Periodontal pathogens and associated factors in aggressive periodontitis: results 5-17 years after active periodontal therapy

Therapeutic Strategies and Genetic Implications for Periodontal Disease Management: A Systematic Review

The objective of this review is to identify the microbiological alterations caused by various therapy modalities by critically analyzing the current findings. We limited our search to English-language papers published between 1 January 2004 and 7 May 2024 in PubMed, Scopus, and Web of Science that were relevant to our topic. In the search approach, the Boolean keywords "microbio*" AND "periodontitis" were used. A total of 5152 papers were obtained from the databases Web of Science (2205), PubMed (1793), and Scopus (1154). This resulted in 3266 articles after eliminating duplicates (1886), and 1411 entries were eliminated after their titles and abstracts were examined. The qualitative analysis of the 22 final articles is included in this study. Research on periodontal disease shows that periodontitis alters the oral microbiome and increases antibiotic resistance. Treatments like scaling and root planing (SRP), especially when combined with minocycline, improve clinical outcomes by reducing harmful bacteria. Comprehensive mechanical debridement with antibiotics, probiotics, EMD with bone grafts, and other adjunctive therapies enhances periodontal health. Personalized treatment strategies and advanced microbial analyses are crucial for effective periodontal management and antibiotic resistance control.

Treponema denticola dentilisin triggered TLR2/MyD88 activation upregulates a tissue destructive program involving MMPs via Sp1 in human oral cells

Periodontal disease is driven by dysbiosis in the oral microbiome, resulting in over-representation of species that induce the release of pro-inflammatory cytokines, chemokines, and tissue-remodeling matrix metalloproteinases (MMPs) in the periodontium. These chronic tissue-destructive inflammatory responses result in gradual loss of tooth-supporting alveolar bone. The oral spirochete Treponema denticola, is consistently found at significantly elevated levels in periodontal lesions. Host-expressed Toll-Like Receptor 2 (TLR2) senses a variety of bacterial ligands, including acylated lipopolysaccharides and lipoproteins. T. denticola dentilisin, a surface-expressed protease complex comprised of three lipoproteins has been implicated as a virulence factor in periodontal disease, primarily due to its proteolytic activity. While the role of acylated bacterial components in induction of inflammation is well-studied, little attention has been given to the potential role of the acylated nature of dentilisin. The purpose of this study was to test the hypothesis that T. denticola dentilisin activates a TLR2-dependent mechanism, leading to upregulation of tissue-destructive genes in periodontal tissue. RNA-sequencing of periodontal ligament cells challenged with T. denticola bacteria revealed significant upregulation of genes associated with extracellular matrix organization and degradation including potentially tissue-specific inducible MMPs that may play novel roles in modulating host immune responses that have yet to be characterized within the context of oral disease. The Gram-negative oral commensal, Veillonella parvula, failed to upregulate these same MMPs. Dentilisin-induced upregulation of MMPs was mediated via TLR2 and MyD88 activation, since knockdown of expression of either abrogated these effects. Challenge with purified dentilisin upregulated the same MMPs while a dentilisin-deficient T. denticola mutant had no effect. Finally, T. denticola-mediated activation of TLR2/MyD88 lead to the nuclear translocation of the transcription factor Sp1, which was shown to be a critical regulator of all T. denticola-dependent MMP expression. Taken together, these data suggest that T. denticola dentilisin stimulates tissue-destructive cellular processes in a TLR2/MyD88/Sp1-dependent fashion.

Detection of oral bacteria on the tongue dorsum using PCR amplification of 16S ribosomal RNA and its association with systemic disease in middle-aged and elderly patients

The association between oral health and systemic disease is recognized in the literature. The present study aimed to clarify the association between oral bacteria on the tongue dorsum and factors associated with oral health and systemic disease in middle-aged and elderly patients. The association between bacterial numbers, oral health status and systemic disease was preliminarily investigated in 70 patients (mean age, 69.5 years; range, 45-92 years) who visited the Department of Oral Health, Hiroshima University Hospital (Hiroshima, Japan). The bacterial 16S ribosomal RNA gene was employed to quantitate bacterial numbers using real-time polymerase chain reaction (PCR). PCR was also performed to detect the DNA of periodontal disease-related bacteria. Oral bacterial numbers were marginally negatively correlated with moisture levels on the tongue surface [Spearman's rank correlation coefficient (R)=-0.131, P=0.28). Subjects with bleeding on probing (BOP) or a ≥4 mm probing depth (PD) exhibited higher Porphyromonas gingivalis (P. gingivalis)-positive rates (50.0 and 51.1%, respectively) than those without BOP or a <4 mm PD (39.5 and 30.4%, respectively). Subjects with medical histories of hypertension, diabetes, stroke and heart disease exhibited a trend toward higher P. gingivalis-positive rates than those without such disorders. These findings indicated that the tongue moisture level may be associated with bacterial numbers on the tongue surface, while P. gingivalis on the tongue surface may be associated with systemic and periodontal diseases. Further investigation in a larger number of participants is necessary to clarify the correlation between bacterial numbers and systemic disease.

Immunological and microbiological periodontal profiles in isolated growth hormone deficiency

BACKGROUND

Growth hormone (GH) has been identified as an important regulator of the immune response. We have previously shown that adults with isolated GH deficiency (IGHD) due to a mutation in the GH releasing hormone receptor (GHRHR) gene, have a greater chance of having periodontitis. However, the interaction of GH with periodontal tissues is still unknown, and this population has emerged as a unique model to investigate this issue. Therefore, we evaluated the microbiological and immunological periodontal profiles of such individuals.

METHODS

Nineteen IGHD and 19 controls matched by age, sex, diabetes, and smoking status, were enrolled in this case-control study. Periodontal clinical parameters (probing depth [PD] and clinical attachment loss [AL]) were measured at six sites per tooth. Immune mediators (C-reactive protein, matrix metalloproteinase [MMP]-8, MMP-9, interleukin [IL]-1α, IL-6, IL-8, tumor necrosis factor [TNF]-α, adiponectin, and leptin) were analyzed by enzyme-linked immunosorbent assay (ELISA) in the gingival crevicular fluid (GCF) in four non-adjacent sites for each participant (two with PD ≤3 mm [shallow sites] and two with PD ≥7 mm or the worst PD found in the mouth [deep sites]). Bacterial quantification (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia) of subgingival biofilm samples collected from these same sites was performed by quantitative real-time polymerase chain reaction (qPCR).

RESULTS

IGHD individuals presented higher values of PD and AL, and increased levels of CRP, IL-8, MMP-8, and adiponectin in the GCF. Bacterial quantification did not identify differences between the two groups.

CONCLUSION

IGHD alters the local immune response in periodontal pockets leading to greater attachment loss, and GH stands out as an important hormone to be evaluated in the pathogenesis of periodontitis.

Amixicile, a novel strategy for targeting oral anaerobic pathogens

The oral microflora is composed of both health-promoting as well as disease-initiating bacteria. Many of the disease-initiating bacteria are anaerobic and include organisms such as Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, and Tannerella forsythia. Here we investigated a novel therapeutic, amixicile, that targets pyruvate:ferredoxin oxidoreductase (PFOR), a major metabolic enzyme involved in energy generation through oxidative decarboxylation of pyruvate. PFOR is present in these anaerobic pathogenic bacteria and thus we hypothesized that amixicile would effectively inhibit their growth. In general, PFOR is present in all obligate anaerobic bacteria, while oral commensal aerobes, including aerotolerant ones, such as Streptococcus gordonii, use pyruvate dehydrogenase to decarboxylate pyruvate. Accordingly, we observed that growth of the PFOR-containing anaerobic periodontal pathogens, grown in both monospecies as well as multispecies broth cultures was inhibited in a dose-dependent manner while that of S. gordonii was unaffected. Furthermore, we also show that amixicile is effective against these pathogens grown as monospecies and multispecies biofilms. Finally, amixicile is the first selective therapeutic agent active against bacteria internalized by host cells. Together, the results show that amixicile is an effective inhibitor of oral anaerobic bacteria and as such, is a good candidate for treatment of periodontal diseases.

Simple platelet markers: Mean platelet volume and congestive heart failure coexistent with periodontal disease. Pilot studies

BACKGROUND

Conducted pilot study concerning mean platelet volume (MPV) parameter among patients suffering from congestive heart failure and periodontal disease.

METHODS

Examination of dynamic changes of platelet and periodontal markers in group of 50 patients before and an average of 6 months subsequent to professional periodontal treatment.

RESULTS

Both platelet and periodontal parameters decreased after periodontal treatment, what is more, the decrease of MPV value due to periodontal disease/mm improvement was shown to be statistically significant (p = 0.05).

CONCLUSIONS

Improvement of periodontal status may influence decrease of MPV value and increase of congestive heart failure treatment efficacy and effect patient comfort. It is a new, not frequently used pattern of chronic disease treatment optimalization.

Nonsurgical therapy of chronic periodontitis with adjunctive systemic azithromycin or amoxicillin/metronidazole

OBJECTIVES

The objective of the present study is to compare the effect of systemic adjunctive use of azithromycin with amoxicillin/metronidazole to scaling and root planing (SRP) in a clinical study.

MATERIALS AND METHODS

Data from 60 individuals with chronic periodontitis were evaluated after full-mouth SRP. Antibiotics were given from the first day of SRP, in the test group (n = 29), azithromycin for 3 days and, in the control group (n = 31), amoxicillin/metronidazole for7 days. Probing depth (PD), attachment level (AL), and bleeding on probing (BOP) were recorded at baseline and after 3 and 12 months. Gingival crevicular fluid was analyzed for matrix metalloprotease (MMP)-8 and interleukin (IL)-1beta levels. Subgingival plaque was taken for assessment of the major bacteria associated with periodontitis.

RESULTS

In both groups, PD, AL, and BOP were significantly reduced (p < 0.001). A few significant differences between the groups were found; AL and BOP were significantly better in the test than in the control group at the end of the study (p = 0.020 and 0.009). Periodontopathogens were reduced most in the test group.

CONCLUSIONS

A noninferiority of the treatment with azithromycin in comparison with amoxicillin/metronidazole can be stated. The administration of azithromycin could be an alternative to the use of amoxicillin/metronidazole adjunctive to SRP in patients with moderate or severe chronic periodontitis; however, a randomized placebo-controlled multicenter study is needed.

CLINICAL RELEVANCE

Application of azithromycin as a single antibiotic for 3 days might be considered as an additional adjunctive antibiotic to SRP in selected patients.

Association between Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis in subgingival plaque and clinical parameters, in Argentine patients with aggressive periodontitis

BACKGROUND

Aggregatibacter actinomycetemcomitans (Aa) and Porphyromonas gingivalis (Pg) have been associated with aggressive (AgP) and chronic periodontitis.

OBJECTIVE

The aim of this study was to evaluate the levels of Aa and Pg in gingival crevicular fluid (GCF) of patients with AgP and its relation with clinical parameters.

DESIGN

Sixteen females and fourteen males with clinical diagnosis of AgP aged 17-23 years and their match's controls, were included in this study. Clinical recording concerning probing pocket depth, clinical attachment level, plaque index and gingival bleeding index were performed at baseline, 30 and 60 days after baseline. After clinical examination GCF samples were analyzed for Aa and Pg with a real-time polymerase chain reaction technique. Patients group was treated with a combined of mechanical and oral antibiotic therapy (doxycycline 100 mg/day, during 21 days). A multivariate analysis was used to determine the relationship between Aa and Pg counts with clinical parameters.

RESULTS

GCF from all subjects was positive for Aa and PG. In controls Pg concentration was higher than Aa (Pg: 42,420 ± 3,034 copies/ml; Aa: 66.6 ± 5.4 copies/ml p < 0.001) while in patients both microbes showed the same concentration (Aa: 559,878 ± 39,698 Pg: 572,321 ± 58,752). A significant and positive correlation was observed between counts of Aa and Pg (R square: 0.7965, p < 0.0001). Female showed more counts/ml. Aa might be closely associated with clinical parameters while Pg did not. At 30 and 60 days Aa counts in patients were similar to controls while Pg counts were equal to baseline. However, in spite of Pg presence a clinical improvement was observed in all patients.

CONCLUSIONS

In our population the presence of Aa may be associated with AgP while Pg may be in GCF as an opportunistic pathogen which might caused disease when the ecological balance was favorable.