattle with periodontitis

Abstratc: Bovine periodontitis is a progressive purulent infectious process associated with the presence of strictly and facultative anaerobic subgingival biofilm and epidemiologically related to soil management in large geographic areas of Brazil. This study aimed to detect species of the genera Porphyromonas and Prevotella, which occurr in periodontal pockets of cattle with lesions deeper than 5mm (n=26) and in gingival sulcus of animals considered periodontally healthy (n=25). Presence of the microorganisms was evaluated by independent-culture medium diagnostic method, using polymerase chain reaction (PCR) with specific primers of Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melaninogenica, P. nigrescens, P. oralis and P. tannerae. The species P. endodontalis (80.7%), P. melaninogenica (73.1%) and P. intermedia (61.5%) were the most predominant in samples of cattle with periodontitis. Regarding non-injured gingival sulcus of cattle, P. endodontalis (40%) and P. loeschei (40%) prevailed. Porphyromonas gingivalis, P. gulae and Prevotella tannerae were not detected in the 51 samples studied. Data evaluation by T test, enabled to verify that ocorrence of Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melaninogenica (p=0.00006) and P. oralis (p=0.0028) is correlated with bovine periodontitis.

Effect of Camphylobacter rectus on Serum Iron and Transferrin- In-Vivo Findings

BACKGROUND AND AIM

Periodontopathogens require iron constituents for their growth and metabolism in subgingival crevice. In this study, C.rectus was detected and quantified by using 16s rDNA based PCR in chronic periodontitis and compared with the levels of serum iron, total iron binding capacity and transferrin in chronic periodontitis and healthy sites.

MATERIALS AND METHODS

One hundred twenty subjects divided into chronic periodontitis and healthy controls. Deep subgingival plaque was collected and genomic DNA was extracted from each sample analysed for C.rectus using 16s rRNA based PCR analysis. Blood samples were collected from both groups for estimation of serum iron, serum total iron binding capacity and serum transferrin levels. The quantified bacterial count was compared with blood samples. C. rectus was detected in both groups.

RESULTS

There was significant increase in bacterial count in chronic periodontitis (p<0.05). Serum iron level was significantly raised in healthy group. TIBC and transferrin levels were elevated in periodontitis. Although these differences were non-significant. Regression analysis showed significant linear relationship between C.rectus counts and decreasing iron levels and consequently increasing serum transferrin and TIBC (p<0.05).

CONCLUSION

The preliminary in vivo findings suggests C.rectus requires iron as a significant source of nutrition for its survival and growth form its hosts in deeper subgingival sites.

Genomic identification and quantification of microbial species adhering to toothbrush bristles after disinfection: A cross-over study

PURPOSE

The aim of this clinical investigation was to identify and quantify the microbial species adhering to toothbrush bristles after controlled brushing and storage in different antimicrobial agents.

METHODS

Sixteen healthy participants were enrolled in this study and randomly submitted to 4 interventions in a cross-over design: brushing and toothbrush storage in (I) Periogard/(II) Periobio (Chlorhexidine gluconate 0.12%), (III) Cepacol (cetylpyridinium chloride 0.05%) and (IV) distilled water (positive control). Thirty-eight bacterial species including putative pathogens and 5 Candida spp. were assessed by Checkerboard DNA-DNA hybridization.

RESULTS

The results of the study have shown a striking reduction of the total microbial counts, including bacteria and Candida spp., on the toothbrush bristles after storage in cetylpyridinium chloride 0.05% (p < 0.0001). Chlorhexidine gluconate 0.12% showed no differences on the total bacterial count when compared to distilled water (p > 0.05). Cetylpyridinium chloride solution also presented the lowest genome counts and frequency of detection for individual target species; distilled water showed the highest individual genome counts (p < 0.05). Potential pathogenic species were recorded in moderate to high levels for chlorhexidine gluconate and distilled water.

CONCLUSION

Cetylpyridinium chloride 0.05% was the most effective storage solution in the reduction of total and individual microbial counts, including pathogenic species.

Quantification of Selenomonas sputigena in Chronic Periodontitis in Smokers Using 16S rDNA Based PCR Analysis

BACKGROUND AND AIM

Selenomonas species have been associated with chronic periodontitis and have been implicated in converting periodontal health to disease. Scanty literature is available in Indian population. Hence, the objective of the study was to detect the prevalence of Selenomonas sputigena in healthy and chronic periodontitis by polymerase chain reaction (PCR) in Indian population and to check whether smoking affects the subgingival microflora of this organism in chronic periodontitis.

MATERIALS AND METHODS

A total of 60 subjects with severe chronic periodontitis with or without smoking and periodontal healthy subjects underwent clinical and microbiological assessment. A deep subgingival plaque sample was collected and genomic DNA was extracted from each sample and analysed for detection of Selnomonas sputigena using PCR. The frequency and quantification of bacteria were also estimated.

RESULTS

All groups differed statistically significant in the frequency of detection of Selenomonas sputigena. On comparison of patients with chronic periodontitis in smokers and non-smokers, there was no statistically significant difference. When the results were quantified, statistically non-significant results were seen among all groups. Plaque index, gingival index, probing pocket depth and clinical attachment level were statistically non-significant in chronic periodontitis with smokers and non-smokers.

CONCLUSION

Prevalence of Selenomonas sputigena showed significant differences with respect to the frequency of detection when comparing the disease group to the healthy population. But no significant difference was seen when the results were quantified. Smoking has no influence on number of Selenomonas sputigena. This study highlights presence as well as quantity of the organism is very important in elucidating its role in causation and progression of the disease.

Treponema denticola in microflora of bovine periodontitis

Periodontitis in cattle is an infectious purulent progressive disease associated with strict anaerobic subgingival biofilm and is epidemiologically related to soil management at several locations of Brazil. This study aimed to detect Treponema species in periodontal pockets of cattle with lesions deeper than 5mm in the gingival sulcus of 6 to 24-month-old animals considered periodontally healthy. We used paper cones to collect the materials, after removal of supragingival plaques, and kept frozen (at -80°C) up to DNA extraction and polymerase chain reaction (PCR) using T. amylovorum, T. denticola, T. maltophilum, T. medium and T. vincentii primers. In periodontal pocket, it was possible to identify by PCR directly, the presence of Treponema amylovorum in 73% of animals (19/26), T. denticola in 42.3% (11/26) and T. maltophilum in 54% (14/26). Among the 25 healthy sites, it was possible to identify T. amylovorum in 18 (72%), T. denticola in two (8%) and T. maltophilum in eight (32%). Treponema medium and T. vincentii were not detected over all 51 evaluated samples. The presence of Treponema amylovorum, T. maltophilum and, in particular, the widely recognized T. denticola in subgingival microflora brings an original and potencially important contribution in studies of the bovine periodontitis.

Rapid and sensitive PCR-dipstick DNA chromatography for multiplex analysis of the oral microbiota

A complex of species has been associated with dental caries under the ecological hypothesis. This study aimed to develop a rapid, sensitive PCR-dipstick DNA chromatography assay that could be read by eye for multiplex and semiquantitative analysis of plaque bacteria. Parallel oligonucleotides were immobilized on a dipstick strip for multiplex analysis of target DNA sequences of the caries-associated bacteria, Streptococcus mutans, Streptococcus sobrinus, Scardovia wiggsiae, Actinomyces species, and Veillonella parvula. Streptavidin-coated blue-colored latex microspheres were to generate signal. Target DNA amplicons with an oligonucleotide-tagged terminus and a biotinylated terminus were coupled with latex beads through a streptavidin-biotin interaction and then hybridized with complementary oligonucleotides on the strip. The accumulation of captured latex beads on the test and control lines produced blue bands, enabling visual detection with the naked eye. The PCR-dipstick DNA chromatography detected quantities as low as 100 pg of DNA amplicons and demonstrated 10- to 1000-fold higher sensitivity than PCR-agarose gel electrophoresis, depending on the target bacterial species. Semiquantification of bacteria was performed by obtaining a series of chromatograms using serial 10-fold dilution of PCR-amplified DNA extracted from dental plaque samples. The assay time was less than 3 h. The semiquantification procedure revealed the relative amounts of each test species in dental plaque samples, indicating that this disposable device has great potential in analysis of microbial composition in the oral cavity and intestinal tract, as well as in point-of-care diagnosis of microbiota-associated diseases.

Newly identified pathogens associated with periodontitis: a systematic review

There is substantial evidence supporting the role of certain oral bacteria species in the onset and progression of periodontitis. Nevertheless, results of independent-culture diagnostic methods introduced about a decade ago have pointed to the existence of new periodontal pathogens. However, the data of these studies have not been evaluated together, which may generate some misunderstanding on the actual role of these microorganisms in the etiology of periodontitis. The aim of this systematic review was to determine the current weight of evidence for newly identified periodontal pathogens based on the results of "association" studies. This review was conducted and reported in accordance with the PRISMA statement. The MEDLINE, EMBASE, and Cochrane databases were searched up to September 2013 for studies (1) comparing microbial data of subgingival plaque samples collected from subjects with periodontitis and periodontal health and (2) evaluating at least 1 microorganism other than the already-known periodontal pathogens. From 1,450 papers identified, 41 studies were eligible. The data were extracted and registered in predefined piloted forms. The results suggested that there is moderate evidence in the literature to support the association of 17 species or phylotypes from the phyla Bacteroidetes, Candidatus Saccharibacteria, Firmicutes, Proteobacteria, Spirochaetes, and Synergistetes. The phylum Candidatus Saccharibacteria and the Archaea domain also seem to have an association with disease. These data point out the importance of previously unidentified species in the etiology of periodontitis and might guide future investigations on the actual role of these suspected new pathogens in the onset and progression of this infection.

Centipeda periodontii in human periodontitis

This study assessed the subgingival occurrence of the flagellated, Gram-negative, anaerobic rod Centipeda periodontii in chronic periodontitis and periodontal health/gingivitis with species-specific nucleic acid probes, and evaluated the in vitro resistance of subgingival isolates to therapeutic levels of amoxicillin, metronidazole, and doxycycline. Subgingival plaque biofilm specimens from 307 adults with chronic periodontitis, and 48 adults with periodontal health/localized gingivitis, were evaluated with digoxigenin-labeled, whole-chromosomal, DNA probes to C. periodontii ATCC 35019 possessing a 10(4) cell detection threshold. Fifty-two C. periodontii subgingival culture isolates were assessed on antibiotic-supplemented enriched Brucella blood agar for in vitro resistance to either amoxicillin at 2 µg/ml, metronidazole at 4 µg/ml, or doxycycline at 2 µg/ml. A significantly greater subgingival occurrence of C. periodontii was found in chronic periodontitis subjects as compared to individuals with periodontal health/gingivitis (13.4 vs. 0 %, P < 0.003), although high subgingival counts of the organism (≥ 10(6) cells) were rarely detected (1.3 % of chronic periodontitis subjects). In vitro resistance was not found to amoxicillin or metronidazole, and to doxycycline in only 2 (3.9 %) of the 52 C. periodontii clinical isolates studied. These findings indicate that C. periodontii is not a major constituent of the subgingival microbiome in chronic periodontitis or periodontal health/gingivitis. The potential contribution of C. periodontii to periodontal breakdown in the few chronic periodontitis subjects who yielded high subgingival levels of the organism remains to be delineated. C. periodontii clinical isolates were susceptible in vitro to therapeutic concentrations of three antibiotics frequently used in treatment of human periodontitis.

Comparison of culture and polymerase chain reaction techniques in the identification of Tannerella forsythia in periodontal health and disease, an in vitro study

Background and Objectives:

Various bacterial species from subgingival biofilm have demonstrated aetiological relevance in the initiation and progression of periodontitis. The aim of this study was to detect the presence of Tannerella forsythia (Tf) in subgingival plaque of periodontally healthy subjects and chronic periodontitis patients by using both culture and PCR technique and compare the two techniques.

Materials and Methods:

Pooled subgingival plaque samples were taken using sterile curettes from predetermined sites in 50 periodontally healthy subjects and from 50 periodontitis subjects. Samples were analyzed for the presence of T. forsythia using both techniques. Statistical analysis of the results was done using Chi-square test, sensitivity, and specificity tests.

Results:

Both techniques could detect T. forsythia in subgingival plaque samples from healthy and periodontitis subjects. Periodontally healthy individuals and individuals with chronic periodontitis using the culture technique showed the presence of T. forsythia in 14 and 34%, respectively. PCR technique showed the presence of T. forsythia in 20% healthy and 40% chronic periodontitis patients. T. forsythia detection in the periodontitis group was statistically significantly higher when compared to the healthy group by both culture and PCR technique (P = 0.019 and P = 0.029). PCR demonstrated high sensitivity and low specificity when compared to the culture technique.

Conclusion:

The results indicated that T. forsythia was more prevalent in periodontitis patients when compared with healthy subjects. The PCR was found to be more sensitive than culture technique for detection of T. forsythia from the subgingival plaque samples.

Development and evaluation of new primers for PCR-based identification of Prevotella intermedia

The aim of this study was to develop new Prevotella intermedia-specific PCR primers based on the 16S rRNA. The new primer set, Pi-192 and Pi-468, increased the accuracy of PCR-based P. intermedia identification and could be useful in the detection of P. intermedia as well as epidemiological studies on periodontal disease.

Lessons learned and unlearned in periodontal microbiology

Periodontal diseases are initiated by bacterial species living in polymicrobial biofilms at or below the gingival margin and progress largely as a result of the inflammation elicited by specific subgingival species. In the past few decades, efforts to understand the periodontal microbiota have led to an exponential increase in information about biofilms associated with periodontal health and disease. In fact, the oral microbiota is one of the best-characterized microbiomes that colonize the human body. Despite this increased knowledge, one has to ask if our fundamental concepts of the etiology and pathogenesis of periodontal diseases have really changed. In this article we will review how our comprehension of the structure and function of the subgingival microbiota has evolved over the years in search of lessons learned and unlearned in periodontal microbiology. More specifically, this review focuses on: (i) how the data obtained through molecular techniques have impacted our knowledge of the etiology of periodontal infections; (ii) the potential role of viruses in the etiopathogenesis of periodontal diseases; (iii) how concepts of microbial ecology have expanded our understanding of host-microbe interactions that might lead to periodontal diseases; (iv) the role of inflammation in the pathogenesis of periodontal diseases; and (v) the impact of these evolving concepts on therapeutic and preventive strategies to periodontal infections. We will conclude by reviewing how novel systems-biology approaches promise to unravel new details of the pathogenesis of periodontal diseases and hopefully lead to a better understanding of their mechanisms.

Salivary carriage of periodontal pathogens in generalized aggressive periodontitis families

BACKGROUND

Generalized aggressive periodontitis (GAP) is a multifactorial disease that shows a specific microbial profile and a familial aggregation.

AIM

This study evaluated the salivary microbial profile of families with a history of GAP and compared them with healthy families.

DESIGN

Fifteen families with parents presenting periodontal health and 15 with parents with a history of GAP were selected. Each family had a child aged 6-12 years. Stimulated saliva was collected from all subjects, and Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), and Aggregatibacter actinomycetemcomitans (Aa) amounts were determined.

RESULTS

Children of GAP families showed higher detection of Aa (90%) than children of healthy families (45%) (P < 0.05). Parents with GAP showed a Pg salivary concentration statistically higher than that of healthy parents (P < 0.05).Children of GAP families, however, exhibited similar Pg concentration than healthy children (P > 0.05). Tf amounts did not differ either in parents or in children (P > 0.05) The infection risk calculation indicates that children who have one parent who is positive for Aa have 16.3 times (95% CI 3.1-87.2) more risk of being infected with Aa (P < 0.05) than children from an Aa-negative family.

CONCLUSION

It may be concluded that children of parents with aggressive periodontitis have higher levels and higher risk of Aa infection.

Microbial interactions in building of communities

Establishment of a community is considered to be essential for microbial growth and survival in the human oral cavity. Biofilm communities have increased resilience to physical forces, antimicrobial agents and nutritional variations. Specific cell-to-cell adherence processes, mediated by adhesin-receptor pairings on respective microbial surfaces, are able to direct community development. These interactions co-localize species in mutually beneficial relationships, such as streptococci, veillonellae, Porphyromonas gingivalis and Candida albicans. In transition from the planktonic mode of growth to a biofilm community, microorganisms undergo major transcriptional and proteomic changes. These occur in response to sensing of diffusible signals, such as autoinducer molecules, and to contact with host tissues or other microbial cells. Underpinning many of these processes are intracellular phosphorylation events that regulate a large number of microbial interactions relevant to community formation and development.

Microbial sampling process can change results of microbiological analysis in periodontitis diagnosis. A minireview

This minireview aims to verify the supposition that the microbial sampling process can change results of microbiological analysis in periodontitis diagnosis. The literature search via Pubmed yielded 52 appropriate articles for analysis. Of which 38% (20/52) described that the sampling sites were isolated from saliva, whereas 62% (32/52) did not. Also, 29% (15/52) declared that the microbial sampling was performed before probing pocket depth (PPD), whereas 71% (37/52) did not. Comparison of the results of microbiological analysis in these studies showed that the bacteria most frequently detected in periodontal pockets was variable. Therefore, a sampling process that includes both the microbial sample being taken before PPD and saliva isolation of the sampling sites is needed to ensure the accuracy of microbiological analysis in periodontitis diagnosis.

Beyond the red complex and into more complexity: the polymicrobial synergy and dysbiosis (PSD) model of periodontal disease etiology

Recent advancements in the periodontal research field are consistent with a new model of pathogenesis according to which periodontitis is initiated by a synergistic and dysbiotic microbial community rather than by select 'periopathogens', such as the 'red complex'. In this polymicrobial synergy, different members or specific gene combinations within the community fulfill distinct roles that converge to shape and stabilize a disease-provoking microbiota. One of the core requirements for a potentially pathogenic community to arise involves the capacity of certain species, termed 'keystone pathogens', to modulate the host response in ways that impair immune surveillance and tip the balance from homeostasis to dysbiosis. Keystone pathogens also elevate the virulence of the entire microbial community through interactive communication with accessory pathogens. Other important core functions for pathogenicity require the expression of diverse molecules (e.g. appropriate adhesins, cognate receptors, proteolytic enzymes and proinflammatory surface structures/ligands), which in combination act as community virulence factors to nutritionally sustain a heterotypic, compatible and proinflammatory microbial community that elicits a non-resolving and tissue-destructive host response. On the basis of the fundamental concepts underlying this model of periodontal pathogenesis, that is, polymicrobial synergy and dysbiosis, we term it the PSD model.

Clinical and microbiological parameters in patients with self-ligating and conventional brackets during early phase of orthodontic treatment

OBJECTIVE

To determine the effect of different bracket designs (conventional brackets and self-ligating brackets) on periodontal clinical parameters and periodontal pathogens in subgingival plaque.

MATERIAL AND METHODS

The following inclusion criteria were used: requirement of orthodontic treatment plan starting with alignment and leveling, good general health, healthy periodontium, no antibiotic therapy in the previous 6 months before the beginning of the study, and no smoking. The study sample totaled 38 patients (13 male, 25 female; mean age, 14.6 ± 2.0 years). Patients were divided into two groups with random distribution of brackets. Recording of clinical parameters was done before the placement of the orthodontic appliance (T0) and at 6 weeks (T1), 12 weeks (T2), and 18 weeks (T3) after full bonding of orthodontic appliances. Periodontal pathogens of subgingival microflora were detected at T3 using a commercially available polymerase chain reaction test (micro-Dent test) that contains probes for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia, and Treponema denticola.

RESULTS

There was a statistically significant higher prevalence of A actinomycetemcomitans in patients with conventional brackets than in patients with self-ligating brackets, but there was no statistically significant difference for other putative periodontal pathogens. The two different types of brackets did not show statistically significant differences in periodontal clinical parameters.

CONCLUSION

Bracket design does not seem to have a strong influence on periodontal clinical parameters and periodontal pathogens in subgingival plaque. The correlation between some periodontal pathogens and clinical periodontal parameters was weak.