The microbial challenge in periodontitis

Effects of periodontal treatment on periodontal status in Finland: a register-based study

OBJECTIVE

This register-based follow-up study investigated periodontal status after periodontal treatment (PT) based on need following oral health examination (OHE).

MATERIALS AND METHODS

A total of 42,533 adults aged 18-89 years receiving OHE in the public oral health clinics of the City of Helsinki in 2009 were included. Dentists recorded periodontal status by the Community Periodontal Index (CPI), and determined the individual recall interval (IRI). Follow-up OHE between 2010 and 2015 was performed for 16,040 adults based on IRI or later. Outcome of interest was change of CPI during follow-up and was modelled with proportional odds model for each sextant separately. Results were reported as odds ratios (ORs).

RESULTS

Signs of periodontal disease were present in 95% of the study population. Symptoms of periodontitis (CPI score 3 or 4) were observed in 24% of patients. In models, PT indicated better outcome in all six sextants and in sextant 5 after one treatment (OR 5.05, 95% confidence interval [CI] 4.53-5.63). A poorer outcome was observed in patients with diabetes or severe mental disorders and in men.

CONCLUSIONS

The study population had a high prevalence of periodontal diseases. Men and patients with diabetes or severe mental disorders should be specifically targeted by dentists.

Biomechanical and Biological Multidisciplinary Strategies in the Orthodontic Treatment of Patients with Periodontal Diseases: A Review of the Literature

Orthodontic treatment aims to correct malocclusions and ensure the overall health and stability of the periodontium. The relationship between orthodontic therapy and periodontal health is intricate and multifaceted, and a comprehensive approach is often required to achieve optimal outcomes. Firstly, this article delves into the impact of orthodontic mechanics on periodontal tissues, emphasizing the importance of minimizing iatrogenic effects such as root resorption and gingival recession. Understanding the biomechanical principles allows for the development of treatment plans that mitigate these risks while achieving the desired tooth movement. Effective communication and coordinated treatment protocols are essential for managing periodontal issues before, during, and after orthodontic intervention. To optimize outcomes, periodontal considerations such as gingival biotype, attachment levels, and bone support must be integrated into treatment planning. Additionally, adjunctive periodontal therapies such as selective alveolar decortication and regenerative procedures are explored as valuable tools to enhance periodontal support and optimize treatment outcomes. This narrative review explores strategies to attain periodontal goals in orthodontic patients, thereby facilitating successful treatment. Furthermore, the review examines the role of interdisciplinary collaborations between orthodontists and periodontists. In conclusion, achieving periodontal goals in orthodontic patients requires a comprehensive approach that addresses biomechanical principles, interdisciplinary collaboration, patient education, and adjunctive periodontal therapies. By integrating periodontal considerations into orthodontic treatment planning and execution, clinicians can ensure straight teeth and a healthy and stable periodontium, ultimately leading to successful treatment outcomes and long-term oral health.

The Evaluation of a 5-miRNA Panel in Patients with Periodontitis Disease

INTRODUCTION

Side by side with tooth decay, periodontitis remains one of the most common oral diseases and is increasingly recognized as a serious public health concern worldwide.

OBJECTIVES

The present study aims at comparing the levels of 5 specific miRNAs (miR-29b-3p, miR-34a-5p, miR-155-5p, miR-181a-5p, and miR-192-5p) in patients with periodontal disease and healthy controls.

METHODS

The pathogenic mechanism is related to the activation of immune response and significant alteration of coding and noncoding genes, including miRNA. The study includes 50 subjects (17 with periodontal disease and 33 healthy controls) with a mean age of 45.3 y. In both periodontitis patients and healthy controls, a panel of 5 miRNAs (miR-29b-3p, miR-34a-5p, miR-155-5p, miR-181a-5p, and miR-192-5p) is examined by determining their expression levels with quantitative reverse transcription polymerase chain reaction.

RESULTS

The periodontitis patients express high levels of all the investigated miRNAs. Receiver operating characteristic curve analysis shows an area under the curve (AUC) of 0.69 to 0.74 for individual transcripts with the highest AUC value observed for miR-192, followed by miR-181a.

CONCLUSIONS

The study indicates that the 5-miRNA panel can be used as biomarker for periodontitis. In this way, all implantology procedures and treatment options for patients diagnosed with periodontitis can be improved for better long-term results, predictability, and follow-up frequency.

KNOWLEDGE TRANSFER STATEMENT

The discovery of a miRNA panel as a potential biomarker for periodontitis offers major opportunities for practical application. Our study can improve diagnostic accuracy; researchers can develop new theories on molecular mechanisms and biomarker discovery.

Influence of METTL3 knockdown on PDLSC osteogenesis in E. coli LPS-induced inflammation

OBJECTIVE

This study aimed to investigate the effect of METTL3 knockdown on osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) in the weak inflammation microenvironments, as well as the underlying mechanisms.

MATERIALS AND METHODS

PDLSCs were stimulated by lipopolysaccharide from Escherichia coli (E. coli LPS), followed by quantification of METTL3. METTL3 expression was assessed using RT-qPCR and Western blot analysis in periodontitis. METTL3 knockdown PDLSCs were stimulated with or without E. coli LPS. The evaluation included proinflammatory cytokines, osteogenic markers, ALP activity, and mineralized nodules. Bioinformatics analysis and Western blot determined the association between METTL3 and the PI3K/Akt pathway.

RESULTS

METTL3 was overexpressed in periodontitis. METTL3 knockdown in PDLSCs reduced proinflammatory cytokines, osteogenic markers, ALP activity, and mineralized nodules in both environments. Bioinformatics analysis suggested a link between METTL3 and the PI3K/Akt pathway. METTL3 knockdown inhibited PI3K/Akt signaling pathway activation.

CONCLUSION

METTL3 knockdown might inhibit osteogenesis in PDLSCs through the inactivation of PI3K/Akt signaling pathway. Concomitant findings might shed novel light on the roles and potential mechanisms of METTL3 in the LPS-stimulated inflammatory microenvironments of PDLSCs.

The Anti-Inflammatory Effect of SDF-1 Derived Peptide on Porphyromonas gingivalis Infection via Regulation of NLRP3 and AIM2 Inflammasome

(1) Background: Peptides are appealing as pharmacological materials because they are easily produced, safe, and tolerable. Despite increasing gum-care awareness, periodontitis is still prevalent and is influenced by factors like high sugar consumption, smoking, and aging. Porphyromonas gingivalis is considered a major etiologic agent of periodontitis and activates the NLR family pyrin domain containing 3 (NLRP3) but is absent in melanoma 2 (AIM2) inflammasomes, resulting in pro-inflammatory cytokine release. (2) Methods: We examined the anti-inflammatory effects of 18 peptides derived from human stromal cell-derived factor-1 (SDF-1) on THP-1 macrophages. Inflammation was induced by P. gingivalis, and the anti-inflammatory effects were analyzed using molecular biological techniques. In a mouse periodontitis model, alveolar bone resorption was assessed using micro-CT. (3) Results: Of the 18 SDF-1-derived peptides, S10 notably reduced IL-1β and TNF-α secretion. S10 also diminished the P. gingivalis-induced expression of NLRP3, AIM2, ASC (apoptosis-associated speck-like protein), caspase-1, and IL-1β. Furthermore, S10 attenuated the enhanced TLR (toll-like receptor) signaling pathway and decreased the phosphorylation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs). In addition, S10 mitigated alveolar bone loss in our P. gingivalis-induced mouse model of periodontitis. (4) Conclusions: S10 suppressed TLR/NF-κB/NLRP3 inflammasome signaling and the AIM2 inflammasome in our P. gingivalis-induced murine periodontitis model, which suggests that it has potential use as a therapeutic treatment for periodontitis.

Laser Therapy Versus Traditional Scaling and Root Planing: A Comparative Review

Scaling and root planing (SRP) removes bacterial plaque, calculus, and associated microorganisms from the surface of the tooth and the surrounding soft tissue. While complete eradication of pathogenic microbes is impossible, gross removal can lower the microbial load, which in turn reduces inflammation and contributes to positive clinical outcomes. Instrumentation in limited-access anatomic areas like furcation, grooves, deep pockets, concavities, and distal molar areas is technically demanding with traditional mechanical debridement. However, emerging advanced systems such as lasers with bactericidal and detoxification effects offer the benefit of reaching limited-access areas that traditional SRP cannot reach. A digitized search was done on PubMed, Embase, Medline, and Google Scholar using the keywords "lasers", "periodontal therapy", "scaling", and "root planing". Upon screening and reviewing, the shortlisted articles comprised narrative reviews, systematic reviews, randomized controlled trials, comparative studies, split-mouth studies, case series, and reports of non-surgical laser therapy and lasers as an adjunct to SRP. This review presents a comprehensive comparative evaluation of different laser modalities utilized in non-surgical periodontal treatment in contrast to standard SRP, rather than an exhaustive article review. It delves into the history and development of lasers, highlighting key advancements made in the realm of periodontics and dental care. This review includes an elucidation of the theory behind laser operation, along with an exploration of its intrinsic characteristics and breakdown of the various types of lasers that are currently available, and an examination of existing literature in both present and historical contexts regarding the comparison of various types of lasers with traditional periodontal treatment.

Antibacterial activities of phytochemicals against Porphyromonas gingivalis with and without experimental fluoride varnish for periodontal disease prevention

We aimed to evaluate the antibacterial activity of phytochemicals with or without an experimental fluoride varnish against Porphyromonas gingivalis. Five phytochemicals, chrysophanol (CHR), emodin (EMO), anthrarufin (ANT), bavachalcone (BCC), and isobavachromene (IBC), were tested using agar diffusion, minimal inhibition concentration (MIC), and minimum bacterial concentration (MBC) assays. We also assessed the cell viability and cytotoxicity of phytochemicals. All phytochemicals showed clear inhibition zones in the agar diffusion test. The inhibition zones of all phytochemical-containing fluoride varnishes were similar to or larger than that of the positive control, excluding that of 1 mM EMO. With or without the fluoride varnish, BCC exhibited the lowest MIC and MBC levels. Cell viability was high in the presence of all phytochemicals except 200 μM EMO. In conclusion, BCC was most effective as a phytochemical alone, while all phytochemical-containing fluoride varnishes inhibited P. gingivalis growth without cytotoxicity.

Assessment of IL-8 Levels in Saliva of Healthy and Chronic Periodontitis Individuals

Inflammation of the gums and other tissues supporting the teeth, as well as gradual loss of attachment and bone, are the results of chronic periodontitis, an infectious illness. During inflammation, a group of low molecular weight proteins called cytokines facilitate a complex interaction between inflammatory cells (such neutrophils) and other cellular components in connective tissue. The cytokine interleukin-8 (IL-8) is a potent neutrophil chemoattractant. Therefore, it is possible that IL-8 is crucial to the development of periodontitis's pathology.

Objectives

1) To estimate concentration of IL-8 levels in healthy individuals and chronic periodontitis individuals. 2) To compare IL-8 levels in healthy and chronic periodontitis individuals.

Materials and Methods

Participants in this research will be recruited from among those who visit the outpatient department (OPD) at the NGH Institute of Dental Sciences and Research Centre, Belagavi, run by the Maratha Mandal.

Control Group

Subjects with no clinical attachment loss (CAL) and a probing depth of 3.0 mm are considered to be periodontally healthy. Those in Group 2 (chronic periodontitis) have a chronic form of the disease, as shown by a probing pocket depth (PPD) of less than 5 mm and CAL of less than 2 mm. Unstimulated saliva sample will be collected in a 5 mL wide-mouthed sterile container by spitting method. Samples collected will be centrifuged. The supernatant is collected and stored at -80°C and then assayed for IL-8 concentration by using the standardized IL-8 ELISA kit.

Effect of 15 days -6° head-down bed rest on microbial communities of supragingival plaque in young men

Introduction

The microgravity environment astronauts experience during spaceflight can lead to an increased risk of oral diseases and possible changes in oral microecology. In this study, we aimed to assess changes in the microbial community of supragingival plaques to explore the effects of spaceflight microgravity environment on oral microecology.

Methods

Sixteen healthy male volunteers were recruited, and supragingival plaque samples were collected under -6° head-down bed rest (HDBR) at five-time points: day 1 before HDBR; days 5, 10, and 15 of HDBR; and day 6 of recovery. Bacterial genomic DNA was sequenced using gene sequencing technology with 16S ribosomal ribonucleic acid V3-V4 hypervariable region amplification and the obtained data were analyzed bioinformatically.

Results

Alpha diversity analysis showed a significant increase in species richness in supragingival plaque samples on day 15 of HDBR compared with that at pre-HDBR. Beta diversity analysis revealed that the community composition differed among the groups. Species distribution showed that, compared with those at pre-HDBR, the relative abundances of Corynebacterium and Aggregatibacter increased significantly during HDBR, while those of Veillonella, Streptococcus, and Lautropia decreased significantly. Moreover, compared with those at pre-HDBR, the relative abundance of Leptotrichia increased significantly on day 6 of recovery, whereas the relative abundances of Porphyromonas and Streptococcus decreased significantly. Network analysis showed that the interaction relationship between the dominant genera became simpler during HDBR, and the positive and negative correlations between them showed dynamic changes. Phylogenetic investigation of communities by reconstruction of unobserved states analysis showed that the amino acid metabolism function of plaque microorganisms was more enriched during HDBR.

Discussion

In summary, in a 15-day simulated microgravity environment, the diversity, species distribution, interaction relationship, and metabolic function of the supragingival plaque microbial community changed, which suggests that microgravity may affect the oral microecosystem by changing the balance of supragingival plaque microbial communities and further leading to the occurrence and development of oral diseases.

The effect of non-surgical periodontal therapy on salivary IL-6 levels in patients with moderate to severe generalized chronic periodontitis

BACKGROUND

Gene regulation of IL-6 is characterized by the presence of inflammatory cytokines, bacterial products, viral infection, and activation of the diacylglycerol-, cyclic AMP-, or Ca + + -activated signal transduction pathways.

AIM

Scaling and root planning (SRP), a non-surgical periodontal therapy, was studied in connection to several clinical parameters for its effect on salivary IL-6 levels in patients with generalized chronic periodontitis.

METHODS

For this study, a total of 60 GCP patients were included. Plaque index (PI), gingival index (GI), pocket probing depth (PPD), bleeding on probing percentage (BOP%), and clinical attachment loss were among the clinical indicators covered (CAL).

RESULTS

Following SRP, mean IL-6 levels in patients with GCP were significantly higher in the pre-treatment group (2.93 5.17 pg/ml; p 0.05) than in the posttreatment group (5.78 8.26 pg/ml; baseline). Pre- and post-treatment IL-6 levels for PI (pre), BOP percent (pre/post), GI (post), and PPD were found to be positively correlated (post). In patients with GCP, the study showed a statistically significant correlation between periodontal metrics and salivary IL-6.

CONCLUSIONS

Changes in periodontal indices and IL-6 levels that are statistically significant over time indicate that non-surgical treatment is effective, and IL-6 can be regarded as a potent disease activity marker.

Mouthwash Effects on the Oral Microbiome: Are They Good, Bad, or Balanced?

This narrative review describes the oral microbiome, and its role in oral health and disease, before considering the impact of commonly used over-the-counter (OTC) mouthwashes on oral bacteria, viruses, bacteriophages, and fungi that make up these microbial communities in different niches of the mouth. Whilst certain mouthwashes have proven antimicrobial actions and clinical effectiveness supported by robust evidence, this review reports more recent metagenomics evidence, suggesting that mouthwashes such as chlorhexidine may cause "dysbiosis," whereby certain species of bacteria are killed, leaving others, sometimes unwanted, to predominate. There is little known about the effects of mouthwashes on fungi and viruses in the context of the oral microbiome (virome) in vivo, despite evidence that they "kill" certain viral pathogens ex vivo. Evidence for mouthwashes, much like antibiotics, is also emerging with regards to antimicrobial resistance, and this should further be considered in the context of their widespread use by clinicians and patients. Therefore, considering the potential of currently available OTC mouthwashes to alter the oral microbiome, this article finally proposes that the ideal mouthwash, whilst combatting oral disease, should "balance" antimicrobial communities, especially those associated with health. Which antimicrobial mouthwash best fits this ideal remains uncertain.

Localized microbially induced inflammation influences distant healthy tissues in the human oral cavity

Variation in human immune response to the same bacterial or viral pathogen is well established in the literature. Variation in immune response to microbial challenge has also been observed within the human oral cavity. Our recent study focused on characterizing observed variations in microbially induced gingival inflammation-resulting in three distinct clinical Inflammatory Responder Types (IRTs): High-IRT, Low-IRT, and Slow-IRT. Here, we applied a high-resolution temporal multiomic analysis during microbially induced inflammation in order to characterize the effects of localized oral inflammation on distant healthy tissues in young healthy adults. Our results highlight a nonlocalized subclinical effect with alterations in proinflammatory host mediators and an ecological shift toward dysbiosis within the subgingival microbiome in an IRT-dependent manner-despite maintained oral hygiene. Our results provide mechanistic insight into how healthy tissues within humans are influenced by distant localized inflammation and may ultimately become susceptible to disease.

Latest Concepts in Endodontic Management of Pregnant Patients

Pregnant patients and how to manage their treatments is one of the most important challenges in endodontic practice. Endodontic treatment on pregnant women is sometimes an emergency condition to control toothache due to irreversible pulpitis and odontogenic infection. Tooth decay, oral health, local and general anesthesia, analgesics, antibiotic prescription, drug interactions, and X-ray radiation are the most important considerations that may impact treatment planning and endodontic practice in pregnancy. The aim of this article is to notify and explain the latest concepts in the endodontic management of pregnant patients.

The Roles of Periodontal Bacteria in Atherosclerosis

Atherosclerosis (AS) is an inflammatory vascular disease that constitutes a major underlying cause of cardiovascular diseases (CVD) and stroke. Infection is a contributing risk factor for AS. Epidemiological evidence has implicated individuals afflicted by periodontitis displaying an increased susceptibility to AS and CVD. This review concisely outlines several prevalent periodontal pathogens identified within atherosclerotic plaques, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum. We review the existing epidemiological evidence elucidating the association between these pathogens and AS-related diseases, and the diverse mechanisms for which these pathogens may engage in AS, such as endothelial barrier disruption, immune system activation, facilitation of monocyte adhesion and aggregation, and promotion of foam cell formation, all of which contribute to the progression and destabilization of atherosclerotic plaques. Notably, the intricate interplay among bacteria underscores the complex impact of periodontitis on AS. In conclusion, advancing our understanding of the relationship between periodontal pathogens and AS will undoubtedly offer invaluable insights and potential therapeutic avenues for the prevention and management of AS.

Induction of Periodontitis Using Bacterial Strains Isolated from the Human Oral Microbiome in an Experimental Rat Model

Periodontal disease is that condition resulting in the destruction of periodontal tissues, bone resorption, and tooth loss, the etiology of which is linked to immunological and microbiological factors. The aim of this study was to evaluate the potential trigger of periodontal disease in a rat model using bacterial species incriminated in the pathology of human periodontitis and to establish their optimal concentrations capable of reproducing the disease, with the idea of subsequently developing innovative treatments for the condition. In this study, we included 15 male Wistar rats, aged 20 weeks, which we divided into three groups. In each group, we applied ligatures with gingival retraction wire on the maxillary incisors. The ligature and the gingival sac were contaminated by oral gavage with a mixture of fresh cultures of Aggregatibacter actinomycetemcomitans (A.a), Fusobacterium nucleatum (F.n) and Streptococcus oralis (S.o) in concentrations of 108, 109, and 1010 CFU/mL each for 5 days a week for 4 weeks. During the clinical monitoring period of 28 days, overlapped with the period of oral contamination, we followed the expression of clinical signs specific to periodontitis. We also monitored the evolution of body weight and took weekly samples from the oral cavity for the microbiological identification of the tested bacteria and blood samples for hematological examination. At the end of the study, the animals were euthanized, and the ligated incisors were taken for histopathological analysis. The characteristic symptomatology of periodontal disease was expressed from the first week of the study and was maintained until the end, and we were able to identify the bacteria during each examination. Hematologically, the number of neutrophils decreased dramatically (p < 0.0001) in the case of the 109 group, unlike the other groups, as did the number of lymphocytes. Histopathologically, we identified neutrophilic infiltrate in all groups, as well as the presence of coccobacilli, periodontal tissue hyperplasia, and periodontal lysis. In the 109 group, we also observed pulpal tissue with necrotic bone fragments and pyogranulomatous inflammatory reaction. By corroborating the data, we can conclude that for the development of periodontal disease using A.a, F.n, and S.o, a concentration of 109 or 1010 CFU/mL is required, which must necessarily contaminate a ligature thread applied to the level of the rat's dental pack.

Photodynamic antimicrobial therapy (AmPDT) using 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB and λ640 ± 5ηm LED light in patients undertaking orthodontic treatment

Orthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance AmPDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of AmPDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB as a photosensitizing agent combined with red LED irradiation (λ640 ± 5 ηm) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in orthodontic patients.

Effects of a 2-Year Early Childhood Vitamin D3 Intervention on Tooth Enamel and Oral Health at Age 6-7 Years

INTRODUCTION

The aim of the study was to compare the effects of a 30 µg/day versus 10 µg/day vitamin D supplementation, given during the two first years of life, on oral health at the age of six to 7 years.

METHODS

In 2013-2016, we conducted a randomized, double-blinded, clinical trial from age 2 weeks to 2 years of daily vitamin D3 supplementation (10 vs. 30 µg), including 975 healthy infants. For the present follow-up study at age 6-7 years, a sample of 123 children underwent oral examination by investigators blinded to the intervention group. Tooth enamel defect and caries findings, oral rinse active matrix metalloproteinase-8 levels, and tooth eruption were recorded. The intervention groups were compared with χ2 and Mann-Whitney U tests. Associations of the oral health outcomes were evaluated with correlation analysis and logistic regression.

RESULTS

Of the children (median age 7.4 years, 51% boys), 56% belonged to the 30 µg intervention group. Developmental defect of enamel (DDE) was found in 39% of the children in the 10 µg intervention group and in 53% of the 30 µg group (p = 0.104). In total, 94% of children were vitamin D sufficient (25[OH]D ≥50 nmol/L) and 88% had caries-free teeth. No associations were found between vitamin D intervention group in infancy and oral health or the presence of DDE.

CONCLUSION

Daily supplementation with 10 µg vitamin D3 in the Northern Hemisphere seems adequate in healthy children younger than 2 years in ensuring good oral health at early school age.

Plasma treatment effects on destruction and recovery of Porphyromonas gingivalis biofilms

The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas (NTAP) on destruction and the recovery (or re-colonization) of Porphyromonas gingivalis (P. gingivalis) in biofilms. P. gingivalis is a well-known keystone periodontal pathogen strongly associated with periodontal diseases, especially periodontitis. P. gingivalis biofilms were formed on stainless steel coupons and treated for 1, 2, and 5 minutes by NTAP of pure argon gas and argon+oxygen gas mixture. MTT assay, colony forming unit (CFU) counting assay and confocal laser scanning microscopy (CLSM) were used to assess the destruction efficiency. In addition, the plasma treated biofilms were re-cultured in the medium supplemented with antibiotics and oxidative stress sources to determine the synergy of the NTAP with other antimicrobial agents. The results showed the plasma treatment could result in 2.7 log unit reduction in bacterial load. The recovered biofilm CFU with NTAP treatment combined with sub minimal inhibition concentration of amoxicillin was 0.33 log units less than the biofilm treated with amoxicillin alone. The recovered biofilm CFU in NTAP groups was about 2.0 log units less than that in the untreated controls under H2O2 treatment. There was approximately 1.0 log unit reduction of biofilm CFU in plasma treated biofilm compared with untreated control under paraquat treatment. The plasma treated biofilms exhibited less resistance to amoxicillin and greater susceptibility to hydrogen peroxide (H2O2) and paraquat, suggesting that NTAP may enhance biofilm susceptibility to host defense. These in vitro findings suggested that NTAP could be a novel and effective treatment method of oral biofilms that cause periodontal diseases.

Host and bacterial factors linking periodontitis and rheumatoid arthritis

Observations from numerous clinical, epidemiological and serological studies link periodontitis with severity and progression of rheumatoid arthritis. The strong association is observed despite totally different aetiology of these two diseases, periodontitis being driven by dysbiotic microbial flora on the tooth surface below the gum line, while rheumatoid arthritis being the autoimmune disease powered by anti-citrullinated protein antibodies (ACPAs). Here we discuss genetic and environmental risk factors underlying development of both diseases with special emphasis on bacteria implicated in pathogenicity of periodontitis. Individual periodontal pathogens and their virulence factors are argued as potentially contributing to putative causative link between periodontal infection and initiation of a chain of events leading to breakdown of immunotolerance and development of ACPAs. In this respect peptidylarginine deiminase, an enzyme unique among prokaryotes for Porphyromonas gingivalis, is elaborated as a potential mechanistic link between this major periodontal pathogen and initiation of rheumatoid arthritis development.

Clinical Efficacy of 1% CHX Gluconate Gel and 0.12% CHX Solution: A Randomized Controlled Trial

Chlorhexidine (CHX) is an effective antibacterial agent and is used in dental treatment in several formulations. The aim of this study was to compare the effectiveness of CHX solution and CHX gel on dental plaque inhibition and gingivitis relief by a randomized clinical trial. Thirty-eight participants were randomly divided into two groups: control group (0.12% CHX solution) and test group (1% CHX gel). Participants were provided with CHX products and were instructed to use each product in the morning and evening for 1 week. Clinical results were evaluated by analyzing the collected data of Turesky et al. the modified Quigley-Hein Plaque Index (TQHPI), gingival index (GI) and the BANA test. Measurements were conducted 4 weeks and 8 weeks after using chlorhexidine products. The results were analyzed using repeated measured ANOVA and paired t-test. TQHPI and GI were significantly different after treatments in both groups (p < 0.001). The GI decreased more in the test group compared to the control group 4 weeks and 8 weeks later. In both groups, the BANA score also significantly decreased (p < 0.001) after 8 weeks, though the BANA score decreased relatively more in the CHX gel group than the CHX solution group. These results suggest that 1% CHX gel is more effective in reducing gingivitis and bacteria of periodontal disease than the 0.12% CHX solution. Therefore, the 1% CHX gel is expected to be actively used for non-surgical treatment of periodontal disease patients.

Knowledge of Physicians about the Interrelationship between Diabetes Mellitus and Periodontitis in the United Arab Emirates

OBJECTIVE

 Diabetes mellitus is a major cause of morbidity in the United Arab Emirates (UAE), highlighting a significant social and economic burden impacting the development of the country. Studies have shown a bidirectional relationship between diabetes and periodontal disease. The awareness of this relationship is imperative not only for dentists but also for the physicians who contribute toward enhancing a diabetic patient's health and lifestyle. There is a general need to highlight the importance of maintaining periodontal health and its positive effect on controlling diabetic health status. The purpose of this study is to investigate the knowledge of the physicians regarding diabetes and periodontal health.

MATERIALS AND METHODS

 A cross-sectional study involving a questionnaire was distributed to the physicians who were attending the Arab Health Conference in Dubai in 2019.

STATISTICAL ANALYSES

 A cross-tabulation analysis compared attitude, knowledge, and awareness across sector, gender, and country of graduation. A logistic regression model was used to explain the "knowledge" regarding possible confounding factors.

RESULTS

 A total of 344 physicians with an average age of 38.11 (9.31) years, comprising of 186 (53.8%) males, participated in the survey. Of those participants, 285 (82.8%) were working in the government sector health care centers versus the private health care organizations. Also, 108 (31.4%) of the participants graduated within the universities based in the UAE, while the remaining 263 (68.6%) participants graduated from medical schools from other countries. At least 265 (77%) of the participants had positive outlook toward referring patients with diabetes to their dental colleagues, while 283 (82.3%) of the physicians acknowledge that diabetes affects periodontal health. While a majority of participants 261 (76%) treat diabetic patients in their clinical practice, only 50 (19%) of the participants admit to referring these patients for a dental consultation. In addition, the survey also revealed that 225 (65.5%) physicians comprehend the bidirectional relationship of periodontal disease and diabetes.

CONCLUSION

 An appropriate dental referral protocol is recommended for all diabetic patients who visit physicians. This survey demonstrated that although the physicians present with good knowledge, they rarely refer diabetic patients to receive proper periodontal care.

Matrix metalloproteinase-9-1562 C/T promoter gene polymorphism in chronic periodontitis: A cross-sectional observational study

Background:

Matrix metalloproteinases (MMPs) are a major group of enzymes, released in inflamed periodontal tissues in large quantities, resulting in connective tissue matrix breakdown. One of the most predominant MMPs is MMP-9. Association between chronic periodontitis (CP) and MMP-9 gene polymorphism (GP) in some ethnic populations has been already established. The aim of the current study was to assess the association of single-nucleotide polymorphism in the promoter region of MMP-9 gene with CP in Kolkata population, if any.

Materials and Methods:

Forty eligible individuals were recruited for the study and grouped as A and B: Group A (twenty periodontally healthy individuals) and Group B (twenty CP patients). Venous blood samples collected from all the forty individuals were used to isolate the genomic DNA. GP for MMP-9 gene was detected using polymerase chain reaction and sequencing method. The data obtained were then analyzed statistically.

Results:

A significantly different genotypic and allelic variation was observed in the control and test groups, with C/T genotype and T allele present in only CP group.

Conclusion:

Within the limitations of this study, we can conclude that there was no significant association between patients with periodontitis and MMP-9-1562 C/T promoter GP.

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.

Dysregulation of metallothionein and zinc aggravates periodontal diseases

BACKGROUND

Periodontitis (PD) is a multifaceted inflammatory disease connected to bacterial infection that results in the destruction of tooth supporting structures and eventually tooth loss. Given their involvement in infection and inflammation, both metallothionein (MT) and zinc (Zn) might play vital roles in the development and progression of PD. More specifically, both MT and Zn are heavily involved in regulating immune functions, controlling bacterial infection, balancing inflammatory responses, and reducing oxidative stress, all of which are associated with the pathogenesis of PD.

OBJECTIVE

This review paper will explore the physiological functions of MT and Zn and hypothesise how dysregulation could negatively affect periodontal health, leading to PD.

FINDINGS

Bacterial lipopolysaccharide (LPS) derived from periodontal pathogens, namely P. gingivalis initiates the acute phase response, thus upregulating the expression of MT which leads to the subsequent deficiency of Zn, a hallmark of periodontal disease. This deficiency leads to ineffective NETosis, increases the permeability of the gingival epithelium, and disrupts the humoral immune response, collectively contributing to PD. In addition, the presence of LPS in Zn deficient conditions favours M1 macrophage polarisation and maturation of dendritic cells, and also inhibits the anti-inflammatory activity of regulatory T cells. Collectively, these observations could theoretically give rise to the chronic inflammation seen in PD.

CONCLUSION

A disrupted MT and Zn homeostasis is expected to exert an adverse impact on periodontal health and contribute to the development and progression of PD.

Human variation in gingival inflammation

Oral commensal bacteria actively participate with gingival tissue to maintain healthy neutrophil surveillance and normal tissue and bone turnover processes. Disruption of this homeostatic host-bacteria relationship occurs during experimental gingivitis studies where it has been clearly established that increases in the bacterial burden increase gingival inflammation. Here, we show that experimental gingivitis resulted in three unique clinical inflammatory phenotypes (high, low, and slow) and reveal that interleukin-1β, a reported major gingivitis-associated inflammatory mediator, was not associated with clinical gingival inflammation in the slow response group. In addition, significantly higher levels of Streptococcus spp. were also unique to this group. The low clinical response group was characterized by low concentrations of host mediators, despite similar bacterial accumulation and compositional characteristics as the high clinical response group. Neutrophil and bone activation modulators were down-regulated in all response groups, revealing novel tissue and bone protective responses during gingival inflammation. These alterations in chemokine and microbial composition responses during experimental gingivitis reveal a previously uncharacterized variation in the human host response to a disruption in gingival homeostasis. Understanding this human variation in gingival inflammation may facilitate the identification of periodontitis-susceptible individuals. Overall, this study underscores the variability in host responses in the human population arising from variations in host immune profiles (low responders) and microbial community maturation (slow responders) that may impact clinical outcomes in terms of destructive inflammation.

Clinical comparison of instrumentation systems for periodontal debridement: A randomized clinical trial

OBJECTIVE

To compare clinical efficacy, chairside time and post-treatment hypersensitivity of four instruments used for subgingival periodontal debridement.

MATERIALS & METHODS

Seventeen patients with stage II and III periodontitis were enrolled in this randomized clinical trial using a split-mouth design. Quadrants were randomly divided into four treatment groups: Group A: Gracey curettes-Hu-Friedy^® ; Group B: piezoelectric ultrasonic (Satelec^® ) with No.1S insert; Group C: diamond burs 40 µm (Intensiv Perioset^® ); and Group D: piezosurgery ultrasonic (Mectron^® ) with PP1 insert. Clinical outcomes, chairside time and hypersensitivity were assessed at 1, 2, 4 and 8 weeks after treatment. The primary outcome variable was improvement in clinical attachment level.

RESULTS

At 8 weeks post-treatment, Gracey curettes, piezoelectric ultrasonic (Satelec^® ) and piezosurgery ultrasonic (Mectron^® ) were statistically more effective than diamond burs in increasing attachment level and reducing probing pocket depth. Comparison of piezoelectric ultrasonic (Satelec^® ) and piezosurgery ultrasonic (Mectron^® ) with the other instruments showed a statistical difference (p < 0.001) in chairside time. Regarding post-treatment hypersensitivity, no statistical differences were observed in any of the groups.

CONCLUSIONS

Gracey curettes, piezoelectric ultrasonic (Satelec^® ) and piezosurgery ultrasonic (Mectron^® ) were clinically more effective than diamond burs 40 µm. The ultrasonic instruments showed a significant reduction in chairside time.

Maintaining a protective state for human periodontal tissue

Periodontitis, caused by infection with periodontal pathogens, is primarily characterized by inflammatory bone resorption and destruction of connective tissue. Simply describing periodontitis as a specific bacterial infection cannot completely explain the various periodontal tissue destruction patterns observed. Periodontal tissue damage is thought to be caused by various factors. In recent years, research goals for periodontal pathogens have shifted from searching for specific pathogens to investigating mechanisms that damage periodontal tissues. Bacteria interact directly with the host in several ways, influencing expression and activity of molecules that evade host defenses, and destroying local tissues and inhibiting their repair. The host's innate and acquired immune systems are important defense mechanisms that protect periodontal tissues from attack and invasion of periodontal pathogens, thus preventing infection. Innate and acquired immunity have evolved to confront the microbial challenge, forming a seamless defense network in periodontal tissues. In the innate immune response, host cells quickly detect, via specialized receptors, macromolecules and nucleic acids present on bacterial cell walls, and this triggers a protective, inflammatory response. The work of this subsystem of host immunity is performed mainly by phagocytes, beta-defensin, and the complement system. In addition, the first line of defense in oral innate immunity is the junctional epithelium, which acts as a physical barrier to the entry of oral bacteria and other nonself substances. In the presence of a normal flora, junctional epithelial cells differentiate actively and proliferate apically, with concomitant increase in chemotactic factor expression recruiting neutrophils. These immune cells play an important role in maintaining homeostasis and the protective state in periodontal tissue because they eliminate unwanted bacteria over time. Previous studies indicate a mechanism for attracting immune cells to periodontal tissue with the purpose of maintaining a protective state; although this mechanism can function without bacteria, it is enhanced by the normal flora. A better understanding of the relationship between the protective state and its disruption in periodontal disease could lead to the development of new treatment strategies for periodontal disease.

Clinical significance of ragA, ragB, and PG0982 genes in Porphyromonas gingivalis isolates from periodontitis patients

Consistent detection of ragA, ragB, and PG0982 in the genome of Porphyromonas gingivalis (P. gingivalis) isolates from periodontitis patients suggests that genotypes containing these genes may influence virulence and P. gingivalis-associated periodontitis progression. This study evaluated the prevalence of these genes in P. gingivalis isolates from periodontitis patients (n = 28) and in isolates from periodontally healthy P. gingivalis carriers (n = 34). The association of these genes with progression of periodontitis, in vitro cell invasiveness, and bacterial survival following periodontal therapy was also assessed. Periodontal charting and microbiological sampling were done at baseline, and at 6, 12, and 24 months following subgingival debridement of the periodontitis patients. Healthy controls were assessed at baseline for comparison. P. gingivalis isolates were analysed by ragA, ragB, and PG0982 specific polymerase chain reaction (PCR) and Sanger sequencing. Primary human gingival fibroblasts were used for invasion experiments. Results showed that 25% of the tested isolates from the periodontitis group had ragB detected, whereas this gene was undetected in isolates from healthy participants. However, none of the selected genes was associated with an increased cell invasiveness in vitro, with bacterial survival, or with significant clinical periodontal parameter changes. Identification of genes that influence P.gingivalis virulence and therapeutic outcome may have a diagnostic or prognostic value.

Putative periodontal pathogens in persisting periodontal pockets of endodontic origin

Background:

The microbial profile of endodontically treated teeth, presenting with a persisting deep periodontal pocket, secondary to a primary endodontic lesion, draining through the gingival crevice, has received very less attention. This observational study was done to evaluate if these sites with persisting pockets of endodontic origin persist because they have acquired bacteria which are considered as putative periodontal pathogens.

Materials and Methods:

Subgingival plaque samples were collected from fifty patients diagnosed with a primary endodontic and a secondary periodontal lesion that persisted even after completion of the root canal treatment. Clinical parameters such as probing pocket depth, clinical attachment level, plaque index, furcation, and tooth mobility were recorded. Real-time polymerase chain reaction was used to determine the possible association between six bacteria, which are frequently associated with periodontal and endodontic lesions.

Results:

The mean cycle threshold value for Treponema denticola (Td) was found to be 33.74, and for Enterococcus faecalis (Ef), it was 34.39. With regard to clinical attachment loss, Td (P < 0.04) and Parvimonas micra (P < 0.05) had a significant correlation.

Conclusion:

Ef (92%) and Td (86%) were found to be most prevalent. Porphyromonas gingivalis and Tannerella forsythia were in minimal to nonexistent levels.

A pilot study of red complex and three genera subgingival microbiome in periodontitis subjects with and without diabetes, evaluated by MinION platform

Background: Subgingival niche is one biofilm habitat containing rich microbiota, which plays an active role in maintaining the health of periodontal tissue and determining host response. As such, a study of changing subgingival biofilms is important for understanding the effect of a systemic condition. In this study, we compared the occurrence of six bacteria cohabiting in the subgingival area of periodontitis subjects, with (DP, n = 8) and without (NDP, n = 4) diabetes.

Methods: The six genus and species of targeted bacteria were confirmed by 16S rRNA amplicon sequencing on MinION nanopore platform. Descriptive statistic was used to describe the obtained data.

Results: We found that the six genus and species of targeted bacteria were detected but in different quantities in either group's periodontal pocket. Our data showed that Tannerella forsythia was the most abundant species in subgingival biofilms of the DP group of the red complex bacteria. In contrast, Aggregatibacter sp., which belongs to the phylum of proteobacteria, was present at a relatively lower level. In contrast, Fusobacterium sp., which belongs to orange complex bacteria, showed relative similarities in subgingival biofilms of both groups tested, while Veillonella sp., were abundant in the DP groups. 

Conclusions: Our data show that the diversity of classic periodontopathogens increased in the subgingival niche of periodontitis subjects with diabetes. It is the first study in Indonesia to apply MinION-based, full-length 16S rRNA amplicon sequencing in periodontitis patients with and without diabetes.

[A Meta-analysis of the effect of non-surgical periodontal therapy on inflammatory factors in patients with chronic kidney disease and periodontitis]

OBJECTIVE

A study was conducted to systematically evaluate the clinical efficacy of inflammatory factors in patients with chronic kidney disease and periodontitis after non-surgical periodontal therapy.

METHODS

We searched the databases of CNKI, Wanfang, CBM, PubMed, Embase, and Cochrane Library from inception to December 2019. Two reviewers independently collected all literature related to inflammatory factors in patients with chronic kidney disease and periodontitis after non-surgical periodontal therapy. These factors include C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α). The literature was screened according to the inclusion and exclusion criteria. The quality of the studies was strictly evaluated, and the data were extracted. The literature of randomized controlled trials in accordance with the standards was Meta-analyzed with Revman 5.3 software.

RESULTS

Six randomized controlled trials were included. Compared with the control groups, the results of meta-analysis showed that non-surgical periodontal therapy significantly reduced the levels of CRP [MD=-0.58, 95%CI (-1.13, -0.02), P=0.04] and IL-6 [MD=-2.76, 95%CI (-5.15, -0.37), P=0.02] in these patients but not that of TNF-α [MD=-3.87, 95%CI (-8.79, 1.05), P=0.12].

CONCLUSIONS

Simultaneous regular renal treatment and non-surgical periodontal therapy can help relieve the periodontal damage on patients with chronic kidney disease and periodontitis. Moreover, it can improve the status of some inflammatory factors. This finding is conducive to the control and treatment of chronic kidney disease and periodontitis and needs to be a focus of research and in clinical operation.

Eye on the Enigmatic Link: Dysbiotic Oral Pathogens in Ocular Diseases; The Flip Side

Mouth and associated structures were regarded as separate entities from the rest of the body. However, there is a paradigm shift in this conception and oral health is now considered as a fundamental part of overall well-being. In recent years, the subject of oral-foci of infection has attained a resurgence in terms of systemic morbidities while limited observations denote the implication of chronic oral inflammation in the pathogenesis of eye diseases. Hitherto, there is a paucity for mechanistic insights underlying the reported link between periodontal disease (PD) and ocular comorbidities. In light of prevailing scientific evidence, this review article will focus on the understudied theme, that is, the impact of oral dysbiosis in the induction and/or progression of inflammatory eye diseases like diabetic retinopathy, scleritis, uveitis, glaucoma, age-related macular degeneration (AMD). Furthermore, the plausible mechanisms by which periodontal microbiota may trigger immune dysfunction in the Oro-optic-network and promote the development of PD-associated AMD have been discussed.

Evaluation of the efficacy of a commercially available regimen vs brushing alone on established plaque and gingivitis on adolescents: Study protocol for a randomized, controlled, blind clinical trial

BACKGROUND

Dental biofilm accumulation and poor personal oral hygiene are known major risk factors for gingivitis and halitosis. However, it is not clear how studies compare the effectiveness of hygiene regimens, associated with outcomes centered on patients.

METHODS

A randomized, blind, controlled clinical trial involving 58 participants aged from 12 to 17 years, who search the Department of Pediatric Dentistry of Universidade Metropolitana de Santos, will be conducted. Immediately, the volunteers will be inserted into Group 1 (commercially available hygiene regimen) or Group 2 (tooth brushing alone). In Group 1, participants will receive Colgate Total 12 toothpastes, Plax mouthwashes and Colgate Ultrasoft toothbrushes, while Group 2 will use Colgate Cavity Protection toothpastes and Colgate Ultrasoft toothbrushes. The interventions will be conducted in the periods of 1, 3, and 6 months after the baseline, when the evaluations will also be performed. Biofilm and halitosis indexes will be evaluated. Data regarding discomfort, satisfaction and the socioeconomic/individual characteristics will also be computed.

DISCUSSION

Although toothbrushing has shown positive effects in decreasing biofilm and in gingival health, there is no comparison in the literature of different brushing regimens with halitosis measurement in adolescents. In addition, the effectiveness of these protocols would be confirmed from the acceptability of the volunteers.

Periodontal disease and cancer: Epidemiologic studies and possible mechanisms

Epidemiologic and cancer control studies on the association of periodontal disease and cancer risk mostly suggest a positive association with overall cancer risk and certain specific types of cancer. These findings are generally consistent among cross‐sectional and longitudinal studies. In this paper, we review epidemiologic studies and current knowledge on periodontal disease and cancer, with a focus on those studies conducted in the years following the Joint European Federation of Periodontology/American Academy of Periodontology Workshop on “Periodontitis and Systemic Diseases” in November 2012. This review also explores the role of chronic inflammation as a biologically plausible mechanistic link between periodontal disease and risk of cancer. Furthermore, it highlights studies that have examined the potential importance of certain periodontal pathogens in this association.

Inhibitory effect of omega-3 fatty acids on alveolar bone resorption and osteoclast differentiation

In this study, a Porphyromonas gingivalis (P.g.)-infected mouse periodontitis model was used to investigate the effect of omega-3 fatty acid intake on differentiation and maturation of cultured osteoclast. Four-week-old C57BL/6JJcl mice were divided into four groups according to the diets they were fed from the beginning of the experiment (i.e., food containing omega-3 or omega-6 fatty acids) and whether they were orally administered P.g. Thirty-three days after beginning the experiment, bone marrow cells were sampled from the femoral bone of mice from each group and differentiated into osteoclasts; the effects of the ingestion of different fatty acids were subsequently investigated. There was no statistical interaction between the different fatty acids and P.g. infection on the number of osteoclasts (P = 0.6). However, the fatty acid type affected the number of osteoclasts in mice (P = 0.0013), with the omega-3 groups demonstrating lower osteoclast numbers than the omega-6 groups. Furthermore, the addition of resolvin E1 (RvE1), which is an omega-3 fatty acid-derived lipid mediator, suppressed the differentiation of mouse cultured osteoclasts (P < 0.0001). Therefore, the ingestion of omega-3 fatty acids may suppress osteoclast differentiation while inhibiting bone resorption and tissue destruction due to periodontitis.

Clinical and Biochemical Evaluation of the Effect of Diode Laser Treatment Compared to the Non-surgical and Surgical Treatment of Periodontal Diseases

Background:

Periodontal therapy consists of eliminating the inflammation, treating periodontal pockets, motivating the patient for oral hygiene, and, if necessary, for surgical treatment. Recently, the application of a diode laser is widely being investigated for periodontal disease treatment.

Objective:

The analysis and evaluation of the clinical and biochemical impact of diode laser periodontal treatment, compared to either surgical or non-surgical, therapy, was the aim of this study.

Methods:

The study involved 80 patients older than 18 with at least 20 teeth. Evaluation of periodontal parameters was done conveniently on a single-rooted tooth (incisive, canine, premolar) on six surfaces, before the start of periodontal therapy, and after three, and six months. The laser used in the study was a diode laser with a wavelength of 980 nm. Digital X-rays were taken for bone level evaluation before and after the treatment. The presence of a bone destruction mediator (Matrix metalloproteinase-8 - MMP-8) was evaluated by the dipstick immunoassay test. Biochemical analysis and radiographic measurements were evaluated at the baseline and six months after the treatment. The statistical analysis included χ2-test and one-way ANOVA.

Results:

The results of this study showed that diode laser treatment was more effective in reducing periodontal clinical parameters, lowering MMP-8 levels and reducing the bone loss, compared to the group treated with scaling and root planning, or with a surgical approach.

Conclusion:

Diode laser may be considered as an effective alternative for periodontal treatment, with benefits in clinical and biochemical parameters.

Adverse effects of electronic cigarettes on the disease-naive oral microbiome

Six percent of Americans, including 3 million high schoolers, use e-cigarettes, which contain potentially toxic substances, volatile organic compounds, and metals. We present the first human study on the effects of e-cigarette exposure in the oral cavity. By interrogating both immunoinflammatory responses and microbial functional dynamics, we discovered pathogen overrepresentation, higher virulence signatures, and a brisk proinflammatory signal in clinically healthy e-cigarette users, equivalent to patients with severe periodontitis. Using RNA sequencing and confocal and electron microscopy to validate these findings, we demonstrate that the carbon-rich glycol/glycerol vehicle is an important catalyst in transforming biofilm architecture within 24 hours of exposure. Last, a machine-learning classifier trained on the metagenomic signatures of e-cigarettes identified as e-cigarette users both those individuals who used e-cigarettes to quit smoking, and those who use both e-cigarettes and cigarettes. The present study questions the safety of e-cigarettes and the harm reduction narrative promoted by advertising campaigns.

A low level of lysophosphatidic acid in human gingival crevicular fluid from patients with periodontitis due to high soluble lysophospholipase activity: Its potential protective role on alveolar bone loss by periodontitis

We previously detected a submicromolar concentration of lysophosphatidic acid (LPA) in human saliva. Here, we compare LPA concentrations in human gingival crevicular fluid (GCF) from patients with periodontitis and healthy controls, and examine how the local LPA levels are regulated enzymatically. The concentrations of LPA and its precursor lysophospholipids in GCF was measured by liquid chromatography-tandem mass spectrometry. The LPA-producing and LPA-degrading enzymatic activities were measured by quantifying the liberated choline and free fatty acid, respectively. The concentration of LPA in GCF of periodontitis patients was lower than that of healthy controls, due to higher soluble lysophospholipase activity toward LPA. LPA was found to prevent survival of Sa3, a human gingival epithelium-derived tumor cell line, activate Sa3 through Ca²⁺ mobilization, and release interleukin 6 from Sa3 in vitro. Furthermore, local injection of LPA into the gingiva attenuated ligature-induced experimental alveolar bone loss induced by oral bacteria inoculation in a rat model of periodontitis in vivo. A high concentration of LPA in human GCF is necessary to maintain normal gingival epithelial integrity and function, protecting the progression of periodontitis.

Osteoclastogenesis in periodontal diseases: Possible mediators and mechanisms

BACKGROUND

Periodontitis is the inflammation of the tooth-supporting structures and is one of the most common diseases of the oral cavity. The outcome of periodontal infections is tooth loss due to a lack of alveolar bone support. Osteoclasts are giant, multi-nucleated, and bone-resorbing cells that are central for many osteolytic diseases, including periodontitis. Receptor activator of nuclear factor-kB ligand (RANKL) is the principal factor involved in osteoclast differentiation, activation, and survival. However, under pathological conditions, a variety of pro-inflammatory cytokines secreted by activated immune cells also contribute to osteoclast differentiation and activity. Lipopolysaccharide (LPS) is a vital component of the outer membrane of the Gram-negative bacteria. It binds to the Toll-like receptors (TLRs) expressed in many cells and elicits an immune response.

HIGHLIGHTS

The presence of bacterial LPS in the periodontal area stimulates the secretion of RANKL as well as other inflammatory mediators, activating the process of osteoclastogenesis. RANKL, either independently or synergistically with LPS, can regulate osteoclastogenesis, while LPS alone cannot. MicroRNA, IL-22, M1/M2 macrophages, and memory B cells have recently been shown to modulate osteoclastogenesis in periodontal diseases.

CONCLUSION

In this review, we summarize the mechanism of osteoclastogenesis accompanying periodontal diseases at the cellular level. We discuss a) the effects of LPS/TLR signaling and other cytokines on RANKL-dependent and -independent mechanisms involved in osteoclastogenesis; b) the recently identified role of several endogenous factors such as miRNA, IL-22, M1/M2 macrophages, and memory B cells in regulating osteoclastogenesis during periodontal pathogenesis.

Carotenoids and Periodontal Infection

Periodontitis is a polymicrobial infectious disease that leads to inflammation of the gingiva, resulting in teeth loss by various causes such as inflammation-mediated bone resorption. Recently, many investigators have reported that the periodontitis resulting from persistent low-grade infection of Gram-negative bacteria such as Porphyromonas gingivalis (Pg) is associated with increased atherosclerosis, diabetes mellitus, and other systemic diseases through blood stream. On the other hand, carotenoids belong among phytochemicals that are responsible for different colors of the foods. It is important to examine whether carotenoids are effective to the inhibition of periodontal infection/inflammation cascades. This review summarizes the advanced state of knowledge about suppression of periodontal infection by several carotenoids. A series of findings suggest that carotenoids intake may provide novel strategy for periodontitis treatment, although further study will be needed.

Sequencing of Porphyromonas gingivalis from saliva in patients with periodontitis and type 2 diabetes mellitus

Background

Porphyromonas gingivalis is a major periodontal pathogen. Saliva is the most easy, non-invasive microbiological sample for detection of periodontal pathogens.

Aim and Objectives

A prospective study on 37 diabetic patients was grouped into well-controlled diabetes with/without periodontitis and uncontrolled diabetic with periodontitis. PCR and sequencing of P. gingivalis was performed in saliva samples.

Materials and Methods

DNA was extracted from saliva using Triton X-100 and 16s rRNA gene (404 bp) was amplified by polymerase chain reaction. DNA sequencing was performed for two samples.

Results

P. gingivalis was detected in 27.03% (n = 10), of which 30% (n = 9) were diabetic with periodontal disease and 14.3% (n = 1) were diabetic without periodontal disease. The percentage of poor oral hygiene was 50% and 20% in uncontrolled and controlled glycaemic patients, respectively. DNA sequencing of two samples showed 100% identity with the sequences in the GenBank database (Gen Bank accession no: KX640913-KX640914).

Conclusion

Type 2 diabetes mellitus and periodontitis are interlinked. Early detection of P. gingivalis and appropriate treatment with doxycycline will also assist in controlling the glycaemic status.

Shockwave Therapy Efficiently Cures Multispecies Chronic Periodontitis in a Humanized Rat Model

Biofilms are ubiquitous in nature and are invariably associated with health and diseases of all living beings. Periodontal diseases & dental caries are the most prevalent conditions in which biofilm has established as a primary causative factor. Managing poly-microbial biofilm is the mainstay of periodontal therapy. Plethora of antimicrobials have been used till date to combat biofilm, but the emergence of antibiotic tolerance and resistance in biofilms is a major cause of concern. Apart from use of antimicrobials, various anti-biofilm strategies have evolved which include the use of mechanical, and chemical means to disrupt biofilms. However, none of these approaches have led to desired or optimal biofilm control and hence search for novel approach continues. Shockwaves are used in medical practice for various therapeutic purposes and in local drug delivery, gene therapy, wound healing & regeneration. With this background, a study was designed with an attempt to explore the possibility of using the shockwave for their effect on multispecies oral biofilm development from subgingival plaque samples obtained from chronic periodontitis patients. Plaque samples from 25 patients were used to derive multispecies biofilm which were used to check the efficacy of shockwaves and antibacterial efficacy of four clinically relevant antimicrobials. Biofilms were analyzed by scanning electron microscope; atomic force microscope and their biomass was quantitated by crystal violet staining. Further, a humanized rat model of periodontitis was developed. Patient derived plaque was used to establish periodontitis in healthy rats. The model was validated by performing colony forming unit (CFU) analysis of the infected tissue. The animals were subjected to low intensity shockwaves using a hand-held shockwave generator at the site of infection. Shockwave treatment was done with or without antimicrobial application. The animals were monitored for clearance of infection and for mortality. The results show that shockwave treatment in combination with antimicrobials is significantly effective in clearing a multispecies biofilm. This also brings out the possibility of application of shockwaves in the management of oral biofilms either alone or in combination with established antimicrobial agents. With further research, safety profile validation and clinical trials, shockwaves can be an effective, novel approach in management of biofilm associated periodontal disease.

Red complex: Polymicrobial conglomerate in oral flora: A review

Oral diseases are the complex host responses composed of a broad array of inflammatory cells, and cytokines, chemokines, and mediators derived from the cells resident in the gingival tissues, as well as from the emigrating inflammatory cells. A chronic polymicrobial challenge to the local host tissues triggers this response, which under certain circumstances, and in a subset of the population, leads to the progressing soft and hard tissue destruction that characterizes periodontitis. The red complex has been proposed as a pathogenic consortium, consisting of P. gingivalis, T. denticola, and T. forsythia. This review has attempted to examine the virulence potential and determinants of these commensal opportunists.

Oral microbiological control by photodynamic action in orthodontic patients

BACKGROUND

Orthodontics involves diagnosis and treatment of dental and skeletal malocclusions. Orthodontic apparatus may repair these malocclusions but may also impair oral hygiene making patients prone to develop both periodontal diseases and caries. Antimicrobial agents may be used to prevent this.To avoid increased antimicrobial resistance to available drugs, A-PDT (Antimicrobial Photodynamic Therapy) appears as a viable alternative.

OBJECTIVE

This work aimed to evaluate the efficacy of A-PDT on reducing the number of colony forming units (CFU) through the use of phenothiazine compound (methylene blue+ toluidine blue) as a photosensitizer, associated with red LED (λ640±5ηm) irradiation in orthodontic patients.

METHODOLOGY

Twenty-one patients consented to participate in the study. Three biofilm collections were performed around the brackets and gums of the inferior central incisors; first before any intervention (Control); second after 5min of pre-irradiation and the last one immediately after AmPDT. Subsequently, a microbiological routine for microorganism growth period were performed and CFU counting after a 24h done.

RESULTS

The data showed that the AmPDT was able to reduce CFU count around 90% when compared to Control group (p=0.007) and also between the A-PDT and Photosensitizer groups (p=0.010). However, there were no differences between the Control and Photosensitizer groups.

CONCLUSION

A-PDT associated with the use of phenothiazine compounds and red LED was able to significantly reduce the number of CFUs in orthodontic patients.

Changes in oral microbial profiles associated with oral squamous cell carcinoma vs leukoplakia

AIM

Oral squamous cell carcinoma (OSCC) is the most frequently occurring cancer among head and neck SCC worldwide. The identification of novel effective biomarkers for early detection may greatly improve the survival rate and prognosis of patients with OSCC. This study aimed to identify specific oral microbial profiles associated with OSCC.

METHODS

Saliva samples were collected from oral leukoplakia (OLK) and OSCC patients (N = 6 each) and healthy controls (HC; N = 4). Total bacterial genomic DNA was isolated and 16S rRNA gene survey was performed by next-generation sequencing of the V4 region. The relative distribution of abundance for phylogenetic groups was compared among the OSCC and OLK groups.

RESULTS

The 448 operational taxonomic units detected from the libraries were classified into 133 genera, 69 families, 41 orders, 26 classes and 12 phyla. The abundance of phyla Bacteroidetes and genus Solobacterium was notably higher in the OSCC group when compared with the OLK group, whereas those of genus Streptococcus was significantly lower in the OSCC group when compared with the OLK.

CONCLUSION

These changes in the salivary microbiome may have potential applications as a novel diagnostic tool for the early detection of OSCC.

Relationship of oral conditions to the incidence of infective endocarditis in periodontitis patients with valvular heart disease: a cross-sectional study

OBJECTIVES

Infective endocarditis (IE) is a life-threatening infectious disease, but the pathogenesis of the disease remains uncertain. The objective of this study was to examine whether oral infectious conditions are associated with the occurrence of IE in valvular heart disease (VHD) patients.

MATERIALS AND METHODS

A total of 119 periodontitis (P) patients with or without VHD were enrolled, and cross-sectional analyses were performed. Patients were classified as follows: (1) mild-to-moderate P without VHD, (2) mild-to-moderate P with VHD, (3) severe P without VHD, or (4) severe P with VHD. A total of 78 VHD patients were classified as (1) VHD without IE or (2) VHD with IE. Conditional logistic regression analysis was performed to compute the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

No significant differences were observed between patients with or without VHD in oral conditions. A significant increase in the percentage of alveolar bone loss in VHD patients with IE was observed compared with that of patients without IE. The ratio of both Porphyromonas gingivalis (Pg) IgG titer > 1.68 and Pg fimA type II genotype in patients with IE was significantly higher than in patients without IE. There was a significant correlation between the occurrence of IE and clinical oral findings (number of remaining teeth: OR, 0.17; rate of alveolar bone loss > 40%: OR, 11.8).

CONCLUSIONS

VHD patients with IE might have severe periodontitis compared with patients without IE, although further investigation will be needed because this is based on only 7 VHD patients with IE.

CLINICAL RELEVANCE

The patients with IE had fewer remaining teeth, more advanced bone resorption compared with those of patients without IE. These findings suggest a possible association between the occurrence of IE and periodontal infection.

Microbiological dynamics of red complex bacteria following full-mouth air polishing in periodontally healthy subjects-a randomized clinical pilot study

OBJECTIVES

Suppression of periodontal pathogens in the oral cavity of periodontally healthy individuals may lower the risk for periodontal or periimplant diseases. Therefore, the present study aimed to analyze the effect of supragingival debridement (SD) with adjunctive full mouth glycine powder air polishing (FM-GPAP) on the prevalence of periodontal pathogens in periodontally healthy individuals.

MATERIALS AND METHODS

Eighty-seven systemically and periodontally healthy intraoral carriers of red complex bacteria, i.e., Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola or other periodontal pathogens including Aggregatibacter actinomycetemcomitans, Prevotella intermedia, and Eikenella corrodens were enrolled into the study and randomly assigned to receive SD with adjunctive FM-GPAP (test, n = 42) or SD alone (control, n = 45). In the first observation period, microbiological samples were obtained prior to, and 2, 5, and 9 days following intervention. If one of these periodontal pathogens could still not be identified, additional microbial sampling was performed after 6 and 12 weeks.

RESULTS

The prevalence of red complex bacteria was significantly reduced in the test compared to the control group following treatment (p = 0.004) and at day 9 (p = 0.031). Intragroup comparison showed a significant (test, p < 0.001; control, p ≤ 0.01) reduction in the mean prevalence in both groups from BL through day 9 with an additional significant intergroup difference (p = 0.048) at day 9. However, the initial strong reduction returned to baseline values after 6 and 12 weeks.

CONCLUSION

In periodontally healthy carriers of periodontal pathogens, FM-GPAP as an adjunct to SD transiently enhances the suppression of red complex bacteria.

CLINICAL RELEVANCE

Whether the enhanced suppression of red complex bacteria by adjunctive FM-GPAP prevents the development of periodontitis in periodontally healthy carriers requires further investigations.