Detection and quantification of five major periodontal pathogens by single copy gene-based real-time PCR

Dietary inflammatory index in relation to salivary cytokine concentrations and periodontitis: A cross-sectional analysis

AIM

To examine the associations of dietary inflammatory index (DII) with salivary cytokine concentrations and periodontitis after controlling for body mass index (BMI), socio-demographic factors and lifestyle.

MATERIALS AND METHODS

Subgroups from two Finnish surveys, DILGOM 2007 and Health 2000, were included (total n = 727). The DII scores were calculated based on a food frequency questionnaire. Periodontal status was assessed with a cumulative risk score in DILGOM 2007 and by pocket depth measurement in Health 2000. From saliva, interleukin (IL)-1β, IL-1 receptor antagonist, IL-6, IL-8, IL-10 and tumour necrosis factor (TNF)-α concentrations were measured.

RESULTS

The DII scores did not differ between non-periodontitis and periodontitis participants in pairwise comparison. After adjusting for energy intake, periodontal status, BMI, age, education level, smoking habit and physical activity, DII was not associated with salivary cytokine concentrations. After adjusting for salivary cytokine levels and other confounding factors, DII was associated with periodontitis in the Health 2000 subgroup but not in the DILGOM 2007 subgroup.

CONCLUSIONS

The current data support the evidence that diet is not associated with salivary cytokine levels but may be associated with periodontitis. The association observed between diet and periodontitis is related to factors other than diet-dependent inflammatory tendency in the oral cavity.

Lipoxin A4 levels predict site-specific clinical improvements post scaling and root planing and correlate negatively with periodontal pathogens in severe periodontitis

BACKGROUND

Serving as a stop signal of inflammation, the role of lipoxin A4 (LXA4) in periodontitis remains to be clarified. This study is aimed to examine the changes in LXA4 levels in gingival crevicular fluid (GCF) after scaling and root planing (SRP) and to determine the relationship between LXA4 levels and treatment outcomes and periodontal pathogens in severe periodontitis.

METHODS

A total of 74 GCF samples were collected from 21 severe periodontitis participants at the deepest affected sites. These sites were re-sampled at 1, 3, and 6 months after SRP. Besides, GCF samples were also collected from 25 periodontally healthy participants. Clinical parameters including probing depth (PD) and clinical attachment level (CAL) in periodontitis group were recorded. LXA4 levels and periodontal pathogens in the GCF were analyzed by ELISA and PCR, respectively. Correlations between GCF LXA4 levels and treatment effect and periodontal pathogens were assessed.

RESULTS

LXA4 levels in GCF significantly increased after SRP (p < 0.05), but remained lower than those observed in healthy individuals (p < 0.05). Sites with lower baseline LXA4 concentrations were more likely to experience greater improvements in PD at 6 months post-SRP (area under the curve [AUC] = 0.792), and the improvements were positively correlated with the increase of LXA4 at these sites post-treatment (p < 0.05). Furthermore, more elevated LXA4 levels were observed in sites that became negative for Prevotella intermedia or Tannerella forsythia after SRP.

CONCLUSION

Baseline LXA4 in GCF has the potential to predict the site-specific response of severe periodontal lesions to SRP. The increase of LXA4 levels after treatment was positively correlated with clinical improvements and negatively correlated with the presence of Prevotella intermedia or Tannerella forsythia.

Effects of three orthodontic retainers on periodontal pathogens and periodontal parameters

The objective of this study was to compare and evaluate the changes in periodontal pathogens and periodontal status within 6 months of wearing three orthodontic retainers, namely, vacuum-formed retainer (VFR), Hawley retainer (HR), and lingual fixed retainer (LR). In total, 48 patients who underwent orthodontic treatment with ordinary metal brackets were divided into VFR, HR, and LR groups (n = 16 per group). Saliva samples were collected at the time of debonding (T0) and after 1 month (T1), 3 months (T2), and 6 months (T3). Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were quantitatively analyzed using real-time PCR. Gingival index (GI), plaque index (PLI), and probing depth (PD) were measured at the four time points to evaluate changes in periodontal state. SPSS20.0 software was used to analyze the data, and P < 0.05 was considered statistically significant. The trial was registered at the Chinese Clinical Trial Registry (ChiCTR2300073704), the registration was retrospective. Compared to baseline (T0) values, Pg, Aa, GI, PLI, and PD were significantly decreased in all three groups 1 month after wearing the retainer (p < 0.05). Significant differences were observed in Aa at T3 among the three groups, whereby the HR group exhibited significantly better results compared to the VFR and LR groups (p < 0.05). Differences were found among the three groups' Porphyromonas gingivalis at T3, and the HR group was significantly better than the VFR and LR groups (P < 0.05). From T1 to T2, GI, PLI, and PD of the three groups tended to be stable, however differences were observed at T3, with the PLI and PD of the HR group being the lowest among the three groups (p < 0.05). Regardless of the type of retainer used, the periodontal condition of patients was significantly improved after removal of the metal brackets. After 6 months of retainer use, the Hawley retainer was superior to vacuum-formed retainer and lingual fixed retainer with regard to Pg, Aa, and periodontal clinical parameters.

Localization and expression profiles of gingival monocyte chemoattractant protein-1-induced protein-1 (MCPIP-1) and mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT-1)

OBJECTIVES

The purposes of this study were to localize monocyte chemoattractant protein-1-induced protein-1 (MCPIP-1) and its suppressor mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT-1) in gingival tissues and to profile their protein expression levels in relation to the clinical inflammation, Porphyromonas gingivalis colonization, and interleukin (IL)-8 levels.

MATERIALS AND METHODS

Study samples were collected from two independent study populations: (1) Gingival tissues were collected from eight periodontally healthy individuals and eight periodontitis patients to localize MCPIP-1 and MALT-1 immunohistochemically, and (2) forty-one gingival tissue samples with marginal, mild, or moderate to severe inflammation were collected from 20 periodontitis patients to determine MCPIP-1 and MALT-1 levels using immunoblots, P. gingivalis levels with qPCR, P. gingivalis gingipain activities with fluorogenic substrates, and IL-8 levels with multiplex technique.

RESULTS

MCPIP-1 was detectable in the epithelium and in connective tissue, being especially prominent around the blood vessel walls in healthy periodontal tissues. MALT-1 was observed at all layers of gingival epithelium and especially around the accumulated inflammatory cells in connective tissue. No difference in gingival tissue MCPIP-1 and MALT-1 levels was observed in relation to the severity of gingival inflammation. MALT-1 levels were elevated (p = 0.023) with the increase in tissue P. gingivalis levels, and there was an association between MALT-1 and IL-8 levels (β = 0.054, p = 0.001).

CONCLUSIONS

Interactions of MALT-1 levels with gingival tissue P. gingivalis counts and IL-8 levels suggest that activation of MALT-1 can take part in P. gingivalis-regulated host immune responses.

CLINICAL RELEVANCE

Pharmacological targeting the crosstalk between immune response and MCPIP-1/MALT-1 may have benefits in periodontal treatment.

The Efficiency of Photodynamic Therapy in the Bacterial Decontamination of Periodontal Pockets and Its Impact on the Patient

Research in the field of periodontal disease continues to focus on disease-associated microorganisms, as the microbial plaque and the host immune responses are considered to be important causative factors, that are highly responsible for the progression of this disease. The purpose of this article is to compare the reduction in the number of specific periodontopathogens in two test groups according to different therapeutic approaches in periodontal disease and to show possible differences. This article is based on a prospective clinical study involving eighteen subjects with forty-four average periodontal pockets assigned to study groups treated by two different methods, SRP and SRP followed by a single PDT application. Efficiency in removing specific bacterial species was evaluated by PCR testing, at baseline and immediately after treatment. The hypothesis that using SRP + aPDT results in an increased decontamination potential was confirmed statistically, when all five specific bacterial pathogens were investigated together. When the pathogens were considered separately, two of the five microorganisms tested were significantly lower in the SRP + PDT group (p < 0.00), and important germ counts reductions were also observed for the other three. There is also a statistically significant relation between the pain at 48 h postoperatively and the type of treatment the patients received, as resulted from the Questionnaire Form. Our results demonstrate that aPDT, as an adjunctive treatment to conservative mechanical cleaning of root surfaces at sites affected by periodontitis, represents an effective tool in terms of reducing specific periodontopathogen germs.

Subgingival Periopathogens Assessment and Clinical Periodontal Evaluation of Gastric Cancer Patients—A Cross Sectional Pilot Study

Oral microbiota have shown a higher bacterial diversity in patients with cancers of the digestive tract, with higher levels of periopathogens. Recent studies have shown that Fusobacterium links to gastro-intestinal neoplastic tissue and accelerates its progression, as well as worsening patient outcome. The present pilot study was carried out between February and December 2020 to evaluate the possible association between the abundance of some periopathogens (Fusobacterium nucleatum, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola and Tannerella forsythia) in subgingival plaque and periodontal status with characteristics of gastric cancer. The study was performed on a sample of 24 patients with gastric cancer from the 1st Department of Surgery and Department of Gastroenterology within the Clinical County Hospital of Emergency of Craiova, Romania. The patients’ oral cavity was examined, gingival crevicular samples were collected, and signs of periodontal disease were recorded. On the histopathological exam, the differentiation grade and size of the tumour were registered. Our results showed that, from the periopathogens studied, the most abundant bacteria were F. nucleatum followed by T. forsythia in all groups. In our present study, the strong correlation between tumour dimension and all periodontal parameters but also between tumour dimension and F. nucleatum could suggest a positive association between periodontal disease, tumoral growth and periopathogens implication in this process.

Succession of oral bacterial colonizers on dental implant materials: An in vitro biofilm model

OBJECTIVES

Oral bacterial adhesion on dental implant materials has been extensively studied using in vitro systems but has yielded results restricted to in vitro growth patterns due to limitations in species selection, sustained fastidious anaerobe growth, and mixed culture longevity. The aim of this study was to develop an oral bacterial biofilm model consisting of colonizers representative of the oral microbiome exhibiting temporal shifts characteristic of plaque development and maturation in vivo.

METHODS

Streptococcus oralis, Actinomyces naeslundii, Aggregatibacter actinomycetemcomitans, Veillonella parvula, Fusobacterium nucleatum, and Porphyromonas gingivalis were grown in monoculture prior to combination in mixed culture. Commercially pure titanium (cpTi) and yttria-stabilized zirconia (ZrO₂) disks with polished, acid-etched, or sandblasted surfaces were prepared to evaluate oral bacterial adhesion. After 6 h, 1, 3, 7, 14 and 21 days, genomic DNA from planktonic and adherent bacteria was isolated. Quantitative polymerase chain reaction (qPCR) was used to enumerate the amount and proportion of each species.

RESULTS

Early-colonizing S. oralis and A. actinomycetemcomitans, dominated after 6 h prior to secondary colonization by F. nucleatum and V. parvula in planktonic (1 day) and sessile (3 days) form. A. naeslundii maintained relatively low but stable bacterial counts throughout testing. After 14 days, late-colonizing P. gingivalis became established in mixed culture and persisted, becoming the dominant species after 21 days. The composition of adherent bacteria across all substrates was statistically similar at all timepoints with notable exceptions including lower S. oralis bacterial counts on polished cpTi (3 days).

SIGNIFICANCE

Within the present model's limitations, multispecies oral bacterial attachment is similar on surface-treated cpTi and ZrO₂.

[Assessment of antimicrobial activity of bioflavonoid CITROX and chlorhexidine combination against P. gingivalis (in vitro)]

OBJECTIVE

The aim of the study - evaluation of the antiseptic properties of the combination of chlorhexidine and bioflavonoid CITROX against P. gingivalis.

MATERIAL AND METHODS

Clinical isolates of microbial cultures from the collection of the Department of Microbiology, Immunology, Virology of the Moscow State Medical University named after A.I. Evdokimov: P. gingivalis. Primary seeding of the studied material was carried out on nutrient media produced by Himedia Laboratories Pvt. Limited (India): Colombian agar with the addition of 5% defibrinated blood and a selective additive for the isolation of non-spore anaerobes. To conduct the experiment, a thermostatic rotary system - RTS-1 (Biosan, Latvia) was used, which performs a modern type of mixing due to the formation of a vortex-type diffusing effect. The interpretation of the results was carried out by changing the optical density index (the indicator in McFarland units) at a wavelength of λ = 850 nm.

RESULTS

The combination of CITROX + chlorhexidine 0.05% more effectively suppresses the growth of periodotopathogenic bacteria than chlorhexidine 0.05%, prolonging the adaptive phase (lag phase) of the growth of P.gingivalis bacteria and can be considered as an alternative to chlorhexidine without additives. Prolongation of the lag phase increases the time until the first clinical symptoms appear, as a result, the body has more time to form an immune response.

CONCLUSION

The combination of the complex of bioflavonoids CITROX and chlorhexidine bigluconate in concentrations of 0.05% and 0.2% is active against P. gingivalis and can be considered as an alternative to chlorhexidine without additives. The inclusion of CITROX in the rinse aid reduces the concentration of chlorhexidine in the rinse aid, which can lead to a decrease in the severity of undesirable effects and be considered as an alternative remedy in the treatment of periodontal diseases.

Systemic Antibiotics Influence Periodontal Parameters and Oral Microbiota, But Not Serological Markers

The use of systemic antibiotics may influence the oral microbiota composition. Our aim was to investigate in this retrospective study whether the use of prescribed antibiotics associate with periodontal status, oral microbiota, and antibodies against the periodontal pathogens. The Social Insurance Institution of Finland Data provided the data on the use of systemic antibiotics by record linkage to purchased medications and entitled reimbursements up to 1 year before the oral examination and sampling. Six different classes of antibiotics were considered. The Parogene cohort included 505 subjects undergoing coronary angiography with the mean (SD) age of 63.4 (9.2) years and 65% of males. Subgingival plaque samples were analysed using the checkerboard DNA-DNA hybridisation. Serum and saliva antibody levels to periodontal pathogens were analysed with immunoassays and lipopolysaccharide (LPS) activity with the LAL assay. Systemic antibiotics were prescribed for 261 (51.7%) patients during the preceding year. The mean number of prescriptions among them was 2.13 (range 1-12), and 29.4% of the prescriptions were cephalosporins, 25.7% penicillins, 14.3% quinolones, 12.7% macrolides or lincomycin, 12.0% tetracycline, and 5.8% trimethoprim or sulphonamides. In linear regression models adjusted for age, sex, current smoking, and diabetes, number of antibiotic courses associated significantly with low periodontal inflammation burden index (PIBI, p < 0.001), bleeding on probing (BOP, p = 0.006), and alveolar bone loss (ABL, p = 0.042). Cephalosporins associated with all the parameters. The phyla mainly affected by the antibiotics were Bacteroidetes and Spirochaetes. Their levels were inversely associated with the number of prescriptions (p = 0.010 and p < 0.001) and directly associated with the time since the last prescription (p = 0.019 and p < 0.001). Significant inverse associations were observed between the number of prescriptions and saliva concentrations of Prevotella intermedia, Tannerella forsythia, and Treponema denticola and subgingival bacterial amounts of Porphyromonas gingivalis, P. intermedia, T. forsythia, and T. denticola. Saliva or serum antibody levels did not present an association with the use of antibiotics. Both serum (p = 0.031) and saliva (p = 0.032) LPS activity was lower in patients having any antibiotic course less than 1 month before sampling. Systemic antibiotics have effects on periodontal inflammation and oral microbiota composition, whereas the effects on host immune responses against the periodontal biomarker species seem unchanged.

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.

Clinical evaluation of periodontal pathogen levels by real-time polymerase chain reaction in peri-implantitis patients

OBJECTIVE

The mechanisms underlying the onset and progression of peri-implantitis are similar to those of periodontitis, and the causative bacteria are believed to similar. Previous studies support an association between peri-implantitis and periodontal pathogen. Thus, we investigated the bacterial flora of peri-implantitis patients in comparison to those of healthy implant and periodontitis patients.

MATERIALS AND METHODS

In total, 70 patients visiting Tokyo Dental College Chiba Hospital were divided into four groups: healthy, periodontitis, healthy implant, and peri-implantitis. For each group, the following five periodontal pathogens were detected using real-time polymerase chain reaction: Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia, Treponema denticola, and Prevotella intermedia.

RESULTS

The average copy number of total bacteria was significantly higher in the periodontitis group than in the other groups. P. gingivalis was detected in the periodontitis and peri-implantitis groups at levels as high as 18.92% and 12.29%, respectively, and P. intermedia was found in the peri-implantitis group at a rate of 2.06%. Nevertheless, periodontal pathogens were generally detected at lower levels in the peri-implantitis group than in the periodontitis group.

CONCLUSION

We found lower bacterial counts in the peri-implantitis group relative to the periodontitis group. Our results suggest that the peri-implant tissue is less resistant to bacteria, so even a small number of bacteria can be a risk factor for peri-implantitis and the causative agent of peri-implantitis can be bacteria other than periodontal pathogen.

Salivary IgA antibody to malondialdehyde-acetaldehyde associates with mild periodontal pocket depth

OBJECTIVE

Oxidized epitopes such as malondialdehyde-acetaldehyde (MAA) play a crucial role in the progression of atherosclerosis through activation of the humoral immune response. The exact mechanism of the association between atherosclerosis and periodontal diseases is not fully understood. The aim of the current study is to evaluate the association of oral humoral immune response to oxidized epitopes with parameters of periodontal disease.

MATERIALS AND METHODS

The Parogene cohort consist of patients who have undergone coronary angiography due to cardiac symptoms. In this study, 423 patients were randomly selected for an extensive oral examination. Salivary Immunoglobulin A to oxidized epitopes and bacterial antigens was determined by chemiluminescence immunoassay.

RESULTS

In a binary logistic regression model adjusted with periodontal disease confounders, periodontal pocket depth (PPD) 4-5 mm associated with salivary IgA antibodies to MAA-LDL (p = 0.034), heat shock protein 60 of Aggregatibacter actinomycetemcomitans (p = 0.045), Porphyromonas gingivalis (p = 0.045), A. actinomycetemcomitans (p = 0.005), P. intermedia (p = 0.020), and total IgA (p = 0.003).

CONCLUSIONS

The current study shows the association of salivary IgA to MAA-LDL with PPD 4-5 mm in a cohort of patients with chronic coronary artery disease. Humoral immune cross-reactivation to oxidized epitopes such MAA-LDL could partly explain the link of periodontitis with systemic diseases.

Developing Lactic Acid Bacteria as an Oral Healthy Food

Lactic acid bacteria have functions in immunoregulation, antagonism, and pathogen inhibition. The purpose of this study was to evaluate the effectiveness of lactic acid bacteria (LAB) in countering oral pathogens and develop related products. After a series of assays to 450 LAB strains, 8 heat-inactivated strains showed a strong inhibitory effect on a caries pathogen, Streptococcus mutans, and 308 heat-inactivated LAB strains showed a strong inhibitory effect on a periodontal pathogen, Porphyromonas gingivalis. The key reasons for inhibiting oral pathogens were bacteriocins produced by LAB and the coaggregation effect of the inactivated cells. We selected Lacticaseibacillus (Lb) paracasei 111 and Lb.paracasei 141, which had the strongest inhibitory effects on the above pathogens, was the main oral health food source. The optimal cultural conditions of Lb. paracasei 111 and Lb. paracasei 141 were studied. An oral tablet with a shelf life of 446 days made of the above strains was developed. A 40 volunteers' clinical study (CSMUH IRB number: CS05065) was conducted with this tablet in the Periodontological Department of the Stomatology Research Center, Affiliated Hospital of Chung Shan Medical University (Taiwan). After 8 weeks of testing, 95% and 78.9% of patients showed an effect on reducing periodontal pathogens and improving probing pocket depth, respectively, in the oral tablet group.

The Loop-Mediated Isothermal Amplification Technique in Periodontal Diagnostics: A Systematic Review

The course of periodontal disease is affected by many factors; however, the most significant are the dysbiotic microflora, showing different pathogenicity levels. Rapid colonization in the subgingival environment can radically change the clinical state of the periodontium. This systematic review aims to present an innovative technique of loop-mediated isothermal amplification for rapid panel identification of bacteria in periodontal diseases. The decisive advantage of the loop-mediated isothermal amplification (LAMP) technique in relation to molecular methods based on the identification of nucleic acids (such as polymerase chain reaction (PCR or qPCR) is the ability to determine more pathogens simultaneously, as well as with higher sensitivity. In comparison with classical microbiological seeding techniques, the use of the LAMP method shortens a few days waiting time to a few minutes, reducing the time necessary to identify the species and determine the number of microorganisms. The LAMP technology requires only a small hardware base; hence it is possible to use it in outpatient settings. The developed technique provides the possibility of almost immediate assessment of periodontal status and, above all, risk assessment of complications during the treatment (uncontrolled spread of inflammation), which can certainly be of key importance in clinical work.

Quantification of Bacteria in Mouth-Rinsing Solution for the Diagnosis of Periodontal Disease

This study aimed to evaluate the feasibility of diagnosing periodontitis via the identification of 18 bacterial species in mouth-rinse samples. Patients (n = 110) who underwent dental examinations in the Department of Periodontology at the Veterans Health Service Medical Center between 2018 and 2019 were included. They were divided into healthy and periodontitis groups. The overall number of bacteria, and those of 18 specific bacteria, were determined via real-time polymerase chain reaction in 92 mouth-rinse samples. Differences between groups were evaluated through logistic regression after adjusting for sex, age, and smoking history. There was a significant difference in the prevalence (healthy vs. periodontitis group) of Aggregatibacter actinomycetemcomitans (2.9% vs. 13.5%), Treponema denticola (42.9% vs. 69.2%), and Prevotella nigrescens (80% vs. 2.7%). Levels of Treponema denticola, Prevotella nigrescens, and Streptococcus mitis were significantly associated with severe periodontitis. We demonstrated the feasibility of detecting periopathogenic bacteria in mouth-rinse samples obtained from patients with periodontitis. As we did not comprehensively assess all periopathogenic bacteria, further studies are required to assess the potential of oral-rinsing solutions to indicate oral infection risk and the need to improve oral hygiene, and to serve as a complementary method for periodontal disease diagnosis.

Adjunctive Antiseptic Irrigation of Periodontal Pockets: Effects on Microbial and Cytokine Profiles

To evaluate the effect of adjunctive antiseptic irrigation of periodontal pockets on microbial and cytokine profiles. Fifty-nine patients with severe periodontitis were allocated to one of three groups for scaling and root planing facilitated with different adjunctive antiseptics: 1% polyhexamethyleneguanidine phosphate (PHMG-P) (n = 19), 0.2% chlorhexidine (CHX) (n = 21) or distilled water (n = 19). Gingival crevicular fluid and subgingival bacterial samples were collected at baseline, and at 2 weeks, and 1 and 4 months. The levels of interleukin (IL)-1β, IL-8, IL-10, and IL-17A, matrix metalloproteinase (MMP)-8, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum,Aggregatibacter actinomycetemcomitans, and Prevotella intermedia were determined. There were no intergroup differences in cytokine concentrations and bacterial counts at any follow-up, however, varying patterns were observed. In the PHMG-P and water groups IL-1β expression peaked at 2 weeks and then gradually declined. In all three groups, the dynamics of MMP-8 concentration were non-linear, increasing by 2 weeks and then declining to below baseline (p > 0.05). P. gingivalis and T. forsythia declined within the first month and increased thereafter, not regaining the baseline level. Adjunctive antiseptic treatment was associated with changes in biomarkers and bacterial counts in the course of the study. The effects of adjunctive antiseptic irrigation were limited in the applied protocol.

The combined use of salivary biomarkers and clinical parameters to predict the outcome of scaling and root planing: A cohort study

AIM

To explore the application of the combined use of baseline salivary biomarkers and clinical parameters in predicting the outcome of scaling and root planing (SRP).

MATERIALS AND METHODS

Forty patients with advanced periodontitis were included. Baseline saliva samples were analysed for interleukin-1β (IL-1β), matrix metalloproteinase-8 and the loads of Porphyromonas gingivalis, Prevotella intermedia, Aggregatibacter actinomycetemcomitans and Tannerella forsythia. After SRP, pocket closure and further attachment loss at 6 months post-treatment were chosen as outcome variables. Models to predict the outcomes were established by generalized estimating equations.

RESULTS

The combined use of baseline clinical attachment level (CAL), site location and IL-1β (area under the curve [AUC] = 0.764) better predicted pocket closure than probing depth (AUC = 0.672), CAL (AUC = 0.679), site location (AUC = 0.654) or IL-1β (AUC = 0.579) alone. The combination of site location, tooth loss, percentage of deep pockets, detection of A. actinomycetemcomitans and T. forsythia load (AUC = 0.842) better predicted further clinical attachment loss than site location (AUC = 0.715), tooth loss (AUC = 0.530), percentage of deep pockets (AUC = 0.659) or T. forsythia load (AUC = 0.647) alone.

CONCLUSION

The combination of baseline salivary biomarkers and clinical parameters better predicted SRP outcomes than each alone. The current study indicates the possible usefulness of salivary biomarkers in addition to tooth-related parameters in predicting SRP outcomes.

Serum lipopolysaccharide neutralizing capacity in ischemic stroke

Introduction

Periodontitis is associated with increased serum lipopolysaccharide (LPS) activity, which may be one mechanism linking periodontitis with the risk of cardiovascular diseases. As LPS-carrying proteins including lipoproteins modify LPS-activity, we investigated the determinants of serum LPS-neutralizing capacity (LPS-NC) in ischemic stroke. The association of LPS-NC and Aggregatibacter actinomycetemcomitans, a major microbial biomarker in periodontitis, was also investigated.

Materials and methods

The assay to measure LPS-NC was set up by spiking serum samples with E. coli LPS. The LPS-NC, LPS-binding protein (LBP), soluble CD14 (sCD14), lipoprotein profiles, apo(lipoprotein) A-I, apoB, and phospholipid transfer protein (PLTP) activity, were determined in 98 ischemic stroke patients and 100 age- and sex-matched controls. Serum and saliva immune response to A. actinomycetemcomitans, its concentration in saliva, and serotype-distribution were examined.

Results

LPS-NC values ranged between 51–83% in the whole population. Although several of the LPS-NC determinants differed significantly between cases and controls (PLTP, sCD14, apoA-I, HDL-cholesterol), the levels did not (p = 0.056). The main determinants of LPS-NC were i) triglycerides (β = -0.68, p<0.001), and ii) HDL cholesterol (0.260, <0.001), LDL cholesterol (-0.265, <0.001), PLTP (-0.196, 0.011), and IgG against A. actinomycetemcomitans (0.174, 0.011). Saliva A. actinomycetemcomitans concentration was higher [log mean (95% CI), 4.39 (2.35–8.19) vs. 10.7 (5.45–21) genomes/ml, p = 0.023) and serotype D more frequent (4 vs. 0%, p = 0.043) in cases than controls. Serotypeablity or serotypes did not, however, relate to the LPS-NC.

Conclusion

Serum LPS-NC comprised low PLTP-activity, triglyceride and LDL cholesterol concentrations, as well as high HDL cholesterol and IgG against A. actinomycetemcomitans. The present findings let us to conclude that LPS-NC did not associate with stroke.

Gingival tissue human beta-defensin levels in relation to infection and inflammation

AIM

To profile gingival tissue levels of human beta-defensin (hBD)-2 and hBD-3 in relation to gingival inflammation, Th17-related cytokine concentrations, Porphyromonas gingivalis counts, and gingipain and total protease activities.

MATERIALS AND METHODS

Gingival tissue and subgingival plaque samples were collected from 21 periodontitis patients including 48 periodontal pocket sites with marginal, mild, or moderate to severe inflammation. hBD levels were determined by immunodetection, P. gingivalis counts with real-time polymerase chain reaction, protease activities with fluorogenic substrates, and cytokine concentrations with Luminex technique. Data were statistically analysed using Kruskal-Wallis and Mann-Whitney U tests and Spearman correlation coefficients.

RESULTS

Subgingival plaque counts of P. gingivalis (p = .001) and gingipain activity (p < .001), as well as interleukin (IL)-1β (p = .012), IL-10 (p = .024), IL-17A (p = .002), IL-17F (p = .006), and IL-23 (p = .036) concentrations were elevated in severely inflamed sites, whereas no change was observed in hBD-2 and hBD-3 levels. Negative correlations were found between protease activity and hBD-2 (p = .033) and hBD-3(p = .003) levels.

CONCLUSIONS

Shift in gingival inflammation from marginal to mild stage is related to elevations in subgingival plaque P. gingivalis counts and gingipain activity, but not to tissue hBD levels. Negative correlations between hBDs and total protease activity suggest the degradation of these antimicrobial peptides in progressed inflammation.

Salivary Cytokine Biomarker Concentrations in Relation to Obesity and Periodontitis

Systemic low-grade inflammation is associated with obesity. Our aim was to examine the association between obesity and salivary biomarkers of periodontitis. Salivary interleukin (IL)-1-receptor antagonist (IL-1Ra), IL-6, IL-8, IL-10, and tumor necrosis factor (TNF)-α concentrations were measured from 287 non-diabetic obese (body mass index (BMI) of >35 kg/m²) individuals and 293 normal-weight (BMI of 18.5–25 kg/m²) controls. Periodontal status was defined according to a diagnostic cumulative risk score (CRS) to calculate the risk of having periodontitis (CRS I, low risk; CRS II, medium risk; CRS III, high risk). In the whole population, and especially in smokers, higher IL-8 and lower IL-10 concentrations were detected in the obese group compared to the control group, while in non-smoking participants, the obese and control groups did not differ. IL-1Ra and IL-8 concentrations were higher in those with medium or high risk (CRS II and CRS III, p < 0.001) of periodontitis, whereas IL-10 and TNF-α concentrations were lower when compared to those with low risk (CRS I). In multivariate models adjusted for periodontal status, obesity did not associate with any salivary cytokine concentration. In conclusion, salivary cytokine biomarkers are not independently associated with obesity and concentrations are dependent on periodontal status.

Microbial changes in biofilms on composite resins with different surface roughness: An in vitro study with a multispecies biofilm model

STATEMENT OF PROBLEM

The single-species biofilm method cannot represent the interaction and complex functions of microorganisms associated with oral biofilms.

PURPOSE

The purpose of this in vitro study was to investigate microbial changes in biofilms on composite resins of varying surface roughness by using a multispecies biofilm model with early-colonizing streptococci, middle colonizer, and late-colonizing gram-negative anaerobes.

MATERIAL AND METHODS

Composite resin disks were prepared with different roughness: SR180, SR400, SR1500, and SRGlass roughened with 180-, 400-, and 1500-grit silicon carbide paper and glass (control surface without surface roughening). Surface roughness was analyzed by confocal laser scanning and scanning electron microscopy. After multispecies biofilms had been grown on the composite resin surfaces, the adhesion of Streptococcus mutans, Streptococcus sobrinus, Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and of total bacteria was determined after 1 (T1) and 4 (T2) days. Differences in surface roughness among the 4 groups were tested with 1-way ANOVA. Multifactorial analysis of variance was used to determine the time-related differences in the bacterial composition with respect to surface roughness (α=.05).

RESULTS

The order of SR, from highest to lowest, was SR180 (1.45 ±0.11 μm), SR400 (0.62 ±0.05 μm), SR1500 (0.35 ±0.02 μm), and SRGlass (0.15 ±0.01 μm) (SR180>SR400>SR1500>SRGlass, P<.001). Increased surface roughness was not proportional to bacterial adhesion. Significant differences in the adhesion of total bacteria was only found between SRGlass and SR180 (SR180>SRGlass, P=.029). The adhesion of S. mutans and S. sobrinus to SR180 and SR400 was higher than that to SRGlass (SR180=SR400>SRGlass; S. mutans, P=.003; S. sobrinus, P=.002). However, the adhesion of A. actinomycetemcomitans and P. gingivalis to composite resin was not significantly influenced by surface roughness. Adhesion of total bacteria, S. mutans, and S. sobrinus increased from T1 to T2 (T1<T2, P<.001), whereas the adhesion of periodontal pathogens decreased from T1 to T2 (T1>T2; A. actinomycetemcomitans, P<.001; P. gingivalis, P=.013).

CONCLUSIONS

Decreased adhesion of cariogenic streptococci and total bacteria was observed at surface roughness values of around 0.15 μm. Periodic finishing of surface roughness should be considered to minimize the adhesion of cariogenic streptococci to composite resin surfaces.

Selective bacterial degradation of the extracellular matrix attaching the gingiva to the tooth

The junctional epithelium (JE) is a specialized portion of the gingiva that seals off the tooth‐supporting tissues from the oral environment. This relationship is achieved via a unique adhesive extracellular matrix that is, in fact, a specialized basal lamina (sBL). Three unique proteins – amelotin (AMTN), odontogenic ameloblast‐associated (ODAM), and secretory calcium‐binding phosphoprotein proline‐glutamine rich 1 (SCPPPQ1) – together with laminin‐332 structure the supramolecular organization of this sBL and determine its adhesive capacity. Despite the constant challenge of the JE by the oral microbiome, little is known of the susceptibility of the sBL to bacterial degradation. Assays with trypsin‐like proteases, as well as incubation with Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola, revealed that all constituents, except SCPPPQ1, were rapidly degraded. Porphyromonas gingivalis was also shown to alter the supramolecular network of reconstituted and native sBLs. These results provide evidence that proteolytic enzymes and selected gram‐negative periodontopathogenic bacteria can attack this adhesive extracellular matrix, intimating that its degradation could contribute to progression of periodontal diseases.

BAX Gene Overexpression in the Tongue Could Warn of Infection Risk due to Periodontal Pathogens

Background:

Different host proteins play a central role in cell response during bacterial infections, the Bcl-2-Associated X protein (BAX) and Vascular Cell Adhesion Protein 1 (VCAM-1) are often reported in infective primary events during cell injury.

Objective:

The aim of this study is to evaluate the predictive value of these two proteins as biomarkers of oral bacterial infection, with particular emphasis on the tongue, which plays an important role in microbial homeostasis in the mouth.

Methods:

Twenty-nine patients were recruited and divided according to the Periodontal Index (CPI), 4 of them were severely compromised periodontal patients. Oral hygiene, gingival tissues and plaque presence were evaluated clinically. The laboratory analysis carried out on tongue tissue included: total bacterial genomes, proportion of specific periopathogens and BAX -VCAM-1 expression rate, while Reactive Oxygen Species (ROS) were measured in saliva.

Results:

Neither tongue microbiological status nor salivary ROS level corresponded with the state of disease. VCAM-1 mRNA expression rate was comparable in all patients but, on the contrary, BAX expression resulted high in periodontally-compromised patients and appears related to periodontal status in the analyzed subjects.

Conclusion:

This preliminary work suggests that the BAX protein is a possible candidate in a prognostic marker study for oral diseases started by periodontal bacteria. For example, none of the evaluated clinical and microbiological parameters could predict the presence, prognosis or recurrence of periodontal diseases. This biomarker could be a valuable tool in determining the risk, diagnosis and prognosis of this human illness.

Molecular forms and fragments of salivary MMP-8 in relation to periodontitis

AIM

To investigate the molecular forms of salivary matrix metalloproteinase (MMP)-8 in relation to periodontitis.

MATERIALS AND METHODS

Molecular forms, degree of activation and fragmentation of neutrophilic and mesenchymal-type MMP-8 isoforms were analysed from salivary samples of 81 subjects with generalized periodontitis, 63 subjects with localized periodontitis and 79 subjects without pocket teeth, by using western-immunoblots with computer quantitation. In addition, human recombinant proMMP-8 was in vitro activated by Treponema denticola chymotrypsin-like protease (Td-CTLP), sodium hypochlorite (NaOCl, 1 mM, oxidant) or amino phenyl mercuric acetate (APMA, 1 mM).

RESULTS

In saliva of periodontitis-affected individuals, MMP-8 is found in multiple forms, that is, complexes, active and pro-forms of neutrophilic and mesenchymal-type MMP-8, and especially 20-27 kDa fragments. The quantity of these fragments was elevated in both localized and generalized forms of periodontitis. Moreover, the tested activators (Td-CTLP, NaOCl and APMA) activated inactive proMMP-8, resulting in fragments of 20-27 kDa, in vitro, and salivary concentrations of T. denticola correlated significantly with salivary levels of fragmented MMP-8.

CONCLUSION

The present results indicate that during the development and progression of periodontitis, MMP-8 appears as activated and fragmented, and treponemal proteases most likely play role in this cascade.

Cumulative use of salivary markers with an adaptive design improves detection of periodontal disease over fixed biomarker thresholds

OBJECTIVE

Aim was to analyze the diagnostic ability of cumulative risk score (CRS), which uses salivary levels of Porphyromonas gingivalis, interleukin (IL)-1β, and matrix metalloproteinase (MMP)-8 in an adaptive design, compared to previously reported thresholds of each marker alone.

MATERIALS AND METHODS

Oral and general health information of 463 participants were included in the analysis. Having the percentage of bleeding on probing (BOP) > 25%, having at least two sites with probing pocket depth (PPD) of 4-5 mm or having at least one tooth with alveolar bone loss (ABL) of at least 1/3 of the root length were accepted as outcome variables. Being above the salivary threshold concentrations of P. gingivalis, IL-1β, and MMP-8 and CRS values were used as explanatory variables. Receiver operating characteristics (ROC) producing an area under the curve (AUC) and multinomial regression analysis were used in statistical analysis.

RESULTS

CRS provided AUCs larger than any other tested biomarker threshold. Sensitivity and specificity of CRS for detecting clinical markers of periodontitis were acceptable, and a strong association was observed between the highest CRS score and having at least two sites with PPD of 4-5 mm.

CONCLUSION

CRS brings additional power over fixed thresholds of single biomarkers in detecting periodontitis.

Real-time PCR quantification of 9 periodontal pathogens in saliva samples from periodontally healthy Korean young adults

Purpose

Few studies have examined periodontal pathogens from saliva samples in periodontally healthy young adults. The purposes of this study were to determine the prevalence of periodontopathic bacteria and to quantify periodontal pathogens in saliva samples using real-time polymerase chain reaction (PCR) assays in periodontally healthy Korean young adults under 35 years of age.

Methods

Nine major periodontal pathogens were analyzed by real-time PCR in saliva from 94 periodontally healthy young adults. Quantification of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Fusobacterium nucleatum, Campylobacter rectus, Peptostreptococcus anaerobius, and Eikenella corrodens was performed by DNA copy number measurement.

Results

F. nucleatum and E. corrodens were detected in all subjects; the numbers of positive samples were 87 (92.6%), 91 (96.8%), and 90 (95.7%) for P. gingivalis, P. anaerobius, and C. rectus, respectively. Other pathogens were also detected in periodontally healthy subjects. Analysis of DNA copy numbers revealed that the most abundant periodontal pathogen was F. nucleatum, which was significantly more prevalent than all other bacteria (P<0.001), followed by P. anaerobius, P. gingivalis, E. corrodens, C. rectus, and T. denticola. There was no significant difference in the prevalence of each bacterium between men and women. The DNA copy number of total bacteria was significantly higher in men than in women.

Conclusions

Major periodontal pathogens were prevalent in the saliva of periodontally healthy Korean young adults. Therefore, we suggest that the development of periodontal disease should not be overlooked in periodontally healthy young people, as it can arise due to periodontal pathogen imbalance and host susceptibility.

Relationship between the burden of major periodontal bacteria and serum lipid profile in a cross-sectional Japanese study

Background

The association of periodontal bacteria with lipid profile alteration remains largely unknown, although it has been suggested that chronic periodontitis increases the atherosclerotic risk. This cross-sectional study investigated the relationship between the prevalence and total burden of periodontal bacteria and serum lipid profile.

Methods

Saliva from enrolled participants was collected to detect 4 major periodontal bacteria (Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Prevotella intermedia) using Polymerase Chain Reaction method. High-density lipoprotein (HDL) cholesterol, triglycerides (TG), and low-density lipoprotein cholesterol were assessed using blood samples. We compared the averages of each lipid in association with the prevalence of each bacterial species, their burden (low, moderate, and high), and the combination of bacterial burden and periodontal status, defined as periodontitis, using the Community Periodontal Index, after adjustment for other potential confounding factors, by employing general linear models with least square means.

Results

A total of 385 Japanese individuals (176 men, 209 women; mean age 69.2 years) were enrolled. The number of bacterial species and their co-existence with periodontitis were significantly related to a decrease in HDL (p for trend < 0.01) and increase in TG (p for trend = 0.04). The adjusted mean HDL levels (mg/dL) in individuals with low, moderate, and high levels of bacterial species were 66.1, 63.0, and 58.9, respectively, and those in the 6 groups defined by combination of the two factors were 67.9, 64.6, 64.3, 65.4, 61.5, and 54.7, respectively.

Conclusion

Periodontal bacterial burden is suggested to be independently involved in lowering serum HDL level. Our findings suggest that bacterial tests in a clinical setting could be a useful approach for predicting the risk of HDL metabolism dysregulation.

Immunoglobulin G antibodies against Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans in cardiovascular disease and periodontitis

Objectives: The aim was to elucidate whether levels of circulating antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis correlate to loss of attachment, as a marker for periodontitis and cardiovascular disease (CVD). Design: Sera were collected from 576 participants of the Danish Health Examination Survey (DANHES). Immunoglobulin G antibodies against lipopolysaccharide (LPS) and protein antigens from the a, b and c serotypes of A. actinomycetemcomitans and P. gingivalis were quantified by titration in ELISA plates coated with a mixture of antigens prepared by disintegration of bacteria. Results: Levels of antibodies against P. gingivalis (OR = 1.48) and A. actinomycetemcomitans (1.31) associated with periodontitis, as determined by univariable logistic regression analysis. These antibody levels also associated with CVD (1.17 and 1.37), respectively, However, after adjusting for other risk factors, including age, smoking, gender, alcohol consumption, overweight, and level of education using multivariable logistic regression analysis, only increasing body mass index (BMI; 1.09), previous smoking (1.99), and increasing age (decades) (2.27) remained associated with CVD. Increased levels of antibodies against P. gingivalis (1.34) remained associated with periodontitis after adjusting for other risk factors. Conclusions: CVD and periodontitis were associated with levels of IgG antibodies to P. gingivalis or A. actinomycetemcomitans in univariable analyses, but only the association of P. gingivalis antibody levels with periodontitis reached statistical significance after adjustment for common confounders. Age, in particular, influenced this relationship.

Cross-reactive saliva IgA antibodies to oxidized LDL and periodontal pathogens in humans

AIM

Oxidized low-density lipoproteins (oxLDL) are formed as a result of lipid peroxidation and are highly immunogenic and proatherogenic. In this study, saliva antibodies binding to oxLDL, Porphyromonas gingivalis (Pg) and Aggregatibacter actinomycetemcomitans (Aa) were characterized and their cross-reactivity was evaluated.

MATERIALS AND METHODS

Resting and stimulated saliva samples were collected from 36 healthy adults (mean age 26 years). Saliva IgA, IgG and IgM autoantibody levels to copper oxidized LDL (CuOx-LDL) and malondialdehyde acetaldehyde-modified LDL (MAA-LDL) were determined with chemiluminescence immunoassay.

RESULTS

Saliva IgA and IgG antibodies binding to MAA-LDL and CuOx-LDL were detected in all samples and they were associated with the saliva levels of IgA and IgG to P. gingivalis and A. actinomycetemcomitans. Competitive immunoassay showed that saliva antibodies to MAA-LDL cross-reacted specifically with P. gingivalis. The autoantibody levels to oxLDL in saliva were not associated with the autoantibody levels to oxLDL in plasma or with saliva apolipoprotein B 100 levels.

CONCLUSIONS

Saliva contains IgA and IgG binding to oxLDL, which showed cross-reactive properties with the periodontal pathogens Porphyromonas gingivalis (P.g). The data suggest that secretory IgA to P.g may participate in immune reactions involved in LDL oxidation through molecular mimicry.

Mannose-binding lectin gene polymorphism in relation to periodontal infection

BACKGROUND AND OBJECTIVE

Mannose-binding lectin (MBL) plays an important role in innate immunity. MBL deficiency is usually caused by mutations in exon 1 of the MBL structural gene (MBL2). Our aim was to investigate MBL2 polymorphisms and their relation to salivary levels of periodontal inflammatory/tissue destruction markers and two major periodontitis-associated bacteria.

MATERIAL AND METHODS

Salivary samples from 222 subjects were available for genotyping by pyrosequencing. The subjects between 40 and 60 years of age and having a minimum of 20 teeth were divided into three periodontal groups: 80 had generalized periodontitis, 65 had localized periodontitis and 77 were periodontitis-free. A comparison between their MBL2 genotypes and salivary detection rates and levels of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis as well as interleukin -1β, matrix metalloproteinase -8, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 was performed.

RESULTS

The frequencies of the MBL2 wild-type (A/A), heterozygote variants (A/O) and homozygote variants (O/O) were 69.4%, 26.6% and 4%, respectively. In A. actinomycetemcomitans-positive subjects having homozygote or heterozygote MBL2 variants, the salivary concentrations of IL-1β (p = 0.010) were elevated and those of TIMP-1 (p = 0.001) were decreased. In addition their matrix metalloproteinase -8/TIMP-1 ratio was higher (p < 0.001) and they had more pocket teeth (p = 0.012) than subjects negative for A. actinomycetemcomitans.

CONCLUSION

Our findings indicate that the carriage of A. actinomycetemcomitans may facilitate extended periodontal inflammation and destruction in subjects with a variant form of human MBL2.

[Gender-related marker pathogens of periodontal disease in chronic periodontitis]

By using qPCR system, women as well as men were found to have an equal periodontal pathogen colonization. However, the women are subjected to have a higher risk of chronic periodontitis onsets. Women with the chronic periodontitis usually expose an evident hypercolonization with a single pathogen. P. gingivalis is the most prevalent causative agent of the chronic periodontitis in women but not in men. In health as well as in the chronic periodontitis a complex of periodontal pathogens forms such as P. gingivalis, P. intermedia, T. forsythensis and T. denticola. T. forsythensis demonstrates the highest correlation with the chronic periodontitis onset in men. Our data allow us to prove T. forsythensis playing the key role in the forming of periodontal pathogen complex.

Salivary IL-1β and red complex bacteria as predictors of the inflammatory status in sub-peri-implant niches of subjects with peri-implant mucositis

BACKGROUND AND OBJECTIVES

Salivary biomarkers may enhance diagnostic sensitivity for peri-implant disease assessment. This study aimed to investigate the association of salivary periodontopathogen count and salivary interleukin-1beta (IL-1β) level with the peri-implant crevicular fluid IL-1β response at peri-implant mucositis (PM) sites among subjects with differing periodontal disease susceptibility.

MATERIALS AND METHODS

Eighty-seven partially edentulous subjects having at least one implant with peri-implant mucositis were included: 40 with history of chronic periodontitis (P) and 47 with no history of periodontitis (NP). Salivary IL-1β, peri-implant crevicular fluid (PICF) IL-1β, and salivary red complex pathogen counts were recorded. Subjects were scored according to a threshold salivary pathogen level of more than 5log (10) counts and assigned a "red complex score." Quartiles of salivary and PICF IL-1β levels were also scored. Area under receiver operating curve (AUC) was computed to predict the highest PICF IL-1β score using salivary biomarker as predictors and age-adjusted logistic regression performed for the significant predictors.

RESULTS

In the NP group, red complex score (AUC = 0.758 P = 0.010) (odds ratio = 1.377) and salivary IL-1β (AUC = 0.708 P = 0.038) (odds ratio = 2.506) were significant predictors of highest PICF IL-1β quartile score. In the P group, no significant associations were noted.

CONCLUSIONS

Salivary biomarkers could distinguish the "high" pro-inflammatory responders at PM sites only in subjects without inherent periodontal disease susceptibility. Periodontal susceptibility may impact the immuno-inflammatory response in sub-peri-implant niches of those with peri-implant mucositis.

Quantitative PCR analysis of salivary pathogen burden in periodontitis

Our aim was to investigate the value of salivary concentrations of four major periodontal pathogens and their combination in diagnostics of periodontitis. The Parogene study included 462 dentate subjects (mean age 62.9 ± 9.2 years) with coronary artery disease (CAD) diagnosis who underwent an extensive clinical and radiographic oral examination. Salivary levels of four major periodontal bacteria were measured by quantitative real-time PCR (qPCR). Median salivary concentrations of Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, as well as the sum of the concentrations of the four bacteria, were higher in subjects with moderate to severe periodontitis compared to subjects with no to mild periodontitis. Median salivary Aggregatibacter actinomycetemcomitans concentrations did not differ significantly between the subjects with no to mild periodontitis and subjects with moderate to severe periodontitis. In logistic regression analysis adjusted for age, gender, diabetes, and the number of teeth and implants, high salivary concentrations of P. gingivalis, T. forsythia, and P. intermedia were significantly associated with moderate to severe periodontitis. When looking at different clinical and radiographic parameters of periodontitis, high concentrations of P. gingivalis and T. forsythia were significantly associated with the number of 4-5 mm periodontal pockets, ≥6 mm pockets, and alveolar bone loss (ABL). High level of T. forsythia was associated also with bleeding on probing (BOP). The combination of the four bacteria, i.e., the bacterial burden index, was associated with moderate to severe periodontitis with an odds ratio (OR) of 2.40 (95% CI 1.39-4.13). When A. actinomycetemcomitans was excluded from the combination of the bacteria, the OR was improved to 2.61 (95% CI 1.51-4.52). The highest OR 3.59 (95% CI 1.94-6.63) was achieved when P. intermedia was further excluded from the combination and only the levels of P. gingivalis and T. forsythia were used. Salivary diagnostics of periodontitis has potential especially in large-scale population studies and health promotion. The cumulative strategy appears to be useful in the analysis of salivary bacteria as markers of periodontitis.

Intraspecies Variability Affects Heterotypic Biofilms of Porphyromonas gingivalis and Prevotella intermedia: Evidences of Strain-Dependence Biofilm Modulation by Physical Contact and by Released Soluble Factors

It is well known that strain and virulence diversity exist within the population structure of Porphyromonas gingivalis. In the present study we investigate intra- and inter-species variability in biofilm formation of Porphyromonas gingivalis and partners Prevotella intermedia and Prevotella nigrescens. All strains tested showed similar hydrophobicity, except for P. gingivalis W83 which has roughly half of the hydrophobicity of P. gingivalis ATCC33277. An intraspecies variability in coaggregation of P. gingivalis with P. intermedia was also found. The association P. gingivalis W83/P. intermedia 17 produced the thickest biofilm and strain 17 was prevalent. In a two-compartment system P. gingivalis W83 stimulates an increase in biomass of strain 17 and the latter did not stimulate the growth of P. gingivalis W83. In addition, P. gingivalis W83 also stimulates the growth of P. intermedia ATCC25611 although strain W83 was prevalent in the association with P. intermedia ATCC25611. P. gingivalis ATCC33277 was prevalent in both associations with P. intermedia and both strains of P. intermedia stimulate the growth of P. gingivalis ATCC33277. FISH images also showed variability in biofilm structure. Thus, the outcome of the association P. gingivalis/P. intermedia seems to be strain-dependent, and both soluble factors and physical contact are relevant. The association P. gingivalis-P. nigrescens ATCC33563 produced larger biomass than each monotypic biofilm, and P. gingivalis was favored in consortia, while no differences were found in the two-compartment system. Therefore, in consortia P. gingivalis-P. nigrescens physical contact seems to favor P. gingivalis growth. The intraspecies variability found in our study suggests strain-dependence in ability of microorganisms to recognize molecules in other bacteria which may further elucidate the dysbiosis event during periodontitis development giving additional explanation for periodontal bacteria, such as P. gingivalis and P. intermedia, among others, to persist and establish chronic infections in the host.

Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Treponema denticola / Prevotella intermedia Co-Infection Are Associated with Severe Periodontitis in a Thai Population

Periodontitis is a polymicrobial infection of tooth-supporting tissues. This cross-sectional study aimed to examine the associations between five target species and severe periodontitis in a Thai population. Using the CDC/AAP case definition, individuals diagnosed with no/mild and severe periodontitis were included. Quantitative analyses of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Treponema denticola (Td), and Prevotella intermedia (Pi) in subgingival plaque were performed using real-time polymerase chain reaction. The association between target species and severe periodontitis was examined using logistic regression analysis. The study subjects comprised 479 individuals with no/mild periodontitis and 883 with severe periodontitis. Bacterial prevalence and quantity were higher in subjects with severe periodontitis than in those with no/mild disease. In the fully adjusted model, all species except Tf showed a dose-dependent relationship with periodontitis. The mere presence of Pg, even in low amount, was significantly associated with severe periodontitis, while the amount of Aa, Td, and Pi had to reach the critical thresholds to be significantly associated with disease. Compared to individuals with low levels of both Td and Pi, high colonization by either Td or Pi alone significantly increased the odds of having severe periodontitis by 2.5 (95%CI 1.7-3.5) folds. The odds ratio was further increased to 14.8 (95%CI 9.2-23.8) in individuals who were highly colonized by both species. Moreover, the presence of Pg and high colonization by Aa were independently associated with severe periodontitis with odds ratios of 5.6 (95%CI 3.4-9.1) and 2.2 (95%CI 1.5-3.3), respectively. Our findings suggest that the presence of Pg and high colonization by Aa, Td, and Pi play an important role in severe periodontitis in this study population. We also demonstrate for the first time that individuals co-infected with Td and Pi were more likely to have periodontitis than were those infected with a single pathogen.

Real-time PCR quantification of six periodontal pathogens in saliva samples from healthy young adults

OBJECTIVE

The use of saliva as a diagnostic fluid for the evaluation of periodontal health has gained attention recently. Most published real-time PCR assays focused on quantification of bacteria in subgingival plaque, not in saliva. The aims of this study were to develop a real-time PCR assay for quantification of six periodontal pathogens in saliva and to establish a relationship between the amount of DNA (fg) and colony-forming unit (CFU).

MATERIALS AND METHODS

TaqMan primers/probe sets were used for the detection of Aggregatibacter actinomycetemcomitans (Aa), Eikenella corrodens (Ec), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), Tannerella forsythia (Tf), and total bacteria. Six periodontal pathogens and total bacteria in saliva from 24 periodontally healthy individuals were determined. The relationship between the amount of DNA (fg) and CFU was established by measuring the concentrations of extracted bacterial DNA and CFU per milliliter of bacteria on agar plates.

RESULTS

Fn, Ec, and Pi were detected in all saliva samples, while 58.5, 45.8, and 33.3% were detected for Tf, Pg, and Aa, respectively. Numbers of Ec and Fn in saliva were highly correlated (R(2) = 0.93, P < 0.01). The values of DNA (fg) per CFU ranged from 64 for Ec to 121 for Pg.

CONCLUSION

The real-time PCR assay in combination with the relationship between DNA (fg) and CFU can be used to quantitate periodontal pathogens in saliva and estimate the number of live bacteria (CFU).

CLINICAL RELEVANCE

This real-time PCR assay in combination with the relationship between DNA (fg) and CFU has the potential to be an adjunct in evaluation of periodontal health status.

Evaluation of a new oral health scale of infectious potential based on the salivary microbiota

OBJECTIVES

The objective of this study is to analyse the correlation of our own design of oral health scale (grades 0 and 1-better oral health vs. grades 2 and 3-poorer oral health) with the salivary microbiota.

PATIENTS AND METHODS

The oral health scale we elaborated was evaluated in 100 adults (25 patients from each global oral health grade). Saliva samples collected from these patients were analysed using microbiological culture techniques, determining the presence/absence and the concentrations of some odontopathogens and periodontopathogens.

RESULTS

In comparison with the global oral health grades 0-1, the grades 2-3 presented significantly higher values for the presence of odontopathogens (78 vs. 38 %; Streptococcus mutans, Lactobacillus spp. and Actinomyces spp.) and periodontopathogens (100 vs. 90 %; Aggregatibacter actinomycetemcomitans, Campylobacter spp., Fusobacterium spp. and Prevotella gingivalis). In comparison with the grades 0-1, the grades 2-3 presented significantly higher values for the concentrations (CFU/mL log10) of facultative anaerobes, strict anaerobes, odontopathogens (S. mutans, Lactobacillus spp. and Actinomyces spp.) and periodontopathogens (A. actinomycetemcomitans, Capnocytophaga spp., Campylobacter spp. and Fusobacterium spp.).

CONCLUSION

Our new global oral health scale shows a positive correlation with the detection and quantification of certain odontopathogens and periodontopathogens present in the saliva, confirming their possible infectious potential.

CLINICAL RELEVANCE

Our own design of oral health scale could be particularly useful for the epidemiological study of different populations, the evaluation of the influence of oral health on the development of certain systemic diseases as well as the analysis of inter- and intra-individual variability of the oral microbiota in relation to the different grades of the oral health scale.

Quantitative molecular detection of putative periodontal pathogens in clinically healthy and periodontally diseased subjects

Periodontitis is a multi-microbial oral infection with high prevalence among adults. Putative oral pathogens are commonly found in periodontally diseased individuals. However, these organisms can be also detected in the oral cavity of healthy subjects. This leads to the hypothesis, that alterations in the proportion of these organisms relative to the total amount of oral microorganisms, namely their abundance, rather than their simple presence might be important in the transition from health to disease. Therefore, we developed a quantitative molecular method to determine the abundance of various oral microorganisms and the portion of bacterial and archaeal nucleic acid relative to the total nucleic acid extracted from individual samples. We applied quantitative real-time PCRs targeting single-copy genes of periodontal bacteria and 16S-rRNA genes of Bacteria and Archaea. Testing tongue scrapings of 88 matched pairs of periodontally diseased and healthy subjects revealed a significantly higher abundance of P. gingivalis and a higher total bacterial abundance in diseased subjects. In fully adjusted models the risk of being periodontally diseased was significantly higher in subjects with high P. gingivalis and total bacterial abundance. Interestingly, we found that moderate abundances of A. actinomycetemcomitans were associated with reduced risk for periodontal disease compared to subjects with low abundances, whereas for high abundances, this protective effect leveled off. Moderate archaeal abundances were health associated compared to subjects with low abundances. In conclusion, our methodological approach unraveled associations of the oral flora with periodontal disease, which would have gone undetected if only qualitative data had been determined.

Progression of periodontal inflammation in adolescents is associated with increased number of Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Fusobacterium nucleatum

OBJECTIVE

The study aims to evaluate the change of related subgingival periodontopathogens among different stage of gingivitis in adolescent and assess the relationship between periodontopathogens and the progression of periodontal inflammation.

METHODS

A total of 77 subgingival plaque samples from 35 adolescent individuals were divided into three groups including gingivitis group (mild, 15 samples; moderate, 16 samples; severe, 15 samples), chronic periodontitis group (15 samples) and healthy group (15 samples). Real-time PCR was used to quantitate Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythensis, and Fusobacterium nucleatum in subgingival plaque samples.

RESULTS

All species, except for F. nucleatum, were detected in samples from gingivitis and periodontitis groups in significantly greater number than in those from healthy group (P < 0.05). In gingivitis groups, the number of P. gingivalis, T. forsythensis, and F. nucleatum in moderate and severe gingivitis groups was significantly higher than in mild gingivitis group (P < 0.05). After merging moderate gingivitis and severe gingivitis groups into moderate-to-severe gingivitis group, the four periodontopathogens were detected in samples from periodontitis group in significantly greater number than in those from moderate-to-severe gingivitis group (P < 0.05).

CONCLUSION

The number of P. gingivalis, P. intermedia, T. forsythensis, and F. nucleatum in subgingival plaque increases with progression of periodontal inflammation in adolescents. Examination of periodontopathogens number in adolescents may be of some value for monitoring of periodontal disease development.

Salivary biomarkers of bacterial burden, inflammatory response, and tissue destruction in periodontitis

AIM

Chronic periodontitis has an episodic and multifactorial character, with fluctuations in bacterial burden, inflammatory response, and tissue destruction. We investigated the association of selected salivary biomarkers with periodontal parameters and validated the use of a novel salivary diagnostic approach, the cumulative risk score (CRS), in detection of periodontitis in subjects with angiographically verified coronary artery disease diagnosis.

MATERIALS AND METHODS

The concentrations of matrix metalloproteinase (MMP)-8, interleukin (IL)-1β, and Porphyromonas gingivalis were analysed from saliva of 493 subjects. The subjects participated in a detailed clinical and radiographic oral examination. The CRS index, combining the three salivary biomarkers, was calculated for each subject.

RESULTS

High salivary concentrations of MMP-8, IL-1β, and P. gingivalis were associated with deepened periodontal pockets and alveolar bone loss, and MMP-8 and IL-1β with bleeding on probing. The CRS index had a stronger association with moderate to severe periodontitis (OR 6.13; 95% CI 3.11-12.09) than any of the markers alone.

CONCLUSIONS

Salivary concentrations of MMP-8, IL-1β, and P. gingivalis are associated with various clinical and radiographic measures of periodontitis. The CRS index, combining the three salivary biomarkers, is associated with periodontitis more strongly than any of the markers alone regardless of the coronary artery disease status of the patients.

Microbial analysis of subgingival plaque samples compared to that of whole saliva in patients with periodontitis

BACKGROUND

The detection of special bacterial species in patients with periodontitis is considered to be useful for clinical diagnosis and treatment. The collection of subgingival plaque samples is the common way for the determination of periodontopathic bacteria. However, recently, salivary analysis has been discussed as an advantageous future diagnostic method for periodontitis because it offers simple quantitative sampling and the possibility to assess various bacteria. The aim of this cross-sectional study is to investigate whether there is a correlation between the results of different bacterial species in saliva and subgingival plaque samples from individuals with aggressive periodontitis (AgP) and chronic periodontitis (CP).

METHODS

Whole saliva and subgingival plaque samples from the deepest pocket of each quadrant were collected from 43 patients with CP and 33 patients with AgP. Twenty different bacterial species from both samplings were determined by the 16S ribosomal RNA-based polymerase chain reaction with microarray technique.

RESULTS

All bacterial species were detected in salivary and subgingival plaque samples. For Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, as well as Actinomyces viscosus, Campylobacter rectus/showae, Prevotella intermedia, Parvimonas micra, Eubacterium nodatum, and Campylobacter gracilis, a significant positive correlation between salivary and subgingival plaque samples was detected in patients with both types of periodontitis. There were no significant differences in bacteria in salivary and subgingival plaque samples between AgP and CP.

CONCLUSION

Salivary analysis might be discussed as a potential alternative to subgingival plaque sampling for microbiologic analysis in both AgP and CP.

Biomarkers of periodontitis and inflammation in ischemic stroke: A case-control study

Periodontitis is a common infectious disease associated with increased risk for ischemic stroke though presently unclear mechanisms. In a case-control study, we investigated salivary levels of four periodontal pathogens, as well as systemic and local inflammatory markers. The population comprised 98 patients with acute ischemic stroke (mean ± SD, 68.2 ± 9.7 yrs; 45.9% women) and 100 healthy controls (69.1 ± 5.2 yrs; 47.0% women). Patients were more often edentulous and had fewer teeth than controls (13.8 ± 10.8 versus 16.6 ± 10.1). After adjusting for stroke risk factors and number of teeth, controls had higher saliva matrix metalloproteinase-8 (MMP-8), myeloperoxidase (MPO), IL-1β, Aggregatibacter actinomycetemcomitans, and serum LPS activity levels. Patients had higher serum MMP-8 and MPO, and they were more often qPCR-positive for A. actinomycetemcomitans (37.9% versus 19.0%) and for ≥3 periodontopathic species combined (50.0% versus 33.0%). We conclude that controls more often had evidence of current periodontal infection with higher periodontal pathogen amount, endotoxemia, local inflammation and tissue destruction. Stroke patients more often had evidence of end-stage periodontitis with edentulism and missing teeth. They were more often carriers of several periodontopathic pathogens in saliva, especially A. actinomycetemcomitans. Additionally, inflammatory burden may contribute to high systemic inflammation associated with elevated stroke susceptibility.