Herpesvirus-bacteria synergistic interaction in periodontitis

A Smart Injectable Hydrogel with Dual Responsivity to Arginine Gingipain A and Reactive Oxygen Species for Multifunctional Therapy of Periodontitis

Distinct clinical phenotypes of periodontitis are associated with specific microbiome profiles and diverse inflammatory conditions. Current drug delivery systems face challenges in precisely modulating this dynamic microenvironment. Effective inhibition of bone resorption can only be achieved through a strategic response to bacterial infections and inflammation within the periodontal pocket, followed by prompt treatment tailored to disease severity. In this study, tannic acid (TA) is loaded into hollow mesoporous silica nanoparticles (HMSNs) that are functionalized with positively charged polyarginines (R8) and negatively charged human serum albumin (HSA). These HMSNs-R8@TA-HSA (HRT) nanoparticles are then encapsulated within an injectable Nap-Gly-Phe-Phe-Tyr-OH (NapGFFY) hydrogel (NHRT). The intermediate linker R8 can interact with both arginine gingipain A (RgpA) and reactive oxygen species (ROS), which serve as markers of bacterial infections and inflammation, respectively. HSA, arginine, TA, and nitric oxide are differentially released from the hydrogel in response to varying concentrations of RgpA and ROS, demonstrating excellent antibacterial, antioxidant, and anti-inflammatory properties. This smart RgpA/ROS dual-responsive and injectable hydrogel with multifunctional therapy provides new prospects for the management of periodontitis.

Unveiling the Etiopathogenic Role of Epstein-Barr Virus in Periodontitis

Periodontitis, a prevalent and costly oral disease, remains incompletely understood in its etiopathogenesis. The conventional model attributes it to pathogenic bacteria, but emerging evidence suggests dysbiosis involving bacteria, herpesviruses, and an exaggerated host immune response. Among herpesviruses, Epstein-Barr virus (EBV) closely links to severe periodontitis, yet the mechanisms underlying EBV-related pathogenesis remain elusive. This study examined the presence, methylation patterns, and infection states of EBV in gingival tissues from healthy patients and those with periodontitis. It also assessed gene expression differences associated with EBV through whole-genome transcriptomic profiling in healthy and periodontitis-affected tissues. EBV DNA was found at similar frequencies in healthy and periodontitis tissues, suggesting common EBV infection even before disease manifestation. In healthy tissues, mostly unmethylated EBV genomes indicated lytic infection in gums, consistent with the literature on lytic EBV spread in epithelia and continual significant virus release in the saliva of healthy carriers. Conversely, EBV DNA in periodontitis tissues showed both methylated and unmethylated patterns, suggesting a mix of latent and lytic genomes. This indicates the coexistence of latent EBV in B-cells and lytic EBV in plasma cells (PCs), linking EBV presence with both cell types in periodontitis. Whole-genome transcriptomic analysis revealed distinct expression profiles in EBV-positive periodontitis tissues, with upregulated genes associated with inflammatory/immune responses and B-cell and PC markers, while downregulated genes were related to epithelial structure and organization. The EBV-positive periodontitis signature differed distinctly from that of EBV-positive healthy gums, eliciting only a typical viral-induced immune response. These findings provide new insights into EBV physiopathology in the gum, notably assigning a direct etiopathogenetic contribution to EBV in periodontitis. The results suggest a model where EBV can commonly, and apparently asymptomatically, spread in healthy gingiva but may also aggravate inflammation in the context of gum dysbiosis, involving infiltration of B-cells and PCs and loss of epithelial integrity.

Prevalence of Epstein-Barr Virus, Cytomegalovirus, and Periodontopathic Bacteria in Patients With Periodontitis: A Case-Control Study

OBJECTIVES

Opportunistic viruses such as cytomegalovirus (CMV) and Epstein-Barr virus (EBV) have been detected in gingival crevicular fluid (GCF) and saliva of patients with periodontal disease. However, the relationship between herpesviruses and periodontitis remains obscure. The aim of this case-control study was the detection and association of CMV and EBV with periodontitis.

MATERIAL AND METHODS

Forty-eight adults were included in this study: 24 patients with periodontitis (CP) and 24 periodontally healthy individuals (HS). All patients underwent periodontal examination, including probing depth (PD), clinical attachment loss (CAL), plaque index (PI), and bleeding on probing (BOP). Subgingival biofilm samples were collected from all patients and real-time PCR was performed for viral and bacterial detection. The odds ratio (OR) was calculated, and the chi-squared test or Fisher's exact test was performed to analyze the significant differences.

RESULTS

EBV was detected only in one healthy patient meanwhile no CMV was found. No statistically significant differences were found between the periodontal clinical parameters of EBV-positive patients and the negative ones: PI (p = 0.090), PD (p = 0.857), CAL (p = 0.801), and BOP (p = 0.104). Except for Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf), Prevotella intermedia (Pi), and Treponema denticola (Td) showed a statistically significant association (p < 0.001) with the clinical periodontal parameters. Aa presence was not statistically associated with periodontal sites (p < 0.296). Tf and Pg were the most frequently detected periodontopathic bacteria in the CP group (91.7% sites).

CONCLUSION

The present case-control study showed that the prevalence of EBV and CMV did not show significant differences between the groups evaluated in the Spanish population.

Efficacy of toothpaste containing OPTIMEALTH® OR in inhibiting dental plaque and gingivitis: A randomized controlled trial

BACKGROUND

This randomized double-blind, placebo-controlled clinical trial evaluated the effects of 2% OPTIMEALTH® OR toothpaste in regulating dental plaque microbiota and alleviating gingivitis.

METHODS

Subjects were randomly assigned to the placebo group and test group. They were instructed to brush their teeth with placebo toothpaste (placebo group) or OPTIMEALTH® OR toothpaste (test group) for a continuous 4 weeks. Clinical indices of plaque index, gingival index, and bleeding on probe (%) were examined, and images of dental plaque staining were captured at baseline and after 2 and 4 weeks. The plaque microbiome was analyzed by 16s rDNA amplicon sequencing at baseline and after 4 weeks.

RESULTS

Thirty-two participants with similar characteristics were recruited. After using OPTIMEALTH® OR toothpaste for 4 weeks, a decrease of 27.05% (P < .01), 8.29% (P > .05), and 47.44% (P < .05) in plaque index, gingival index, and bleeding on probe (%) scores was observed compared to the baseline, respectively. The extent of decline in these indices is greater than that in the placebo group. A decrease in dental plaque could be observed after 2 and 4 weeks in the test group. The 16s rDNA sequencing results showed that the observed species index and Chao index, but not the Shannon index and beta diversity, were reduced significantly after using OPTIMEALTH® OR toothpaste for 4 weeks. In addition, compared with the placebo group, using OPTIMEALTH® OR toothpaste reduced the abundance of bacterial species such as Veillonella parvula and Prevotella denticola.

CONCLUSION

Brushing teeth with 2% OPTIMEALTH® OR-fortified toothpaste could effectively reduce dental plaque and regulate plaque microbiota.

Exploring the Link Between Periodontitis and Alzheimer's Disease-Could a Nanoparticulate Vaccine Break It?

Alzheimer's disease (AD) is the most prevalent neurodegenerative disorder, as approximately 55 million people worldwide are affected, with a significant tendency to increase. It reveals three main pathological features: amyloid plaques, neurofibrillary tangles, and neuroinflammation, responsible for the neurodegenerative changes that slowly lead to deterioration of personality and cognitive control. Over a century after the first case report, effective treatments remain elusive, likely due to an incomplete understanding of the precise mechanisms driving its pathogenesis. Recent studies provide growing evidence of an infectious aetiology for AD, a hypothesis reinforced by findings that amyloid beta functions as an antimicrobial peptide. Among the microorganisms already associated with AD, Porphyromonas gingivalis (Pg), the keystone pathogen of periodontitis (PeD), has received particular attention as a possible aetiological agent for AD development. Herein, we review the epidemiological and genetic evidence linking PeD and Pg to AD, highlighting the identification of periodontal bacteria in post mortem analysis of AD patients' brains and identifying putative mechanistic links relevant to the biological plausibility of the association. With the focus on AD research shifting from cure to prevention, the proposed mechanisms linking PeD to AD open the door for unravelling new prophylactic approaches able to reduce the global burden of AD. As hypothesised in this review, these could include a bionanotechnological approach involving the development of an oral nanoparticulate vaccine based on Pg-specific antigens. Such a vaccine could prevent Pg antigens from progressing to the brain and triggering AD pathology, representing a promising step toward innovative and effective AD prevention.

Impact of Periodontitis and Oral Dysbiosis Metabolites in the Modulation of Accelerating Ageing and Human Senescence

Periodontitis, a chronic multifactorial inflammatory condition of the periodontium, is originated by a dysbiotic oral microbiota and is negatively correlated with several systemic diseases. The low-chronic burden of gingival inflammation not only exacerbates periodontitis but also predisposes individuals to a spectrum of age-related conditions, including cardiovascular diseases, neurodegenerative disorders, and metabolic dysfunction, especially related to ageing. In this regard, over the local periodontal treatment, lifestyle modifications and adjunctive therapies may offer synergistic benefits in ameliorating both oral and systemic health in ageing populations. Elucidating the intricate connections between periodontitis and senescence is important for understanding oral health's systemic implications for ageing and age-related diseases. Effective management strategies targeting the oral microbiota and senescent pathways may offer novel avenues for promoting healthy ageing and preventing age-related morbidities. This review will analyze the current literature about the intricate interplay between periodontitis, oral dysbiosis, and the processes of senescence, shedding light on their collective impact on the modulation and accelerated ageing and age-related diseases. Lastly, therapeutic strategies targeting periodontitis and oral dysbiosis to mitigate senescence and its associated morbidities will be discussed.

Herpes simplex virus-induced upregulation of inflammatory cytokines in human gingival fibroblasts

Herpes simplex virus type 1 (HSV-1) is the leading pathogen in the maxillo-facial region, affecting millions of individuals worldwide. Its periodic reactivation aligns with the most common course pattern of periodontal disease. The present study used RNA sequencing to investigate the transcriptomes of human gingival fibroblasts (HGFs) following HSV-1 infection from the early to late stages (12-72 h). At the early stage of infection (12 h post-infection), the most upregulated genes were interferon (IFN) regulatory factor family members, toll-like receptor (TLR) family members, IFN-β1, interleukin (IL)-1, C-C motif ligands, chemokine (C-X-C motif) ligands (CXCLs), and tumor necrosis factor (TNF). The strongest differential expression was observed in TNF, nucleotide-binding oligomerization domain-like receptor (NLR), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways. At the late stage of infection, the most upregulated genes were CXCLs and ILs. The differentially expressed genes were divided into nine clusters, according to the time series expression trend. Next, the prominent activation of TLRs, retinoic acid-inducible gene I-like receptor signaling, NLRs, and downstream IFNAR-JAK-STAT signaling pathways were observed via a modified HSV-1 infection map. The HSV-1-induced upregulation of inflammatory cytokines in HGFs may drive inflammatory processes in periodontitis. The dynamic variations in mRNAs in HGFs from the early to late stages after HSV-1 infection can provide an analytical framework for determining the host anti-viral defense response to antagonize HSV-1 infection in periodontal tissues.

Appraising the life-course impact of Epstein-Barr virus exposure and its genetic signature on periodontitis

BACKGROUND

Periodontitis arises from a multifaceted interplay of environmental variables and genetic susceptibility, where microbial infection plays an indispensable part. Epstein-Barr virus (EBV) exposure has long been considered associated with periodontitis activity; however, the causal relationship and genetic connection between them remain unknown.

METHODS

Within a life-course context, our study employed comprehensive Mendelian randomization (MR) methods, including univariable, multivariable, Bayesian model averaging, and reverse MR, to investigate the causal association between EBV exposure and periodontitis. Additionally, linkage disequilibrium score regression and colocalization analysis were utilized to assess the cross-trait genetic correlations, followed by transcriptome-wide association and enrichment analysis to discern the genetic-phenotypic biological profiles.

RESULTS

Heightened levels of EBV antibodies, particularly early antigen diffuses (which serve as indicators of early infection or reactivation), are associated with an increased risk of periodontitis (odds ratio [OR]: 1.27 [1.09-1.47], p = 6.05 × 10-3) and demonstrate a significant genetic correlation (p = 4.11 × 10-3). This pathogenesis may involve the high-confidence causal gene RNASEK located in 17p13.1. Genetically predicted early-life anti-EBV immunoglobulin G (IgG) levels are correlated to a reduced periodontitis risk (OR: 0.89 [0.82-0.97], p = 1.76 × 10-3).

CONCLUSIONS

The present study highlights the impact of life-course EBV exposure and its genetic hallmark on periodontitis, providing novel perspectives into the underlying pathogenesis and management strategies for EBV-related periodontitis. These findings underscore diverse clinical and public health implications, encompassing antiviral therapies, viral vaccination strategies, and tailored interventions for individualized periodontitis management. Further research is required to validate and expand upon our findings.

PLAIN LANGUAGE SUMMARY

Periodontitis is a chronic inflammatory disease driven by interactions between microbial pathogens and the host immune system. While bacteria have traditionally been the focus of research, recent studies highlight the significance of virus-bacteria interactions, particularly the role of Epstein-Barr virus (EBV)-a herpesvirus infecting over 90% of the global population-in the development of periodontitis. However, the underlying causal and genetic mechanisms remain unclear. Our study employed genome-wide multi-omics approaches to investigate the link between EBV exposure and periodontitis. We found that recent EBV infection or reactivation increases the risk of periodontitis, whereas early-life exposure, possibly enabling immune resistance, may reduce it. Essential genes were identified as potential mediators, including CRTC3-AS1, HLA-DQA1, and RNASEK. These findings provide novel insights into the EBV-periodontitis connection. For example, viral testing and control could benefit patients unresponsive to standard bacterial treatments, and early viral exposure via vaccination might reduce the risk of periodontitis. Further clinical studies are required to elucidate these underlying mechanisms and the contribution of virus-bacteria interactions.

Exploring the interplay between Porphyromonas gingivalis KGP gingipain, herpes virus MicroRNA-6, and Icp4 transcript in periodontitis: Computational and clinical insights

BACKGROUND

Porphyromonas gingivalis, a major pathogen in periodontitis, produces KGP (Lys-gingipain), a cysteine protease that enhances bacterial virulence by promoting tissue invasion and immune evasion. Recent studies highlight microRNAs' role in viral latency, potentially affecting lytic replication through host mechanisms. Herpes virus (HSV) establishes latency via interactions between microRNA-6 (miRH-6) and the ICP4 transcription factor in neural ganglia. This suggests a potential link between periodontitis and HSV-induced latency. This study aims to identify and validate the insilico inhibitory interaction of P. gingivalis KGP with ICP4 transcripts and correlate the presence of viral latency-associated transcript micro-RNA-6 with periodontitis.

METHODS

Computational docking analysis was performed to investigate the potential interaction between ICP4 and KGP gingipain. The binding energy and RMSD ligand values were calculated to determine the interaction's strength. Ten patients with recurrent clinical attachment loss despite conventional therapy were included in the clinical study. Subgingival tissue samples were collected post-phase I therapy, and HSV microRNA-6 presence was detected via polymerase chain reaction and confirmed through gel electrophoresis.

RESULTS

Computational docking identified the ICP4-KGP gingipain complex with the lowest binding energy (-288.29 kJ mol^1) and an RMSD ligand of 1.5 Angstroms, indicating strong interaction potential. Gel electrophoresis confirmed miRH-6 presence in all samples.

CONCLUSION

The identification of miRNA-6 in periodontitis patients and the strong interaction potential between P. gingivalis KGP gingipain and ICP4 transcripts indicate a possible link between bacterial virulence factors and viral latency dynamics in periodontal tissues. These results highlight the complex interplay between oral pathogens, viral microRNAs, and host immune responses in periodontitis.

Association between Periodontal Disease and Oral Benign, Potentially Malignant, Malignant, and Chronic Immune-Mediated Disorders: A Clinical Study

Background: Periodontal disease is an inflammatory, chronic, and multifactorial disease. The objective of this study is to analyze the association between periodontal disease and some disorders such as papillomas (benign lesions), lichen planus (a chronic immune-mediated disorder), leukoplakia (potentially malignant lesions), and oral cancer (malignant lesions). Methods: For this study, 42 patients were recruited whose supragingival and subgingival plaque was qualitatively analyzed using a phase-contrast microscope, which allowed for the detection of compatible bacterial flora (immobile and composed mainly of cocci) indicative of periodontal health and incompatible bacterial flora (mobile and composed mainly of spirochetes) indicative of periodontal pathology. Patients with incompatible bacterial flora were then subjected to a laser-assisted periodontal treatment with irrigation with hydrogen peroxide within the periodontal pockets (a non-surgical laser-assisted periodontal protocol which is referred to as dye-free photodynamic therapy). Results: Based on the 42 patients recruited, there was no association between oral cavity lesions and periodontal pathogenic bacteria. Four of them were found to have incompatible bacterial flora. Indeed, it was found that almost all the patients had been previously instructed in the proper techniques of home oral hygiene, and more than half of them reported that they carried out periodic check-ups by a dental hygienist. Of the four patients with signs and symptoms of periodontitis, two stated a willingness to undergo the non-surgical laser-assisted periodontal protocol and showed improvements in periodontal indices such as CAL, PPD, and BoP. Conclusions: hygienists and dentists are determining factors in the prevention of periodontal disease and for the maintenance of good oral health.

The role of viruses in oral mucosal lesions

The mucosa of the oral cavity is exposed to a large number of different microorganisms such as archaea, bacteria, fungi, parasites, and viruses. Among those, viruses cause specific infections, which can easily be transmitted from one person to another. The infectious route may not only include patients and their relatives but also the dental professional team. Thus, a wide knowledge regarding specific viral infections is crucial for the daily routine. Signs and symptoms of oral viral infections can be completely absent or develop into a pronounced clinical picture, so that early detection and information determine the further course of the infection and its influence on other inflammatory diseases, such as periodontitis, as well as the safety of family members and the social environment. As the clinical manifestation of viral infections may be highly variable leading to heterogenous mucosal lesions it is, in most cases, mandatory to differentiate them by specific microbiological tests in addition to clinical examination procedures. This article will give an overview of the role of viruses infecting the oral mucosa, and in addition, describe their clinical manifestation and management.

Severe periodontitis and congenital cytomegalovirus: Cleft lip and cleft palate

Severe periodontitis lesions can harbor several hundred-thousand copies of active cytomegalovirus, and this paper proposes that cytomegalovirus in maternal periodontitis can infect the fetus. Cleft lips and palates may be oral examples of congenital cytomegalovirus infection. Anti-cytomegalovirus periodontal treatment is indicated for high-risk women who exhibit severe periodontitis and weakened immune system and are contemplating pregnancy or are in the first trimester of pregnancy.

Causal relationships of infection with Helicobacter pylori and herpesvirus on periodontitis: A Mendelian randomization study

Background

To explore the causal association between Helicobacter pylori (H. pylori) infection, herpesvirus infection and periodontitis (PD) from a genetic perspective using Mendelian randomization (MR).

Methods

The PD data were derived from genome-wide association study (GWAS) from the Dental Endpoints (GLIDE) consortium, and the FinnGen Biobank provided data on H. pylori and herpesvirus infections. In addition, we examined GWAS data for subtypes of H. pylori and herpesvirus infection. Inverse variance weighting (IVW) was selected as a major analysis technique, and weighted median (WM), weighted model, simple model, and MR-Egger regression were added as supplementary methods. To verify the findings, the effects of pleiotropy and heterogeneity were assessed.

Results

Genetically predicted H. pylori infection (OR = 0.914, 95%CI = 0.693-1.205, P = 0.523), anti-H. pylori VacA (OR = 0.973, 95%CI = 0.895-1.057, P = 0.515), anti-H. pylori CagA (OR = 1.072, 95%CI = 0.986-1.164; P = 0.102), Epstein-Barr virus (EBV) infection (OR = 1.026, 95%CI = 0.940-1.120, P = 0.567), Herpes simplex virus (HSV) infection (OR = 0.962, 95%CI = 0.883-1.048, P = 0.372), cytomegalovirus (CMV) infection (OR = 1.025, 95%CI = 0.967-1.088, P = 0.415), EBV nuclear antigen-1 (EBNA1) (OR = 1.061, 95%CI = 0.930-1.209, P = 0.378), EBV virus capsid antigen (VCA) (OR = 1.043, 95CI% = 0.890-1.222, P = 0.603), HSV-1 (OR = 1.251, 95%CI = 0.782-2.001, P = 0.351), HSV-2 (OR = 1.020, 95%CI = 0.950-1.096, P = 0.585), CMV IgG (OR = 0.990, 95CI% = 0.882-1.111, P = 0.861) were not associated with PD, indicated that H. pylori and herpesvirus infection had no causal relationship to PD. Reverse studies also found no cause effect of PD on H. pylori or herpesvirus infection. The results of the sensitivity analysis suggested the robustness of the MR results.

Conclusion

This study offered preliminary proof that H. pylori and herpesvirus infections were not causally linked to PD, and vice versa. However, more robust instrumental variables (IVs) and larger samples of GWAS data were necessary for further MR analysis.

Herpes Simplex Virus Type 1 Infection of Human Periodontal Ligament

The periodontal ligament (PDL) is a complex connective tissue that connects the tooth root to the dental alveolar bone and plays crucial mechanical roles. PDL also exhibits regenerative roles and regulatory functions to maintain periodontium integrity and homeostasis. While PDL exposure to oral microbial pathogens is common, virtually nothing is known regarding viral infections of PDL. In particular, human herpes simplex virus type 1 (HSV-1) persistently infects the oral cavity through infections of the oral epithelium, connective tissue and neurons. While the oral spread of HSV-1 is generally asymptomatic, this virus has also been implicated in various oral pathologies. In this study, using a primary cell model derived from PDL (PDL cells), and whole surgical fragments of PDL, we provide evidence supporting the efficient infection of PDL by HSV-1 and the promotion of cytopathic effects. Infection of PDL by HSV-1 was also associated with an acute innate inflammatory response, as illustrated by the production of antiviral interferons and pro-inflammatory cytokines. Furthermore, this inflammatory response to HSV-1 was exacerbated in the presence of bacterial-derived products, such as peptidoglycans. This work therefore highlights the ability of HSV-1 to infect mesenchymal cells from PDL, suggesting that PDL may serve as a viral reservoir for the periodontal spread of HSV-1. Moreover, this raises questions about HSV-1 oral pathogenesis, as HSV-1-associated cytopathic and inflammatory effects may contribute to profound alterations of PDL integrity and functioning.

Effects of Green Tea Extract Epigallocatechin-3-Gallate on Oral Diseases: A Narrative Review

OBJECTIVES

Oral diseases are among the most prevalent diseases globally. Accumulating new evidence suggests considerable benefits of epigallocatechin-3-gallate (EGCG) for oral health. This review aims to explore the role and application of EGCG in main oral diseases.

METHODS

This narrative review thoroughly examines and summarizes the most recent literature available in scientific databases (PubMed, Web of Science, Scopus, and Google Scholar) reporting advances in the role and application of EGCG within the dental field. The major keywords used included "EGCG", "green tea extract", "oral health", "caries", "pulpitis", "periapical disease", "periodontal disease", "oral mucosa", "salivary gland", and "oral cancer".

CONCLUSIONS

EGCG prevents and manages various oral diseases through its antibacterial, anti-inflammatory, antioxidant, and antitumor properties. Compared to traditional treatments, EGCG generally exhibits lower tissue irritation and positive synergistic effects when combined with other therapies. Novel delivery systems or chemical modifications can significantly enhance EGCG's bioavailability, prolong its action, and reduce toxicity, which are current hotspots in developing new materials.

CLINICAL SIGNIFICANCE

this review provides an exhaustive overview of the biological activities of EGCG to major oral diseases, alongside an exploration of applications and limitations, which serves as a reference for preventing and managing oral ailments.

Elevated subgingival temperature infers high bacterial pathogen counts in severe periodontitis

OBJECTIVES

Periodontal inflammation may be assessed by bleeding on probing and subgingival temperature. This pilot study evaluated the intrapatient relationship between subgingival temperature and selected bacterial groups/species in deep periodontal pockets with bleeding on probing.

MATERIALS AND METHODS

In each of eight adults, an electronic temperature probe identified three "hot" pockets with elevated subgingival temperature and three "cool" pockets with normal subgingival temperature among premolars/molars with 6‒10 mm probing depths and bleeding on probing. Microbial samples collected separately from the hot and cool periodontal pockets were cultured for selected periodontal pathogens.

RESULTS

Hot compared to cool periodontal pockets revealed significantly higher absolute and normalized subgingival temperatures and yielded higher mean proportions of Porphyromonas gingivalis (10.2% for hot vs. 2.5% for cool, p = 0.030) and total red/orange complex periodontal pathogens (48.0% for hot vs. 24.6% for cool, p = 0.012).

CONCLUSIONS

Hot versus cool deep periodontal pockets harbored significantly higher levels of major periodontal pathogens. Subgingival temperature measurements may potentially be useful to assess risk of periodontitis progression and the efficacy of periodontal therapy.

Epstein-Barr Virus Promotes Inflammatory Cytokine Production in Human Gingival Fibroblasts

BACKGROUND

Periodontitis is one of the most common chronic oral inflammatory diseases. Over the past decade, herpes viruses, particularly Epstein-Barr virus (EBV), have been considered promising pathogenic candidates for periodontitis. However, the specific mechanism by which EBV contributes to the development of periodontitis is still unknown. This study aimed to explore the mechanism of EBV underlying the inflammatory response in human gingival fibroblasts (HGFs).

MATERIALS AND METHODS

HGFs were stimulated with different concentrations of EBV (104, 105, 106, 107, and 108 DNA copies/mL) for 0, 8, 24, or 48 hours. The mRNA levels of interleukin (IL)-1β, tumour necrosis factor-α (TNF-α), IL-8, monocyte chemoattractant protein-1 (MCP-1), and Toll-like receptor 9 (TLR9) were measured using quantitative real-time polymerase chain reaction (PCR). Enzyme-linked immunosorbent assays (ELISAs) were performed for determining the mRNA and protein levels of IL-1β, TNF-α, IL-8, and MCP-1. Real-time PCR and ELISA were performed to determine the protein levels of IL-1β, TNF-α, IL-8, and MCP-1. Activation of the TLR9/myeloid differentiation factor 88 (MyD88)/nuclear factor kappa B (NF-κB) pathway was evaluated using western blotting.

RESULTS

The expressions of IL-1β, TNF-α, IL-8, and MCP-1 were significantly upregulated in HGFs under EBV stimulation in a concentration- and time-dependent manner. EBV promoted TLR9 and MyD88 expression and induced NF-κB transcription. On the contrary, the upregulation of these factors and the activation of NF-κB pathway were drastically inhibited by TLR9 antagonists.

CONCLUSIONS

Our findings demonstrate that EBV promotes the production of inflammatory cytokines IL-1β and TNF-α and chemokines IL-8 and MCP-1 in HGFs through the TLR9/MyD88/NF-κB pathway.

A Low-Cost Protocol Using the Adjunctive Action of Povidone-Iodine Irrigations and Sodium Hypochlorite Rinsing Solution in Step 2 of Periodontal Therapy for Patients with Stage III-IV Periodontitis: A Single-Blind, Randomized Controlled Trial

In severe stages of periodontitis, conventional periodontal therapy and maintenance care are usually insufficient due to the viral and bacterial etiology; thus, a mechanical approach alone may not be sufficient to eliminate a substantial portion of subgingival pathogens, especially in deep periodontal sites. Background and Objectives: This single-blind, randomized clinical trial aimed to compare the clinical and microbiological efficacy of a low-cost protocol using povidone-iodine and sodium hypochlorite formulations as adjuncts to non-surgical therapy for patients with stage IV periodontitis when compared with chlorhexidine, the most commonly employed substance to date for antimicrobial regimens in periodontal therapy. Materials and Methods: Forty-five patients were randomly divided into two groups: control (subgingival instrumentation, chlorhexidine-assisted) and test (antiviral medication, subgingival instrumentation with povidone-iodine, sodium hypochlorite rinsing solution, and antibiotics). Clinical measurements and microbiological analyses were performed at baseline and after three months. Results: After three months, notable differences were found in the bacterial detection scores for Porphyromonas gingivalis (a significant reduction in detection frequency was observed in the test compared to the control (p = 0.021)), and there were significant reductions in detection in the test group for Tannerella forsythia and Treponema denticola, showing undetectable levels (p < 0.0001 for both). In the test group, the pocket probing depth median value was reduced significantly (p = 0.0005); similarly, bleeding on probing showed a marked decrease (p < 0.0001). However, changes in clinical attachment loss and full-mouth plaque score were not statistically significant. Conclusions: Using the proposed protocol, substantial improvements in clinical and microbiological parameters were obtained when compared with the current antimicrobial recommendations.

A review and new perspective on oral bacteriophages: manifestations in the ecology of oral diseases

Objective

To explore the manifestations of bacteriophages in different oral disease ecologies, including periodontal diseases, dental caries, endodontic infections, and oral cancer, as well as to propel phage therapy for safer and more effective clinical application in the field of dentistry.

Methods

In this literature review, we outlined interactions between bacteriophages, bacteria and even oral cells in the oral ecosystem, especially in disease states. We also analyzed the current status and future prospects of phage therapy in the perspective of different oral diseases.

Results

Various oral bacteriophages targeting at periodontal pathogens as Porphyromonas gingivalis, Fusobacterium nucleatum, Treponema denticola and Aggregatibacter actinomycetemcomitans, cariogenic pathogen Streptococcus mutans, endodontic pathogen Enterococcus faecalis were predicted or isolated, providing promising options for phage therapy. In the realm of oral cancer, aside from displaying tumor antigens or participating in tumor-targeted therapies, phage-like particle vaccines demonstrated the potential to prevent oral infections caused by human papillomaviruses (HPVs) associated with head-and-neck cancers.

Conclusion

Due to their intricate interactions with bacteria and oral cells, bacteriophages are closely linked to the progression and regression of diverse oral diseases. And there is an urgent need for research to explore additional possibilities of bacteriophages in the management of oral diseases.

Herpes simplex virus type 1 in periapical pathoses: Systematic review and meta-analysis

OBJECTIVES

The objective of this systematic review and meta-analysis of observational studies was to assess whether herpes simplex virus type 1 (HSV-1) can infect endodontic periapical lesions.

MATERIALS AND METHODS

Studies with cross-sectional design investigating HSV-1 in periapical tissues of patients with symptomatic and asymptomatic acute and chronic apical periodontitis were searched through MEDLINE, Scopus, Embase, Web of Science, and Google Scholar. Pooled HSV-1 prevalence proportion with 95% confidence interval (95CI) in periapical lesions was assessed with both fixed-effect and random-effects models, with/without adjustment for study quality and publication bias. Result robustness was investigated through sensitivity and subgroup analyses.

RESULTS

Literature search, performed twice, provided 84 items, and eight remained for the meta-analysis; globally, there were 194 patients mostly adults. The pooled HSV-1 prevalence proportions, assessed with various methods, were 6.9% (95CI, 3.8-11.3%, fixed-effect); 6.8% (95CI, 3.6-11.0%, random-effects); 8.1% (95CI, 4.4-14.5%, quality-adjusted); and 4.8% (95CI, 2.0-11.4%; adjusted for small-study effect).

CONCLUSIONS

The results indicated that HSV-1 can colonize the periapical tissues of 3%-11% patients with periapical diseases. Such data do not imply a causative role of HSV-1 in disease development and advancement. Well-designed and large-sized prospective cohort studies should be added in the literature panorama.

Microbes translocation from oral cavity to nasopharyngeal carcinoma in patients

The presence of oral microbes in extra-oral sites is linked to gastrointestinal cancers. However, their potential ectopically colonization in the nasopharynx and impact on local cancer development remains uncertain. Our study involving paired nasopharyngeal-oral microbial samples from nasopharyngeal carcinoma (NPC) patients and controls unveils an aberrant oral-to-nasopharyngeal microbial translocation associated with increased NPC risk (OR = 4.51, P = 0.012). Thirteen species are classified as oral-translocated and enriched in NPC patients. Among these, Fusobacterium nucleatum and Prevotella intermedia are validated through culturomics and clonal strain identification. Nasopharyngeal biopsy meta-transcriptomes confirm these microbes within tumors, influencing local microenvironment and cytokine response. These microbes correlate significantly with the Epstein-Barr virus (EBV) loads in the nasopharynx, exhibiting an increased dose-response relationship. Collectively, our study identifies oral microbes migrating to the nasopharynx, infiltrating tumors, impacting microenvironments and linking with EBV infection. These results enhance our understanding of abnormal microbial communication and their roles in carcinogenesis.

Herpesvirus-Bacteria pathogenic interaction in juvenile (aggressive) periodontitis. A novel etiologic concept of the disease

Localized juvenile (aggressive) periodontitis starts at puberty in otherwise healthy individuals and involves the proximal surfaces of permanent incisors and first molars. The disease destroys a sizeable amount of periodontal bone within a few months despite minimal dental plaque and gingival tissue inflammation. Cytomegalovirus and Epstein-Barr virus, as well as the two main periodontopathic bacteria Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis, are linked to juvenile periodontitis. Juvenile periodontitis-affected teeth show cementum hypoplasia. We hypothesize that an active herpesvirus infection, at the time of root formation, hampers cementum formation and, at puberty, herpesvirus reactivation triggers an upgrowth of bacterial pathogens which produce rapid periodontal destruction on teeth with a defective periodontium. A pathogenic interaction between active herpesviruses and bacterial pathogens can potentially explain the etiology and incisor-first molar destructive pattern of juvenile periodontitis. Effective treatment of juvenile periodontitis may target the herpesvirus-bacteria co-infection.

Systemic ciprofloxacin treatment of multidrug-resistant Aggregatibacter actinomycetemcomitans in severe periodontitis

An adult periodontitis patient treated with mechanical/surgical therapy experienced gingival necrosis and granulomas post-treatment. Aggregatibacter actinomycetemcomitans, a tissue-invasive pathogen, was recovered and multidrug-resistant but susceptible to ciprofloxacin. Systemic ciprofloxacin eliminated A. actinomycetemcomitans with marked clinical improvement. Ciprofloxacin may be prescribed for A. actinomycetemcomitans periodontal infection unresponsive to the common amoxicillin-metronidazole treatment.

Detection of Epstein-Barr virus infection in primary junctional epithelial cell cultures

Background

Junctional epithelium (JE) provides the front-line defense against pathogens invading periodontium. The breakdown of the JE barrier is the hallmark of periodontitis. Recent studies have implicated the Epstein-Barr virus (EBV) as one of the etiopathogenetic factors of periodontitis. EBV exhibits tropism for two target cells in vivo: B cells, where it primarily remains latent, and epithelial cells, where viral replication occurs.

Objective

Our knowledge of junctional epithelial cell (JEC) infection with EBV has been limited by the difficulty of generating cell cultures and the inability to infect JECs in vitro readily.

Design

To study EBV infection in JECs, we developed human JEC cultures derived from a periodontitis patient. Furthermore, we established a successful contact-free co-culture infection model between the EBV-donor B95-8 cell line and the EBV-permissive JEC culture. JECs and EBV infection of JECs were detected using immunofluorescent staining of cytokeratin 19 and EBNA1, respectively. In addition, EBV infection was confirmed by RT-qPCR for EBNA1, LMP1, and BZLF1 expression.

Results and conclusions

Our results suggest that the infection of JECs with EBV can occur in an in vitro experimental model. These outcomes have the potential to enhance our understanding of EBV's involvement in periodontitis and advance periodontal research.

Analysis of microbiocenosis of a gingival sulcus and periodontal pockets of patients with periodontal diseases associated with systemic pathology

Aim: The aim is to analyze the microbiome of gingival sulcus and periodontal pockets of patients with periodontal disease associated with systemic diseases. Methods: A microbiological study was conducted to analyze the microflora of the periodontal pockets in patients with different systemic pathologies and periodontal diseases. Plaque samples were collected from the gingival sulcus and periodontal pockets, and they were subsequently cultured on nutrient medium and glass plates. Results: The microbiota of the gingival sulcus and periodontal pockets in patients with associated systemic diseases in combination with periodontal disease was studied. The frequency of detecting the qualitative composition of the microbiota in the periodontal niche of patients with periodontal diseases and systemic diseases was determined. The research paper outlined groups of microorganisms isolated from periodontal pockets of patients with periodontal and systemic diseases. Conclusions: The degree of colonization by microorganisms differed slightly, while the frequency of detection of specific populations of opportunistic bacteria increased in chronic generalized periodontitis compared to chronic catarrhal gingivitis.

The effect of antipsychotic medication and the associated hyperprolactinemia as a risk factor for periodontal diseases in schizophrenic patients: a cohort retrospective study

BACKGROUND

Periodontal disease is a major health problem that results in tooth loss and thus affects oral health, which affects quality of life. In particular, schizophrenic patients are at higher risk for periodontal disease due to several factors, including the effect of antipsychotic medications received by those patients. Accordingly, the aim of the present cohort retrospective study is to explore the effect of antipsychotics on periodontal health and the possible effect of antipsychotic-induced hyperprolactinemia as a risk factor for periodontal disease progression in schizophrenic patients.

METHODS AND OUTCOMES

The study population consisted of three groups: Group A (n = 21): schizophrenic patients that have been taking "prolactin-inducing" antipsychotics for at least 1 year; Group B (n = 21): schizophrenic patients who have been taking "prolactin-sparing" antipsychotics for at least 1 year; and Group C (n = 22): newly diagnosed schizophrenic patients and/or patients who did not receive any psychiatric treatment for at least 1 year. The study groups underwent assessment of periodontal conditions in terms of pocket depth (PD), clinical attachment loss (CAL), gingival recession, tooth mobility, and bleeding on probing (BOP). Also, bone mineral density was evaluated using DEXA scans, and the serum prolactin level was measured by automated immunoassay.

RESULTS

Results revealed a statistically significant difference in PD, CAL, and serum prolactin levels (P ≤ 0.001, P = 0.001, and P ≤ 0.001, respectively) among the 3 study groups. For both PD and CAL measurements, group A has shown significantly higher values than both groups B and C, whereas there was no statistically significant difference between the values of groups C and B. Concerning serum prolactin levels, group A had significantly higher values than groups B and C (P ≤ 0.001 and P ≤ 0.001 respectively). There was a statistically significant difference (P ≤ 0.001) between the 3 study groups in terms of bone mineral density. Moreover, there was a statistically significant direct relation between serum prolactin level and other parameters including clinical attachment loss, pocket depth measurements and bone mineral density.

CONCLUSION

According to our results, it could be concluded that all antipsychotics contribute to the progression of periodontal disease, with a higher risk for prolactin-inducing antipsychotics. However, further long term, large sampled, interventional and controlled studies are required to reach definitive guidelines to allow clinicians properly manage this group of patients.

Association between human herpes simplex virus and periodontitis: results from the continuous National Health and Nutrition Examination Survey 2009-2014

BACKGROUND

Periodontitis is a common chronic oral disease which seriously affects people's quality of life. Although human herpes simplex virus (HSV) is also found in periodontal lesions, the association between HSV infection and periodontitis is unclear.

METHODS

The National Health and Nutrition Examination Survey (NHANES) data for 2009-2010, 2011-2012 and 2013-2014 was combined, and the association between HSV infection and periodontitis in the general population and particular subgroups was investigated through weighted multi-logistic analyses.

RESULTS

There were 4,733 participants aged 30-50 years old with clinically assessed periodontitis concurrent with HSV infection. In general analysis, after adjusted for covariates, both HSV-1 (OR = 1.09, P < 0.001) and HSV-2 (OR = 1.06, P = 0.030) infection was significantly associated with periodontitis. In subgroup analyses, compared with patients without HSV infection, patients with HSV-1( +) & HSV-2( +) and HSV-1( +) & HSV-2(-) infection showed higher risk of periodontitis in all subgroups (OR = 1.15, OR = 1.09, P < 0.001), while patients with HSV-1(-) & HSV-2( +) infection showed higher risk of and periodontitis only in the subgroup of people aged 40-50 years (OR = 1.10, P = 0.032) and the Mexican-American subgroup (OR = 1.35, P = 0.042). When only severe periodontitis is considered, HSV infection was associated with periodontitis, no matter the patient was infected with either of the virus or both.

CONCLUSIONS

HSV-1 infection was significantly associated with periodontitis and severe periodontitis, while HSV-2 infection was associated with severe periodontitis, and periodontitis in 40-50-year-olds and Mexican-Americans.

Association of chronic periodontitis with multiple sclerosis: A systematic review and meta-analysis

BACKGROUND

Chronic periodontitis (CP) is a multifactorial, chronic inflammatory disease of microbial etiology that manifests as a result of the dysfunction of the immune mechanism, culminating in the destruction of the alveolar bone of the jaws. Multiple sclerosis (MS) is an autoimmune disorder that affects the central nervous system (CNS), leads to demyelination and degeneration of nerve axons and often causes severe physical and/or cognitive impairment. As CP and MS involve inflammatory mechanisms and immune dysfunction, researchers have attempted to study the association between them.

AIM

To systematically review the literature on the epidemiological association between CP and MS in adults.

METHODS

PRISMA 2020 statement was used in the study protocol. The design was done according to the Cochrane methodology. A comprehensive literature search was performed in PubMed, Scopus and Cochrane databases; a manual search and evaluation of the gray literature was also performed. The meta-analysis was performed by Review Manager (RevMan) 5.4. Odds ratio (OR) with 95% confidence interval (CI) was defined as the effect size of the outcome. Heterogeneity was assessed by Chi-square and I2. The articles evaluated were written in English, without a time limit, concern observational studies (patient-controls) and report the diagnostic criteria of the diseases. Duplicate entries were excluded. To evaluate the reliability of the results of each study, Newcastle-Ottawa Scale (NOS) and GRADE tools were used. Two independent reviewers did all evaluations with a resolution of discrepancies by a third.

RESULTS

Meta-analysis included three observation studies examined 3376 people. MS patients are significantly more likely to be diagnosed with CP than healthy controls (OR 1.93, 95% CI 1.54-2.42, p<0.0001).

CONCLUSION

A high prevalence of CP was found among MS patients compared with healthy controls. Healthcare professionals should be aware of the association between these pathological entities to provide patients with high-quality care through an effective and holistic diagnostic and therapeutic approach.

Oral microbial changes and oral disease management before and after the treatment of hematological malignancies: a narrative review

OBJECTIVES

Patients with hematological malignancies have dynamic changes in oral microbial communities before and after treatment. This narrative review describes the changes in oral microbial composition and diversity, and discusses an oral microbe-oriented strategy for oral disease management.

MATERIALS AND METHODS

A literature search was performed in PubMed/Medline, Web of Science, and Embase for articles published between 1980 and 2022. Any articles on the changes in oral microbial communities in patients with hematological malignancies and their effects on disease progression and prognosis were included.

RESULTS

Oral sample detection and oral microbial sequencing analysis of patients with hematological malignancies showed a correlation between changes in oral microbial composition and diversity and disease progression and prognosis. The possible pathogenic mechanism of oral microbial disorders is the impairment of mucosal barrier function and microbial translocation. Probiotic strategies, antibiotic strategies, and professional oral care strategies targeting the oral microbiota can effectively reduce the risk of oral complications and the grade of severity in patients with hematological malignancies.

CLINICAL RELEVANCE

This review provides dentists and hematologists with a comprehensive understanding of the host-microbe associated with hematologic malignancies and oral disease management advice.

Periodontitis and COVID-19: Immunological Characteristics, Related Pathways, and Association

Both periodontitis and Coronavirus disease 2019 (COVID-19) pose grave threats to public health and social order, endanger human life, and place a significant financial strain on the global healthcare system. Since the COVID-19 pandemic, mounting research has revealed a link between COVID-19 and periodontitis. It is critical to comprehend the immunological mechanisms of the two illnesses as well as their immunological interaction. Much evidence showed that there are many similar inflammatory pathways between periodontitis and COVID-19, such as NF-κB pathway, NLRP3/IL-1β pathway, and IL-6 signaling pathway. Common risk factors such as gender, lifestyle, and comorbidities contribute to the severity of both diseases. Revealing the internal relationship between the two diseases is conducive to the treatment of the two diseases in an emergency period. It is also critical to maintain good oral hygiene and a positive attitude during treatment. This review covers four main areas: immunological mechanisms, common risk factors, evidence of the association between the two diseases, and possible interventions and potential targets. These will provide potential ideas for drug development and clinical treatment of the two diseases.

Antimicrobial Chemotherapy for Recalcitrant Severe Human Periodontitis

This study evaluated a combined systemic and topical anti-infective periodontal treatment of 35 adults who had experienced ongoing periodontal breakdown following conventional surgical periodontics. The prescribed anti-infective therapy, based on microbiological testing, consisted of a single course of metronidazole plus ciprofloxacin (23 patients), metronidazole plus amoxicillin/clavulanic acid (10 patients), and metronidazole plus ciprofloxacin followed by metronidazole plus amoxicillin/clavulanic acid (2 patients). In addition, the study patients received 0.1% povidone-iodine subgingival disinfection during non-surgical root debridement and daily patient administered oral irrigation with 0.1% sodium hypochlorite. At 1 and 5 years post-treatment, all study patients showed gains in clinical periodontal attachment with no further attachment loss, and significant decreases in pocket probing depth, bleeding on probing, and subgingival temperature. The greatest disease resolution occurred in patients who at baseline harbored predominantly major periodontal pathogens which post-antibiotics became non-detectable and substituted by non-periodontopathic viridans streptococci. The personalized and minimally invasive anti-infective treatment regimen described here controlled periodontitis disease activity and markedly improved the clinical and microbiological status of the refractory periodontitis patients.

Relevant mechanisms of MAIT cells involved in the pathogenesis of periodontitis

Mucosal-associated invariant T (MAIT) cells are a group of unconventional T cells that are abundant in the human body, recognize microbial-derived vitamin B metabolites presented by MHC class I-related protein 1 (MR1), and rapidly produce proinflammatory cytokines, which are widely involved in the immune response to various infectious diseases. In the oral mucosa, MAIT cells tend to accumulate near the mucosal basal lamina and are more inclined to secrete IL-17 when activated. Periodontitis is a group of diseases that manifests mainly as inflammation of the gums and resorption of the alveolar bone due to periodontal tissue invasion by plaque bacteria on the dental surface. The course of periodontitis is often accompanied by a T-cell-mediated immune response. This paper discussed the pathogenesis of periodontitis and the potential contribution of MAIT cells to periodontitis.

Entamoeba gingivalis is associated with periodontal conditions in Chinese young patients: A cross-sectional study

Background

This study investigated the prevalence and relative abundance of Entamoeba gingivalis (E. gingivalis) in Chinese young patients with different periodontal conditions, and its association with subgingival microbial composition, periodontal parameters, and cytokines in gingival crevicular fluid.

Methods

Participants (age: 18–45 years) diagnosed with stage II–IV periodontitis, gingivitis, or periodontal health underwent periodontal examination and sampling. Subgingival plaque was analyzed by 16S+18S sequencing for E. gingivalis detection and microbial analysis. The distribution of E. gingivalis in subgingival plaque was illustrated by fluorescence in situ hybridization. Interleukin-1β, interleukin-8, and tumor necrosis factor-α in gingival crevicular fluid were measured by multiplexed flow cytometric assay.

Results

This cross-sectional study included 120 sites from 60 participants. The prevalence and relative abundance of E. gingivalis were significantly increased in periodontitis (p<0.05). The sites were classified into three subgroups according to the relative abundance of E. gingivalis: negative group (Eg0, n=56); low-abundance group (Eg1, n=32); and high-abundance group (Eg2, n=32). The subgingival microflora in the subgroups showed stepwise changes at both the phylum and genus levels. The microflora compositions were significantly altered from Eg0 to Eg2 (p<0.001). Co-occurrence network analysis showed that Porphyromonas, Treponema, Tannerella, Filifactor, TG5, and Desulfobulbus were highly correlated with E. gingivalis (r>0.6, p<0.001). Correlation analysis showed that E. gingivalis was closely associated with important periodontal parameters and cytokines (p<0.01).

Conclusion

E. gingivalis was enriched in periodontitis and closely associated with subgingival microbial dysbiosis, periodontal parameters and cytokines in gingival crevicular fluid. Thus, it may be an important pathogen in periodontal disease.

Whole genome resequencing reveals signatures of rapid selection in a virus-affected commercial fishery

Infectious diseases are recognized as one of the greatest global threats to biodiversity and ecosystem functioning. Consequently, there is a growing urgency to understand the speed at which adaptive phenotypes can evolve and spread in natural populations to inform future management. Here we provide evidence of rapid genomic changes in wild Australian blacklip abalone (Haliotis rubra) following a major population crash associated with an infectious disease. Genome scans on H. rubra were performed using pooled whole genome resequencing data from commercial fishing stocks varying in historical exposure to haliotid herpesvirus-1 (HaHV-1). Approximately 25,000 single nucleotide polymorphism loci associated with virus exposure were identified, many of which mapped to genes known to contribute to HaHV-1 immunity in the New Zealand pāua (Haliotis iris) and herpesvirus response pathways in haliotids and other animal systems. These findings indicate genetic changes across a single generation in H. rubra fishing stocks decimated by HaHV-1, with stock recovery potentially determined by rapid evolutionary changes leading to virus resistance. This is a novel example of apparently rapid adaptation in natural populations of a nonmodel marine organism, highlighting the pace at which selection can potentially act to counter disease in wildlife communities.

Interconnection of periodontal disease and comorbidities: Evidence, mechanisms, and implications

Periodontitis, a microbiome-driven inflammatory disease of the tooth-attachment apparatus, is epidemiologically linked with other disorders, including cardio-metabolic, cognitive neurodegenerative and autoimmune diseases, respiratory infections, and certain cancers. These associations may, in part, be causal, as suggested by interventional studies showing that local treatment of periodontitis reduces systemic inflammation and surrogate markers of comorbid diseases. The potential cause-and-effect connection between periodontitis and comorbidities is corroborated by studies in preclinical models of disease, which additionally provided mechanistic insights into these associations. This overview discusses recent advances in our understanding of the periodontitis-systemic disease connection, which may potentially lead to innovative therapeutic options to reduce the risk of periodontitis-linked comorbidities.

Viruses, periodontitis, and comorbidities

Seminal studies published in the 1990s and 2000s explored connections between periodontal diseases and systemic conditions, revealing potential contributions of periodontal diseases in the initiation or worsening of systemic conditions. The resulting field of periodontal medicine led to the publication of studies indicating that periodontal diseases can influence the risk of systemic conditions, including adverse pregnancy outcomes, cardiovascular and respiratory diseases, as well as Alzheimer disease and cancers. In general, these studies hypothesized that the periodontal bacterial insult and/or the associated proinflammatory cascade could contribute to the pathogenesis of these systemic diseases. While investigations of the biological basis of the connections between periodontal diseases and systemic conditions generally emphasized the bacteriome, it is also biologically plausible, under an analogous hypothesis, that other types of organisms may have a similar role. Human viruses would be logical "suspects" in this role, given their ubiquity in the oral cavity, association with periodontal diseases, and ability to elicit strong inflammatory response, compromise immune responses, and synergize with bacteria in favor of a more pathogenic microbial consortium. In this review, the current knowledge of the role of viruses in connecting periodontal diseases and systemic conditions is examined. We will also delve into the mechanistic basis for such connections and highlight the importance of those relationships in the management and treatment of patients.

Oral Health: Opportunities for Lifestyle Medicine Highlighted by the SARS-CoV-2 Pandemic

A significant amount of illness has origins in oral microorganisms. The current SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic has reduced the general population's access to and use of routine and nonemergency dental care. This creates a dangerous situation in which oral bacteria, fungi, and viruses may remain unchecked and allowed to flourish, which in turn increases risks for several systemic diseases as well as negative outcomes for pregnancies and surgical patients. This situation presents opportunities for health maintenance and disease prevention by individuals as well as for dental health professionals to use anti-infective treatments and procedures. Lifestyle medicine professionals have a chance to encourage behaviors that individuals can undertake to promote good oral health outside of the dentist's office as well as shaping public perceptions about and reinforcing the importance of resuming dental visits as governmental restrictions allow.

Herpes simplex virus type 1 in subgingival plaque and periodontal diseases. Meta-analysis of observational studies

BACKGROUND AND OBJECTIVES

This meta-analysis of observational studies (PROSPERO registration number CRD42021236054) sought to investigate strength and generalizability of the association of herpes simplex virus type 1 (HSV-1) in subjects with plaque-induced gingivitis and periodontitis, since the data from literature are contrasting.

MATERIAL AND METHODS

Case-control and cross-sectional studies, investigating HSV-1 in subgingival plaque/crevicular fluid and periodontal status, were searched through MEDLINE via PubMed, Scopus, Web of Science and Google Scholar. From each study the crude odds ratio (OR) with 95% confidence interval (95CI) was extracted, and the pooled OR was assessed for periodontitis, chronic and aggressive, and gingivitis. The meta-analytic method was chosen based on the level of heterogeneity. The generalizability of results, determined by the meta-analysis bias, was investigated through secondary analyses including sensitivity analyses for study quality, publication bias, and study inclusion, and subgroup analyses for quality of scientific journals that published the primary studies, world Region, subgingival plaque sampling method and study design.

RESULTS

Twelve studies were included (738 cases, 551 controls). The pooled ORs were 4.4 (95CI, 1.9-10.2) for any periodontitis; specifically, 2.8 (95CI, 1.0-8.3) for chronic periodontitis, 11.8 (95CI, 5.4-25.8) for aggressive periodontitis and 4.8 (95CI, 2.1-11.0) for gingivitis. These estimates were statistically significant, excluding for chronic periodontitis, resulting marginally significant (p = .05). Secondary analyses on any and aggressive periodontitis, and, partly, chronic periodontitis corroborated the results, while the material was insufficient for secondary analyses on gingivitis.

CONCLUSIONS

The results obtained indicated that HSV-1 is associated with periodontitis, while data about gingivitis are inconclusive. HSV-1 investigation in subgingival plaque could help assess periodontitis risk and severity and, if causal association were confirmed, could contribute to its control.

Herpesviruses in Periodontitis: An Umbrella Review

BACKGROUND

Despite numerous studies indicating a high prevalence of herpesviruses in both apical and marginal periodontitis samples, their exact role in the pathogenesis of a periodontal disease is still unclear.

OBJECTIVE

This umbrella review aimed to summarize data on herpesviruses detection in marginal periodontitis (MP) and apical periodontitis of endodontic origin (APEO) samples.

METHODS

The study protocol has been drafted a priori and registered to the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42020215922). The literature search was conducted using the following electronic databases: Clarivate Analytics' Web of Science, Scopus, PubMed and Cochrane Database of Systematic Reviews, from inception to October 2020, with no language restrictions. Systematic reviews with or without meta-analysis that evaluated the association between the occurrence of herpesviruses and different forms of periodontal diseases were included. Other types of studies, including narrative reviews, were excluded. Two reviewers independently performed a literature search, data extraction, and quality assessment of included studies. Any disagreements or doubts were resolved by a third reviewer. The quality of the reviews was assessed using the AMSTAR 2 tool (A measurement tool to assess systematic reviews).

RESULTS

Six systematic reviews were included in the current review. One was graded as high quality, another one was graded as moderate quality, whereas the other four were graded as critically low-quality reviews. The presence of herpesviruses in subgingival samples was associated with an increased risk of MP, supported by the corresponding meta-analyses. Although the association was strong (OR > 3.0), the confidence intervals were wide, heterogeneity was significant, and studies were of small sample size. In addition, publication bias was detected. Contrary, data from systematic reviews that assessed APEO and herpesviruses did not show any significant associations.

CONCLUSIONS

Low-quality studies with high uncertainty suggest a strong association between herpesviruses and MP, but not with APEO.

Microbiome-mediated incapacitation of interferon lambda production in the oral mucosa

Here, we show that Porphyromonas gingivalis (Pg), an endogenous oral pathogen, dampens all aspects of interferon (IFN) signaling in a manner that is strikingly similar to IFN suppression employed by multiple viral pathogens. Pg suppressed IFN production by down-regulating several IFN regulatory factors (IRFs 1, 3, 7, and 9), proteolytically degrading STAT1 and suppressing the nuclear translocation of the ISGF3 complex, resulting in profound and systemic repression of multiple interferon-stimulated genes. Pg-induced IFN paralysis was not limited to murine models but was also observed in the oral tissues of human periodontal disease patients, where overabundance of Pg correlated with suppressed IFN generation. Mechanistically, multiple virulence factors and secreted proteases produced by Pg transcriptionally suppressed IFN promoters and also cleaved IFN receptors, making cells refractory to exogenous IFN and inducing a state of broad IFN paralysis. Thus, our data show a bacterial pathogen with equivalence to viruses in the down-regulation of host IFN signaling.

Masulili SL, Soeroso Y, Djoko Santoso W, S. Kusdhany L. Association between Epstein-Barr virus and periodontitis: A meta-analysis

Purpose

Previous studies have found that Epstein-Barr virus (EBV) is associated with periodontitis, though some controversy remains. This meta-analysis aimed to clarify and update the relationship between EBV and periodontitis as well as clinical parameters.

Methods

A comprehensive search was conducted in the PubMed and Scopus databases in December 2020. Original data were extracted according to defined inclusion and exclusion criteria. Outcomes were analyzed, including overall odds ratios (ORs) and 95% confidence intervals (CIs). A random-effects model was used, and publication bias was assessed by Egger’s and Begg’s tests. Sensitivity analysis was used to evaluate the stability of the outcome.

Results

Twenty-six studies were included in the present meta-analysis, involving 1354 periodontitis patients and 819 healthy controls. The included studies mostly showed high quality. The overall quantitative synthesis for the association between EBV and periodontitis was an increased odds ratio when subgingival EBV was detected OR = 7.069, 95% CI = 4.197–11.905, P<0.001). The results of subgroup analysis suggested that the association of EBV with periodontitis was significant in Asian, European, and American populations (P<0.001; P = 0.04; P = 0.003, respectively) but not in African populations (P = 0.29). Subgroup analysis by sample type showed that subgingival plaque (SgP), tissue and gingival crevicular fluid GCF were useful for EBV detection (P<0.001). EBV detection amplification methods included nested PCR, multiplex PCR and PCR (P<0.001; P = 0.05, P<0.001, respectively), but EBV detection by real-time PCR and loop-mediated isothermal amplification presented no significant result (P = 0.06; P = 0.3, respectively). For the clinical parameters of periodontitis, pocket depth (PD) and bleeding of probing (BOP) percentages were higher in the EBV-positive sites than in the EBV-negative sites (MD 0.47 [0.08, 0.85], P = 0.02; MD 19.45 [4.47, 34.43], P = 0.01).

Conclusions

A high frequency of EBV detection is associated with an increased risk of periodontitis. The EBV association was particularly significant in all populations except in African populations. Subgigival plaque (SgP), tissue and GCF were not significantly different useful material for detecting EBV in periodontitis. Nested PCR and multiplex PCR are reliable methods for this purpose. In the presence of EBV, PD and BOP are reliable clinical parameters for gingival inflammation. However, some caution in such interpretation is justified due to heterogeneity among studies. A suggested extension could assess the parallel influence of other human herpesviruses.

The human oral virome: Shedding light on the dark matter

Mediators of the initiation, development, and recurrence of periodontitis include the oral microbiome embedded in subgingival plaque and the host immune response to a dysbiosis within this dynamic and complex microbial community. Although mediators have been studied extensively, researchers in the field have been unable to fully ascribe certain clinical presentations of periodontitis to their nature. Emergence of high-throughput sequencing technologies has resulted in better characterization of the microbial oral dysbiosis that extends beyond the extensively studied putative bacterial periodontopathogens to a shift in the oral virome composition during disease conditions. Although the biological dark matter inserted by retroviruses was once believed to be nonfunctional, research has revealed that it encodes historical viral-eukaryotic interactions and influences host development. The objective of this review is to evaluate the proposed association of herpesviruses to the etiology and pathogenesis of periodontal disease and survey the highly abundant prokaryotic viruses to delineate their potential roles in biofilm dynamics, as well as their interactions with putative bacterial periodontopathogens and eukaryotic cells. The findings suggest that potential novel periodontal therapies targeting or utilizing the oral virome can alleviate certain clinical presentations of periodontitis. Perhaps it is time to embrace the viral dark matter within the periodontal environment to fully comprehend the pathogenesis and systemic implications of periodontitis.

Alzheimer disease and the periodontal patient: New insights, connections, and therapies

Loss of cognitive function in the aging population, particular those with Alzheimer disease, presents unique challenges to health practitioners. For the dental practitioner these include management of periodontal diseases, caries, and other dental conditions in this special population. It is well established in the cognitively impaired patient that a lack of adherence to dental hygiene routines and professional care leads to increases in the prevalence and severity of these dental conditions, leading to increased loss of teeth. More recent evidence has indicated a possible role of the microbiota of dental plaque associated with periodontal diseases in the development and progression of Alzheimer disease, thereby supporting a two-way interaction of these two diseases. New therapies are needed to address the potential upstream events that may precede overt signs of Alzheimer disease. One of these approaches would be to target these various bacterial, viral, and other microbial pathogens associated with periodontal disease that can translocate into the bloodstream and then to distal sites, such as the brain. Such microbial translocation would lead to local inflammation and buildup of the hallmark signs of Alzheimer disease, including amyloid beta deposits, tau fragmentation and tangles, breakdown of host protective molecules, such as the apolipoproteins, and neuron toxicity. In this review, evidence for the biological basis of the role of the periodontal disease microflora on the initiation and progression of Alzheimer disease will be presented with a focus on the potential role of the keystone pathogen Porphyromonas gingivalis with its family of gingipain enzymes. The various mechanisms for which P. gingivalis gingipains may contribute to the initiation and progression of Alzheimer disease are presented. Small-molecule inhibitors of these gingipains and their effects on reducing biological markers of Alzheimer disease may have beneficial effects for the initiation and progression of loss of cognitive function in Alzheimer disease. In addition to these targeted therapies for specific periodontal pathogens, considerations for the dental practitioner in applying more general approaches to reducing the periodontal plaque microflora in the management of the cognitively impaired patient are discussed for this special population.

The Role of Coinfections in the EBV-Host Broken Equilibrium

The Epstein–Barr virus (EBV) is a well-adapted human virus, and its infection is exclusive to our species, generally beginning in the childhood and then persisting throughout the life of most of the affected adults. Although this infection generally remains asymptomatic, EBV can trigger life-threatening conditions under unclear circumstances. The EBV lifecycle is characterized by interactions with other viruses or bacteria, which increases the probability of awakening its pathobiont capacity. For instance, EBV infects B cells with the potential to alter the germinal center reaction (GCR)—an adaptive immune structure wherein mutagenic-driven processes take place. HIV- and Plasmodium falciparum-induced B cell hyperactivation also feeds the GCR. These agents, along with the B cell tropic KSHV, converge in the ontogeny of germinal center (GC) or post-GC lymphomas. EBV oral transmission facilitates interactions with local bacteria and HPV, thereby increasing the risk of periodontal diseases and head and neck carcinomas. It is less clear as to how EBV is localized in the stomach, but together with Helicobacter pylori, they are known to be responsible for gastric cancer. Perhaps this mechanism is reminiscent of the local inflammation that attracts different herpesviruses and enhances graft damage and chances of rejection in transplanted patients. In this review, we discussed the existing evidence suggestive of EBV possessing the potential to synergize or cooperate with these agents to trigger or worsen the disease.

Occurrence of Candida albicans in Periodontitis

Background

Periodontal diseases are the result of an imbalance between the microbiota and immune defense. The role of yeast in the pathogenesis of these diseases has been studied. This study aims to assess the occurrence of Candida albicans in periodontitis.

Materials and Methods

Fifty subjects were recruited for the study (15 healthy individuals and 35 periodontitis subjects). The periodontal examination and plaque sampling were carried out for all patients. Candida albicans identification was based on culture, direct examination, and polymerase chain reaction. The statistical analysis was performed by SPSS 20 (SPSS Inc., Chicago, IL, USA).

Results

Twenty percent of the diseased group harbored Candida albicans which was slightly higher than in the healthy group (7%), suggesting that, under normal conditions, yeast does not grow easily in subgingival sites. However, no significant difference between the healthy and periodontitis groups (p=0.23) was found. Our results also indicated that the presence of Candida albicans was neither gender nor age related in the studied groups.

Conclusion

The results of this study suggest that Candida albicans occurs in periodontitis. More studies are needed to clarify the potential role of this yeast in different stages and forms of the disease.

Periodontal Inflammation-Triggered by Periodontal Ligament Stem Cell Pyroptosis Exacerbates Periodontitis

Periodontitis is an immune inflammatory disease that leads to progressive destruction of bone and connective tissue, accompanied by the dysfunction and even loss of periodontal ligament stem cells (PDLSCs). Pyroptosis mediated by gasdermin-D (GSDMD) participates in the pathogenesis of inflammatory diseases. However, whether pyroptosis mediates PDLSC loss, and inflammation triggered by pyroptosis is involved in the pathological progression of periodontitis remain unclear. Here, we found that PDLSCs suffered GSDMD-dependent pyroptosis to release interleukin-1β (IL-1β) during human periodontitis. Importantly, the increased IL-1β level in gingival crevicular fluid was significantly correlated with periodontitis severity. The caspase-4/GSDMD-mediated pyroptosis caused by periodontal bacteria and cytoplasmic lipopolysaccharide (LPS) dominantly contributed to PDLSC loss. By releasing IL-1β into the tissue microenvironment, pyroptotic PDLSCs inhibited osteoblastogenesis and promoted osteoclastogenesis, which exacerbated the pathological damage of periodontitis. Pharmacological inhibition of caspase-4 or IL-1β antibody blockade in a rat periodontitis model lead to the significantly reduced loss of alveolar bone and periodontal ligament damage. Furthermore, Gsdmd deficiency alleviated periodontal inflammation and bone loss in mouse experimental periodontitis. These findings indicate that GSDMD-driven PDLSC pyroptosis and loss plays a pivotal role in the pathogenesis of periodontitis by increasing IL-1β release, enhancing inflammation, and promoting osteoclastogenesis.

The human oral phageome

Oral bacteriophages (or phages), especially periodontal ones, constitute a growing area of interest, but research on oral phages is still in its infancy. Phages are bacterial viruses that may persist as intracellular parasitic deoxyribonucleic acid (DNA) or use bacterial metabolism to replicate and cause bacterial lysis. The microbiomes of saliva, oral mucosa, and dental plaque contain active phage virions, bacterial lysogens (ie, carrying dormant prophages), and bacterial strains containing short fragments of phage DNA. In excess of 2000 oral phages have been confirmed or predicted to infect species of the phyla Actinobacteria (>300 phages), Bacteroidetes (>300 phages), Firmicutes (>1000 phages), Fusobacteria (>200 phages), and Proteobacteria (>700 phages) and three additional phyla (few phages only). This article assesses the current knowledge of the diversity of the oral phage population and the mechanisms by which phages may impact the ecology of oral biofilms. The potential use of phage-based therapy to control major periodontal pathogens is also discussed.

Cytomegalovirus infection: friend or foe in rheumatoid arthritis?

Human cytomegalovirus (HCMV) is a β-herpesvirus that causes inflammation and remains for life in a latent state in their host. HCMV has been at the center of many hypotheses regarding RA.

We have recently shown that HCMV infection impairs bone erosion through the induction of the mRNA-binding protein QKI5. Latently infected RA patients display a slower progression of bone erosion in patients from a national cohort. Our observations question the possible association between HCMV and the pathophysiology of RA. In this review, we examine the possibility that HCMV may be an aggravating factor of inflammation in RA while protecting from bone erosion. We also assess its relationship with other pathogens such as bacteria causing periodontitis and responsible for ACPA production.

This review thus considers whether HCMV can be regarded as a friend or a foe in the pathogenesis and the course of RA.

Detection of Epstein-Barr Virus in Periodontitis: A Review of Methodological Approaches

Periodontitis, an inflammatory condition that affects the structures surrounding the tooth eventually leading to tooth loss, is one of the two biggest threats to oral health. Beyond oral health, it is associated with systemic diseases and even with cancer risk. Obviously, periodontitis represents a major global health problem with significant social and economic impact. Recently, a new paradigm was proposed in the etiopathogenesis of periodontitis involving a herpesviral–bacterial combination to promote long-term chronic inflammatory disease. Periodontitis as a risk factor for other systemic diseases can also be better explained based on viral–bacterial etiology. Significant efforts have brought numerous advances in revealing the links between periodontitis and Epstein–Barr virus (EBV), a gamma herpesvirus ubiquitous in the adult human population. The strong evidence from these studies may contribute to the advancement of periodontitis research and the ultimate control of the disease. Advancing the periodontitis research will require implementing suitable methods to establish EBV involvement in periodontitis. This review evaluates and summarizes the existing methods that allow the detection and diagnosis of EBV in periodontitis (also applicable in a more general way to other EBV-related diseases), and discusses the feasibility of the application of innovative emerging technologies.