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

A View on Polymerase Chain Reaction as an Outstanding Molecular Diagnostic Technique in Periodontology

Objectives

This study presents a discussion on the fundamentals of polymerase chain reaction (PCR) and its use as a diagnostic tool in periodontology.

Materials and Methods

A computer-aided as well as hand-made search in PubMed and Scopus indexed journals (relevant to the topic) was done by keywords of molecular technique in periodontology, PCR, applications of PCR, and PCR in periodontics. Only the papers in the English language and outlining PCR and its association with periodontology were collected and utilized to provide a succinct review. There was no limitation for publication time.

Results

The results of our search showed that PCR has turned into a standard in diagnosis in the field of periodontology. A variety of researches has demonstrated that its sensitive, and specific characteristics make it a quick and effective technique of recognition, identification, and quantification of microorganisms. Identification of various immunoinflammatory markers at the mRNA expression level as well as ascertaining gene-related polymorphisms can also be performed.

Conclusions

The mechanisms of periodontal disease can further become clarified using PCR. Clinical Relevance. PCR as a diagnostic method can play a main part in the validation of the clinical diagnosis of periodontal disease indicating the reason, pathogenesis, clinical steps, progress, and prognosis of the disease.

Porphyromonas gingivalis: where do we stand in our battle against this oral pathogen?

Periodontal diseases, such as gingivitis and periodontitis, are inflammatory diseases triggered by pathogenic bacteria that lead to damage of the soft tissue and bone supporting the teeth. Amongst the identified oral periodontopathogenic bacteria, Porphyromonas gingivalis is able to enhance oral dysbiosis, which is an imbalance in the beneficial commensal and periodontal pathogenic bacteria that induces chronic inflammation. Given the critical role of oral pathogenic bacteria like P. gingivalis in the pathogenesis of periodontitis, local and/or systemic antibacterial therapy has been suggested to treat this disease, especially in its severe or refractory forms. Nevertheless, the majority of the antibacterial agents currently used for the treatment of periodontal diseases are broad-spectrum, which harms beneficial bacterial species that are critical in health, inhibit the growth of pathogenic bacteria, contribute in protecting the periodontal tissues to damage and aid in its healing. Thus, the development of more effective and specific antibacterial agents is needed to control oral pathogens in a polymicrobial environment. The strategies for the development of novel antibacterial agents include natural product isolation as well as synthetic and semi-synthetic methodologies. This review presents an overview of the periodontal diseases gingivitis and periodontitis along with current antibacterial treatment options (i.e., classes of antibacterial agents and the mechanism(s) of resistance that hinder their usage) used in periodontal diseases that specifically target oral pathogens such as P. gingivalis. In addition, to help medicinal chemists gain a better understanding of potentially promising scaffolds, this review provides an in-depth coverage of the various families of small molecules that have been investigated as potential anti-P. gingivalis agents, including novel families of compounds, repositioned drugs, as well as natural products.

Weissella cibaria CMU exerts an anti‑inflammatory effect by inhibiting Aggregatibacter actinomycetemcomitans‑induced NF‑κB activation in macrophages

Periodontitis is a chronic inflammatory disease caused by various periodontal pathogens. Weissella cibaria CMU (oraCMU) is a probiotic that promotes oral health. However, its anti‑inflammatory effects against periodontal pathogens have not yet been investigated. The present study evaluated the anti‑inflammatory effects of live oraCMU against stimulation with the formalin‑inactivated periodontal pathogen Aggregatibacter actinomycetemcomitans in RAW 264.7 macrophages. Cell viability was analyzed by the MTS assay in a dose‑dependent manner (at multiplicities of infection of 0.1, 1, 10, 100 and 1,000). Nitric oxide (NO) was monitored using the Griess test. The mRNA expression of proinflammatory cytokines such as interleukin (IL)1β and IL6 was assessed by reverse transcription‑quantitative PCR. Western blotting was used to examine the effects of oraCMU on the phosphorylation of NF‑κB inhibitor α (IκBα) and IκBα kinase (IKK), the nuclear translocation of the NF‑κB subunit p65 and the expression of inducible NO synthase (iNOS). Live oraCMU had no cytotoxic effects on RAW 264.7 macrophages. In A. actinomycetemcomitans‑stimulated RAW 264.7 macrophages, oraCMU reduced NO production by suppressing iNOS expression and downregulating the mRNA expression of proinflammatory cytokines in a dose‑dependent manner. IKK phosphorylation and IκBα degradation were dose‑dependently inhibited by oraCMU and the nuclear translocation of p65 via the canonical NF‑κB pathway was simultaneously reduced. The results indicated that oraCMU possessed anti‑inflammatory activity associated with the inhibition of NF‑κB signal activation in response to periodontal pathogens. This suggests that oraCMU is a beneficial anti‑inflammatory probiotic that can aid in the maintenance of oral health.

The role of Toll-like receptors in periodontitis

Periodontitis is a common infectious disease. Recent studies have indicated that the progression of periodontitis may be regulated by interactions between host immunity and periodontopathic bacteria. Although periodontopathic bacteria can destroy periodontal tissue, a dysfunctional host immune response triggered by the bacteria can lead to more severe and persistent destruction. Toll-like receptors (TLRs), a type of pattern recognition receptor (PRR) that recognizes pathogens, have been implicated in host innate immune responses to periodontopathic bacteria and in the activation of adaptive immunity. TLR-targeted drugs may hold promise to treat periodontal disease. This review summarizes recent studies on the role of TLRs in periodontitis and discusses areas needing further research. We believe TLRs may be an effective biomarker for the prevention, diagnosis, and treatment of periodontitis in the near future.

Polymerase chain reaction: A molecular diagnostic tool in periodontology

This review discusses the principles of polymerase chain reaction (PCR) and its application as a diagnostic tool in periodontology. The relevant MEDLINE and PubMed indexed journals were searched manually and electronically by typing PCR, applications of PCR, PCR in periodontics, polymorphism studies in periodontitis, and molecular techniques in periodontology. The searches were limited to articles in English language and the articles describing PCR process and its relation to periodontology were collected and used to prepare a concise review. PCR has now become a standard diagnostic and research tool in periodontology. Various studies reveal that its sensitivity and specificity allow it as a rapid, efficient method of detecting, identifying, and quantifying organism. Different immune and inflammatory markers can be identified at the mRNA expression level, and also the determination of genetic polymorphisms, thus providing the deeper insight into the mechanisms underlying the periodontal disease.

Clinical Therapeutic Effects of the Application of Doxycycline in the Treatment of Periodontal Disease

OBJECTIVE

To compare the therapeutic effects of the application of doxycycline-full dose (100 mg) and sub-dose (20 mg) in the treatment of periodontal disease.

MATERIAL AND METHODS

A total of 60 patients with periodontal disease were examined. Patients are divided into two groups: A) treated with antimicrobial dose of 100 mg doxycycline once daily for 30 days, and B) treated with 2 x 20 mg/day. doxycycline, during 75 days. Among all patients a conservative treatment was carried out and ordinated the proper dose doxycycline in total dose during treatment from 3 gr. Index of dental plaque by Löe-Sillness, index of gingival inflammation and gingival bleeding by Cowell were followed.

RESULTS

Values of dental plaque in relation first examination, 10th, 20th day, 1 month and 2.5 months, showed that after 2.5 months, average value (x = 0.83) of dental plaque in second group is slightly less than the value (x = 0.93) of dental plaque in the first group. The average value (x = 0.17) of gingival inflammation in second group is significantly less than the value (x = 0.50) of gingival inflammation in the first group. The average value (x = 0.97) of gingival bleeding in patients from the first group was significantly higher than value(x = 0.37) of gingival bleeding in the second group.

CONCLUSION

Patients whose therapy was helped by a sub-dose doxycycline demonstrated positive therapeutic effects on gingival inflammation and bleeding.