Classification and diagnosis of aggressive periodontitis

Evaluation of the antibacterial activity of cinnamon essential oil and its individual compounds on Aggregatibacter actinomycetemcomitans isolated from black extrinsic tooth stain: an in vitro study

AIM

Black extrinsic tooth stain (BETS) is a health challenge that commonly affects children. Aggregatibacter actinomycetemcomitans (Aa) presents in higher prevalence within the polymicrobial community of BETS. In this study, the anti-planktonic and anti-sessile activities of cinnamon essential oil (CEO) and its individual compounds against Aa were evaluated. The preventive effect of CEO and its active substances on BETS formation was also studied in vitro.

METHODS

Aa was isolated from a preschool child with BETS and was identified based on the morphological characteristics, MALDI-TOF mass spectroscopy and 16S rRNA sequencing. The effect of CEO and its individual compounds on the growth kinetics of planktonic and sessile Aa cells as well as their antibacterial efficacy and their rate of bacterial killing were examined. The preventive effect of CEO and its active substances on the formation of BETS was evaluated using an ex vivo model. The data were analysed using one-way analysis of variance (ANOVA) and the significance level was set at p < 0.05.

RESULTS

Out of eight individual compounds of CEO, only eugenol, cinnamaldehyde and α-methyl cinnamaldehyde showed anti-Aa activities. The values of the minimum inhibitory concentrations (MICs) were in the following order: CEO (421.5 mg/ml) > α-methyl cinnamaldehyde (26.37 mg/ml) > cinnamaldehyde (0.209 mg/ml) > eugenol (0.052 mg/ml). CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde, respectively, exhibited two-, four-, four- and eightfold increase of sessile MIC compared to their planktonic MIC. The growth kinetics of both planktonic and sessile Aa in the presence of CEO, eugenol, cinnamaldehyde and α-methyl cinnamaldehyde revealed a complete inhibition at the MICs and 5.3%-37.4% biofilm inhibition at sub-MICs. The time-killing study demonstrated that CEO, eugenol and cinnamaldehyde were capable of reducing the survival rate of both planktonic and sessile Aa cells after 15-20 and 25-30 min, respectively. However, α-methyl cinnamaldehyde showed a superior anti-planktonic to anti-biofilm activity. The daily incorporation of CEO, eugenol and cinnamaldehyde at their MICs for 14 days totally prevented the formation of BETS in the ex vivo model; however, in the case of α-methyl cinnamaldehyde, BETS was visually detectable after 10 days.

CONCLUSION

CEO and its individual compounds have marked antibacterial activity against Aa. The effective results against planktonic and sessile Aa within reasonable time indicate that they can be used to prevent BETS.

Treatment of Periodontitis Affecting Human Primary Teeth-A Systematic Review

The aim of this systematic review is to report the treatment options (Intervention) and outcomes (O) for primary teeth affected by periodontitis (Population) and if the treatment of primary teeth can prevent the spread of periodontitis to permanent teeth (Outcomes). The following databases were searched for papers published before December 2022: PubMed, Embase, Web of Science, and Ebscohost. Studies on children affected by periodontitis involving the primary teeth were included and those on children who presented with periodontitis as a manifestation of systemic disease were excluded. Narrative synthesis and methodological quality assessments were performed for the included studies. Three interventional studies (without a control group) that evaluated treatments involving scaling and root planing (SRP with antibiotics) and extraction were included (total n = 60 patients). Additionally, twelve case reports/case series articles (n = 19 patients) were identified. The diagnoses ranged from aggressive periodontitis to juvenile periodontitis and pre-pubertal periodontitis. Based on a limited number of published studies, it was found that the early treatment of periodontitis affecting the primary teeth using SRP and systemic antibiotics resulted in favorable improvements in PD and CAL. Limited evidence suggests that SRP and the extraction of the primary teeth involved have the potential to prevent periodontitis affecting permanent teeth. Future trials are required to standardize the treatment protocols and to confirm these findings.

Clinical Aspects and Therapeutic Management of an Aggressive Manifestation of Stage III Grade C Periodontitis in a Female Teenager

The main objective of this study was to evaluate the improvement of periodontal health in patients with periodontitis treated with non-surgical periodontal therapy and subgingival-administrated local and systemic antimicrobial agents. A female teenager with periodontitis-associated health issues and a history of dental trauma was selected for this study. Clinical indices were obtained, and radiographic examination was performed at the beginning of the study. The patient was treated with periodontal therapy and administration of antibiotics. After this therapy, visits were scheduled at regular intervals to observe the clinical changes. Non-surgical periodontal therapy and administration of local and systemic antibiotics resulted in a reduction in the patient pocket depth probing, plaque index, and bleeding on probing. Gingival and periodontal health improved in terms of gingival overgrowth, plaque, tartar index, and tooth mobility. Suppuration was eliminated, and no gingival inflammation signs were observed.

Oral-Gut Microbiota, Periodontal Diseases, and Arthritis: Literature Overview on the Role of Probiotics

Periodontal diseases are oral inflammatory diseases affecting the tissues supporting and surrounding the teeth and include gingivitis and periodontitis. Oral pathogens may lead to microbial products spreading into the systemic circulation and reaching distant organs, while periodontal diseases have been related to low-grade systemic inflammation. Gut and oral microbiota alterations might play a role in the pathogenesis of several autoimmune and inflammatory diseases including arthritis, considering the role of the gut-joint axis in the regulation of molecular pathways involved in the pathogenesis of these conditions. In this scenario, it is hypothesized that probiotics might contribute to the oral and intestinal micro-ecological balance and could reduce low-grade inflammation typical of periodontal diseases and arthritis. This literature overview aims to summarize state-of-the-art ideas about linkages among oral-gut microbiota, periodontal diseases, and arthritis, while investigating the role of probiotics as a potential therapeutic intervention for the management of both oral diseases and musculoskeletal disorders.

CD18 Mediates Neutrophil Imperviousness to the Aggregatibacter actinomycetemcomitans JP2 Clone in Molar-Incisor Pattern Periodontitis

Introduction

Molar-incisor pattern periodontitis (MIPP) in the absence of significant local risk factors or systemic disease, is a rare, early onset periodontal disease phenotype, with 0.5% to 2.5% global prevalence. The condition is characterized by impaired neutrophil function and persistent Aggregatibacter actinomycetemcomitans (JP2 clone) infection. The aim of this study was to characterize neutrophil functional responses to JP2 and to investigate the neutrophil receptors involved.

Materials and Methods

Neutrophils were obtained from whole blood samples of periodontally healthy and MIPP subjects and incubated with the JP2 clone or a non-JP2 clone of A. actinomycetemcomitans. Bacterial survival was tested by blood agar culture; neutrophil death was tested with propidium iodide and flow cytometry; Reactive oxygen production (ROS) was measured with 2′,7′-dichlorofluorescein diacetate and a fluorescence plate reader; the cytokinome was analysed using an array profiler, ELISA and RT-PCR. Receptors binding to JP2 were isolated using a novel immunoprecipitation assay and validated functionally using specific blocking antibodies.

Results

JP2 and non-JP2 survival was comparable between all the neutrophil groups. Resistance to neutrophil necrosis following exposure to JP2 was significantly lower in the MIPP group, than in all the other groups (p<0.0001). Conversely, MIPP neutrophils showed lower levels of ROS production in response to JP2 infection compared with that of healthy neutrophils (p<0.001). Furthermore, significantly lower levels of cytokines, such as IL8, IL10 and TNFα, were observed during JP2 incubation with MIPP neutrophils than upon incubation with periodontally healthy neutrophils. Various proteins expressed on neutrophils bind to JP2. Of these, CD18 was found to mediate neutrophil necrosis. The CD18 receptor on MIPP neutrophils acts differently from that on periodontally healthy patients neutrophils, and appears to reflect differential neutrophil reactions to JP2.

Conclusion

This study portrays a fundamental difference in neutrophil response to JP2 infection between periodontally healthy and MIPP patients. This was evident in the resistance to necrosis, and lower ROS and cytokine production, despite the persistent presence of viable JP2. Whilst in periodontally healthy neutrophils, JP2 binds to CD18 on cell surfaces, this is not the case in MIPP neutrophils, suggesting a potential role for CD18 in the periodontal susceptibility of MIPP patients.

Analysis of subgingival microbiota in monozygotic twins with different severity and progression risk of periodontitis

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression.

Polymorphisms in Genes Involved in Inflammation and Periodontitis: A Narrative Review

Current evidence pinpoints that the variability in periodontitis traits in humans may be attributable to genetic factors. Different allelic variants can result in alterations in tissue structure, antibody responses and inflammatory mediators. Consequently, genetic variations may act as protective or risk factors for periodontal diseases. A number of features of the inflammatory and immune response that seem to play a role in the development of periodontitis have a clearly established genetic basis. Identifying genes that contribute to the pathogenesis of periodontitis may be utilized for risk assessment in both aggressive and chronic periodontitis. The aim of this narrative review is to summarize the role of polymorphisms in genes involved in inflammation and periodontitis, including cellular receptors, tissue compatibility antigens, antibodies and cytokines.

Photodynamic Therapy Using 5-Aminolevulinic Acid (Ala) for the Treatment of Chronic Periodontitis: A Prospective Case Series

Aim: The objective of this study was to compare the efficacy of supportive periodontal therapy (i.e., scaling and root planning, SRP) alone versus ALADENT medical device used in association with SRP in the treatment of chronic periodontitis in adult patients. Materials and Methods: A total of 20 patients with a diagnosis of chronic periodontitis (40 localized chronic periodontitis sites) aged between 35 and 55 were selected. None of these patients previously received any surgical or non-surgical periodontal therapy, and they presented radiographic evidence of moderate bone loss. Two non-adjacent sites in different quadrants were identified and observed in each patient, analyzing treatment effectiveness (split-mouth design). Clinical pocket depth, clinical attachment loss, and bleeding on probing were evaluated at time 0 and after 6 months, while microbial analysis (MA) was conducted at baseline and after 15 days. Significant differences were calculated using SPSS program and paired simple statistic t-test. Results: Total bacteria loadings had a statistically significant reduction before and after treatment with SRP (left site) (total average decrease of 27%). The sites treated with SRP plus ALADENT (right) showed a significantly reduced total bacterial loading compared to the untreated sites (right) (total average decrease of 75%). Mean values of CAL/PD and percentages data of BOP, recorded after SRP + ALADENT therapy, showed a higher reduction (CAL = 2.42, PD = 2.87 mm, 90% of sites with no bleeding) than those obtained after SRP treatment (CAL = 4.08 mm, PD = 4.73 mm, 70% of sites with no bleeding). Conclusion: The treatment of moderate and severe chronic periodontitis should include, beside SRP, the use of ALADENT medical device, which has been proved to be a useful adjuvant therapy.

Aggregatibacter actinomycetemcomitans Outer Membrane Proteins 29 and 29 Paralogue Induce Evasion of Immune Response

Aggregatibacter actinomycetemcomitans (Aa) is abundant within the microbial dysbiotic community of some patients with periodontitis. Aa outer membrane protein 29 (OMP29), a member of the OMPA family, mediates the invasion of Aa to gingival epithelial cells (GECs). This study evaluated the effect of OMP29 and its paralogue OMP29^par on the response of GECs to Aa. The omp29 or/and omp29^par deletion mutants AaΔ29, AaΔ29P, and AaΔ29Δ29P were constructed, and recombinant Aa OMP29^His was obtained. Microarray analysis and the evaluation of cxcl-8 gene expression were performed to examine the response of GECs line OBA-09 to Aa and its mutants. The expression of cxcl-8 and its product CXCL-8 was examined in LPS-stimulated OBA-09 cells with Aa OMP29^His. Proteomics analysis showed that the deletion of omp29 led to overexpression of both OMP29^par and another membrane protein OMP39, the expression of which was further increased in AaΔ29Δ29P. OBA-09 cells challenged with AaΔ29Δ29P exhibited a higher expression of cxcl-8 in comparison to wildtype Aa strain AaD7S or single-deletion mutants AaΔ29 or AaΔ29P. LPS-stimulated OBA-09 cells challenged with Aa OMP29^His showed reduced expressions of cxcl-8 and its product CXCL-8. OBA-09 cells challenged with AaΔ29Δ29P in comparison to Aa strain AaD7S resulted in higher expressions of genes involved in apoptosis and inflammatory response such as bcl2, birc3, casp3, c3, ep300, fas, fosb, grb2, il-1α, il-1β, il-6, cxcl-8, nr3c1, prkcq, socs3, and tnfrsf1β and reduced expressions of cd74, crp, faslg, tlr1, and vcam1. The results suggested a novel strategy of Aa, mediated by OMP29 and OMP29^par, to evade host immune response by inhibiting CXCL-8 expression and modulating the genes involved in apoptosis and inflammatory response in GECs. Pending further confirmation, the strategy might interfere with the recruitment of neutrophils and dampen the host inflammatory response, leading to a more permissive subgingival niche for bacterial growth.

Identifying periodontitis risk factors through a retrospective analysis of 80 cases

Objectives:

To investigate periodontitis risk factors and to establish a reference framework for identifying factors that place individuals at greater risk for periodontitis.

Methods:

Clinical data from 80 periodontitis patients admitted in the Department of Stomatology at Hebei Provincial People’s Hospital and treated between March 2020 and March 2021 were retrospectively analyzed.

Results:

Univariate analysis showed that lower daily brushing frequencies, decreased tooth brushing duration, decreased scaling frequency, dietary habits, smoking and drinking, genetic factors, diabetes, hypertension, and obesity were more prevalent among periodontitis patients than healthy controls. Multivariate binary logistic analysis showed that daily brushing frequency, routine scaling, smoking, drinking, heredity, diabetes, hypertension, and obesity were all risk factors for periodontitis.

Conclusions:

There are many risk factors for periodontitis. Clinicians need to be aware of these factors for early detection and treatment of the disease.

Azithromycin as an adjunct to subgingival professional mechanical plaque removal in the treatment of grade C periodontitis: a systematic review and meta-analysis

The aim of this systematic review was to evaluate clinical and microbiological outcomes with the use of azithromycin as an adjunct to non-surgical subgingival professional mechanical plaque removal (PMPR) in the treatment of grade C periodontitis. Online database searches using high-level MeSH terms in a PICO structure were conducted along with hand-searching of relevant periodontal journals. Titles and abstracts of identified studies were independently reviewed by both authors and the full texts of studies meeting the inclusion criteria were independently reviewed. In total, 122 studies were identified through searches, of which 6 were included in the qualitative analysis and 4 in the meta-analysis. Three studies included in the meta-analysis were deemed at low risk of bias and 1 at serious risk. There were conflicting results on whether azithromycin reduced the number of subgingival pathogens or detectable subgingival Aggregatibacter actinomycetemcomitans between the included studies. The meta-analysis revealed a statistically significant probing depth reduction difference in favour of azithromycin compared to the control at 3 months (weighted mean difference [WMD]=−0.39 mm; 95% confidence interval [CI], −0.66 to −0.13 mm; I²=0%) and 12 months (WMD=−1.32 mm; 95% CI, −1.71 to −0.93 mm; I²=0%). The clinical attachment level change was also statistically significant in favour of azithromycin compared to the control at 3 months (WMD=−0.61 mm; 95% CI, −1.13 to −0.10 mm; I²=71%) and 12 months (WMD=−0.88 mm; 95% CI, −1.32 to −0.44 mm; I²=0%). Based upon these results, azithromycin offers additional improvements in some clinical parameters when used in conjunction with subgingival PMPR in patients with aggressive periodontitis over control groups. These improvements appear to be maintained for up to 12 months after treatment completion. However, due to a lack of well-designed studies, the conclusions that can be drawn from the available evidence are limited.

Friends with Benefits: An Inside Look of Periodontal Microbes' Interactions Using Fluorescence In Situ Hybridization-Scoping Review

Fluorescence in situ hybridization (FISH) has proven to be particularly useful to describe the microbial composition and spatial organization of mixed microbial infections, as it happens in periodontitis. This scoping review aims to identify and map all the documented interactions between microbes in periodontal pockets by the FISH technique. Three electronic sources of evidence were consulted in search of suitable articles up to 7 November 2020: MEDLINE (via PubMed), Scopus (Elsevier: Amsterdam, The Netherlands), and Web of Science (Clarivate Analytics: Philadelphia, PA, USA) online databases. Studies that showed ex vivo and in situ interactions between, at least, two microorganisms were found eligible. Ten papers were included. Layered or radially ordered multiple-taxon structures are the most common form of consortium. Strict or facultative anaerobic microorganisms are mostly found in the interior and the deepest portions of the structures, while aerobic microorganisms are mostly found on the periphery. We present a model of the microbial spatial organization in sub- and supragingival biofilms, as well as how the documented interactions can shape the biofilm formation. Despite the already acquired knowledge, available evidence regarding the structural composition and interactions of microorganisms within dental biofilms is incomplete and large-scale studies are needed.

Anna Karenina and the subgingival microbiome associated with periodontitis

BACKGROUND

Although localized aggressive periodontitis (LAP), generalized aggressive periodontitis (GAP), and chronic periodontitis (CP) are microbially driven diseases, our inability to separate disease-specific associations from those common to all three forms of periodontitis has hampered biomarker discovery. Therefore, we aimed to map the genomic content of, and the biological pathways encoded by, the microbiomes associated with these clinical phenotypes. We also estimated the extent to which these biomes are governed by the Anna Karenina principle (AKP), which states that eubiotic communities are similar between individuals while disease-associated communities are highly individualized.

METHODS

We collected subgingival plaque from 25 periodontally healthy individuals and diseased sites of 59 subjects with stage 3 periodontitis and used shotgun metagenomics to characterize the aggregate of bacterial genes.

RESULTS

Beta-dispersion metrics demonstrated that AKP was most evident in CP, followed by GAP and LAP. We discovered broad dysbiotic signatures spanning the three phenotypes, with over-representation of pathways that facilitate life in an oxygen-poor, protein- and heme-rich, pro-oxidant environment and enhance capacity for attachment and biofilm formation. Phenotype-specific indicators were more readily evident in LAP microbiome than GAP or CP. Genes that enable acetate-scavenging lifestyle, utilization of alternative nutritional sources, oxidative and nitrosative stress responses, and siderophore production were unique to LAP. An attenuation of virulence-related functionalities and stress response from LAP to GAP to CP was apparent. We also discovered that clinical phenotypes of disease resolved variance in the microbiome with greater clarity than the newly established grading system. Importantly, we observed that one third of the metagenome of LAP is unique to this phenotype while GAP shares significant functional and taxonomic features with both LAP and CP, suggesting either attenuation of an aggressive disease or an early-onset chronic disease.

CONCLUSION

Within the limitations of a small sample size and a cross-sectional study design, the distinctive features of the microbiomes associated with LAP and CP strongly persuade us that these are discrete disease entities, while calling into question whether GAP is a separate disease, or an artifact induced by cross-sectional study designs. Further studies on phenotype-specific microbial genes are warranted to explicate their role in disease etiology. Video Abstract.

Inflammatory Status and Glycemic Control Level of Patients with Type 2 Diabetes and Periodontitis: A Randomized Clinical Trial

Background: Based on the holistic approach to prevention diabetic disease, the role of periodontal inflammation in type 2 diabetes mellitus (T2DM) is under intensive scrutiny. Data from clinical trials have shown benefit from a periodontal therapy in providing patients with type 2 diabetes improvement despite relatively disappointing long-terms response rates. The aim of this study was to investigate the short-term glycemic control level and systemic inflammatory status after periodontal therapy. Methods: This was a randomized trial with a 6-months follow-up. Participants aged 56.4 ± 7.9 years with diagnosed type 2 diabetes and periodontitis were enrolled. Among the 187 type 2 diabetic patients, 93 were randomly assigned to receive non-surgical periodontal treatment immediately and 94 to receive the delayed treatment. Within and between groups comparison was done during the study period, and the differences between groups were assessed. Results: The difference between HbA1c values at baseline (Mdn = 7.7) and 6 months after non-surgical periodontal treatment (Mdn = 7.2) was statistically significant, U = 3174.5, p = 0.012, r = 0.187. However, although technically a positive correlation, the relationship between the glycated hemoglobin value and periodontal variables was weak. The differences between both the groups over 6 months were not statistically considerable, failing to reach statistical significance. At 6 months the difference between groups about the C-reactive protein (CRP) levels was statistically significant, U=1839.5, p = 0, r = 0.472, with a lower concentration for the intervention group. Furthermore, the intervention group showed a statistically significant difference between baseline and 6 months evaluation (U = 2606.5, p = 0, r = 0.308). Conclusions: The periodontal intervention potentially may allow individuals with type 2 diabetes to improve glycemic control and CRP concentrations, and diabetes alters the periodontal status.

Reliability of microarray analysis for studying periodontitis: low consistency in 2 periodontitis cohort data sets from different platforms and an integrative meta-analysis

PURPOSE

The aim of this study was to compare the characteristic expression patterns of advanced periodontitis in 2 cohort data sets analyzed using different microarray platforms, and to identify differentially expressed genes (DEGs) through a meta-analysis of both data sets.

METHODS

Twenty-two patients for cohort 1 and 40 patients for cohort 2 were recruited with the same inclusion criteria. The 2 cohort groups were analyzed using different platforms: Illumina and Agilent. A meta-analysis was performed to increase reliability by removing statistical differences between platforms. An integrative meta-analysis based on an empirical Bayesian methodology (ComBat) was conducted. DEGs for the integrated data sets were identified using the limma package to adjust for age, sex, and platform and compared with the results for cohorts 1 and 2. Clustering and pathway analyses were also performed.

RESULTS

This study detected 557 and 246 DEGs in cohorts 1 and 2, respectively, with 146 and 42 significantly enriched gene ontology (GO) terms. Overlapping between cohorts 1 and 2 was present in 59 DEGs and 18 GO terms. However, only 6 genes from the top 30 enriched DEGs overlapped, and there were no overlapping GO terms in the top 30 enriched pathways. The integrative meta-analysis detected 34 DEGs, of which 10 overlapped in all the integrated data sets of cohorts 1 and 2.

CONCLUSIONS

The characteristic expression pattern differed between periodontitis and the healthy periodontium, but the consistency between the data sets from different cohorts and metadata was too low to suggest specific biomarkers for identifying periodontitis.

A 2-plane micro-computed tomographic alveolar bone measurement approach in mice

Purpose

This study introduces a standardized 2-plane approach using 8 landmarks to assess alveolar bone levels in mice using micro-computed tomography.

Materials and Methods

Bone level differences were described as distance from the cemento-enamel junction (CEJ) to alveolar bone crest (ABC) and as percentages of vertical bone height and vertical bone loss, comparing mice infected with Porphyromonas gingivalis (Pg) to controls. Eight measurements were obtained per tooth: 2 in the sagittal plane (mesial and distal) and 6 in the coronal plane (mesiobuccal, middle-buccal, distobuccal, mesiolingual, middle-lingual, and distolingual).

Results

Significant differences in the CEJ-to-ABC distance between Pg-infected mice and controls were found in the coronal plane (middle-lingual, mesiobuccal, and distolingual for the first molar; and mesiobuccal, middle-buccal, and distolingual for the second molar). In the sagittal plane, the distal measurement of the second molar was different. The middle-buccal, mesiobuccal, and distolingual sites of the first and second molars showed vertical bone loss relative to controls; the second molar middle-lingual site was also different. In the sagittal plane, the mesial sites of the first and second molars and the distal site of the second molar showed loss. Significantly different vertical bone height percentages were found for the mesial and distal sites of the second molar (sagittal plane) and the middle-lingual and distolingual sites of the first molar(coronal plane).

Conclusion

A reliable, standardized technique for linear periodontal assessments in mice is described. Alveolar bone loss occurred mostly on the lingual surface of the coronal plane, which is often omitted in studies.

NETs Are Double-Edged Swords with the Potential to Aggravate or Resolve Periodontal Inflammation

Periodontitis is a general term for diseases characterised by inflammatory destruction of tooth-supporting tissues, gradual destruction of the marginal periodontal ligament and resorption of alveolar bone. Early-onset periodontitis is due to disturbed neutrophil extracellular trap (NET) formation and clearance. Indeed, mutations that inactivate the cysteine proteases cathepsin C result in the massive periodontal damage seen in patients with deficient NET formation. In contrast, exaggerated NET formation due to polymorphonuclear neutrophil (PMN) hyper-responsiveness drives the pathology of late-onset periodontitis by damaging and ulcerating the gingival epithelium and retarding epithelial healing. Despite the gingival regeneration, periodontitis progression ends with almost complete loss of the periodontal ligament and subsequent tooth loss. Thus, NETs help to maintain periodontal health, and their dysregulation, either insufficiency or surplus, causes heavy periodontal pathology and edentulism.

Microbiomics: Were we all wrong before?

Periodontal microbiology has historically been based on an "us against them" paradigm, one that focuses mainly on identifying microbes and viruses that cause disease. However, such a bottom-up approach limits our appreciation of the incredible diversity of this ecosystem and the essential ways in which microbial interactions contribute to health and homeostasis of the subgingival niche. Microbiomics-the science of collectively characterizing and quantifying molecules responsible for the structure, function, and dynamics of a microbial community-has enabled us to study these communities in their natural habitat, thereby revolutionizing our knowledge of host-associated microbes and reconceptualizing our definition of "human." When this systems-biology approach is combined with ecologic principles, it explicates the complex relationship that exist between microbiota and between them and us, the human. In this volume of Periodontology 2000, a group of 12 female scientists take the lead in investigating how metagenomics, genomics, metatranscriptomics, proteomics, metaproteomics, and metabolomics have achieved the following: (a) widened our view of the periodontal microbiome; (b) expanded our understanding of the evolution of the human oral microbiome; (c) shone a light on not just bacteria, but also other prokaryotic and eukaryotic members of the community; (d) elucidated the effects of anthropogenic behavior and systemic diseases on shaping these communities; and (e) influenced traditional patterns of periodontal therapeutics.

The Association Between Oral Hygiene Behavior and Gingival Health Status with the Stage and Grade of Periodontitis: A Cross-Sectional Study

Aim:

To analyze the association between teeth brushing (TB) and interdental cleansing (IDC) frequency changes with gingival health status and the stage and grade of periodontitis.

Materials and Methods:

This cross-sectional study consisted of clinical examination and questionnaires. The questionnaires include demographic information and oral hygiene (TB and IDC) behavior. More than 18-year-old participants who underwent a periodontal treatment were randomly included. 548 individuals were classified as gingival healthy, gingivitis, and periodontitis according to the 2017 classification system. The degree of periodontitis was based on stage and grade systems. The data were analyzed by using Kruskal–Wallis and Mann–Whitney U tests.

Results:

The highest TB frequency (twice daily) was the highest in patients with gingivitis (83.7%) followed by healthy patients (82.9%) and patients with stage I periodontitis (52.2%). Compared to those who performed IDC daily, 18.9% of patients were healthy and 8.1% had stage II periodontitis. There was a statistically significant association between the oral hygiene behavior and periodontal health status of participants. Statistically significant association was seen between the TB and IDC with stage-grade of periodontitis. When the TB and IDC scores of different grade groups were compared at the same stage level, no statistically significant difference was found.

Conclusion:

This study showed that periodontal health status was positively correlated with TB and IDC frequency.

The Dental, Oral, Medical Epidemiological (DOME) Study: Protocol and Study Methods

OBJECTIVES

To develop and present the methods utilized for the Dental, Oral, Medical Epidemiological (DOME) study.

METHODS

The DOME is an electronic record-based cross-sectional study, that was conducted to measure the dental, periodontal, and oral morbidities and their associations with systemic morbidities, among a nationally representative sample of young to middle-aged adults military personnel from the IDF (Israel Defense Forces). To that end, we developed a strict protocol including standardized terminology, data collection, and handling.

RESULTS

Data for the DOME study was derived simultaneously from three electronic records of the IDF: (1) a central demographic database, (2) the dental patient record (DPR), and (3) the medical computerized patient record (CPR). The established DOME repository includes socio-demographic, dental and medical records of 132,354 young to middle-age military personnel from the IDF, who attended the dental clinics during the year 2015. Records of general military personnel (N > 50,000), with no recorded dental visits during the study period, served as a control group regarding all other parameters except dental. The DOME study continues and is currently collecting longitudinal data from the year 2010 until 2020. The IDF employs a standardized uniform administrative and clinical work-up and treatment protocols as well as uniform computerized codes. We describe the standardized definitions for all the parameters that were included: socio-demographics, health-related habits, medical and dental attendance patterns, and general and dental health status. Multicollinearity analysis results of the sociodemographic and medical study parameters are presented.

CONCLUSION

Standardized work-up and definitions are essential to establish the centralized DOME data repository to study the extent of dental and systemic morbidities and their associations.

Impact of Notch signalling molecules and bone resorption regulators on clinical parameters in periodontitis

BACKGROUND AND OBJECTIVE

Notch signalling cascade has recently been connected to alveolar bone resorption in periodontitis. Hence, the present cross-sectional study aimed to analyze the expression of Notch signalling pathway (Notch 1, Notch 2, Jagged 1, Hes 1, Hey 1) and periodontitis-related (tumor necrosis factor alpha- TNF-α, interleukin 17-IL-17, receptor activator of nuclear factor-kappa B ligand-RANKL, osteoprotegerin-OPG) molecules and correlate it with clinical parameters in aggressive (AP) and chronic (CP) periodontitis. Additionally, the aforementioned markers' expression was evaluated in periodontitis patients with different RANKL/OPG ratios.

MATERIAL AND METHODS

Eighty patients were enrolled either in AP or CP group. Clinical attachment level (CAL), bleeding on probing (BOP), periodontal probing depth (PPD) and plaque index (PI) were recorded for each patient. Total RNA was extracted from gingival crevicular fluid samples. Relative gene expression of investigated markers was determined by reverse transcriptase-real-time polymerase chain reaction.

RESULTS

Significantly higher values of PPD were observed in AP compared to CP (P = .010). Negative correlations between OPG and CAL, and OPG and PI, were found in AP (P = .045, P = .006, respectively), while Hey 1 and PI had a positive correlation (P = .049). In multivariate linear regression analysis, OPG and Notch 2 were predictors of CAL in AP group. TNF-α and IL-17 were higher in RANKL predominant than in OPG predominant cases (P = .007, P = .001, respectively). In RANKL predominant lesions Notch 1 and Jagged 1 were down-regulated in AP compared to CP patients (P = .010, P = .025, respectively).

CONCLUSION

The present study demonstrated that changes in Notch 2 expression affected CAL in AP cases hence this molecule could be considered as a contributor to alveolar bone loss. In RANKL-activated settings, the down-regulation of Notch 1 might participate in more severe bone resorption in AP.

The role of inflammation and genetics in periodontal disease

Periodontitis is a complex disease: (a) various causative factors play a role simultaneously and interact with each other; and (b) the disease is episodic in nature, and bursts of disease activity can be recognized, ie, the disease develops and cycles in a nonlinear fashion. We recognize that various causative factors determine the immune blueprint and, consequently, the immune fitness of a subject. Normally, the host lives in a state of homeostasis or symbiosis with the oral microbiome; however, disturbances in homeostatic balance can occur, because of an aberrant host response (inherited and/or acquired during life). This imbalance results from hyper- or hyporesponsiveness and/or lack of sufficient resolution of inflammation, which in turn is responsible for much of the disease destruction seen in periodontitis. The control of this destruction by anti-inflammatory processes and proresolution processes limits the destruction to the tissues surrounding the teeth. The local inflammatory processes can also become systemic, which in turn affect organs such as the heart. Gingival inflammation also elicits changes in the ecology of the subgingival environment providing optimal conditions for the outgrowth of gram-negative, anaerobic species, which become pathobionts and can propagate periodontal inflammation and can further negatively impact immune fitness. The factors that determine immune fitness are often the same factors that determine the response to the resident biofilm, and are clustered as follows: (a) genetic and epigenetic factors; (b) lifestyle factors, such as smoking, diet, and psychosocial conditions; (c) comorbidities, such as diabetes; and (d) local and dental factors, as well as randomly determined factors (stochasticity). Of critical importance are the pathobionts in a dysbiotic biofilm that drive the viscious cycle. Focusing on genetic factors, currently variants in at least 65 genes have been suggested as being associated with periodontitis based on genome-wide association studies and candidate gene case control studies. These studies have found pleiotropy between periodontitis and cardiovascular diseases. Most of these studies point to potential pathways in the pathogenesis of periodontal disease. Also, most contribute to a small portion of the total risk profile of periodontitis, often limited to specific racial and ethnic groups. To date, 4 genetic loci are shared between atherosclerotic cardiovascular diseases and periodontitis, ie, CDKN2B-AS1(ANRIL), a conserved noncoding element within CAMTA1 upstream of VAMP3, PLG, and a haplotype block at the VAMP8 locus. The shared genes suggest that periodontitis is not causally related to atherosclerotic diseases, but rather both conditions are sequelae of similar (the same?) aberrant inflammatory pathways. In addition to variations in genomic sequences, epigenetic modifications of DNA can affect the genetic blueprint of the host responses. This emerging field will yield new valuable information about susceptibility to periodontitis and subsequent persisting inflammatory reactions in periodontitis. Further studies are required to verify and expand our knowledge base before final cause and effect conclusions about the role of inflammation and genetic factors in periodontitis can be made.

Interleukin Gene Variability and Periodontal Bacteria in Patients with Generalized Aggressive Form of Periodontitis

Host genetic predispositions to dysregulated immune response can influence the development of the aggressive form of periodontitis (AgP) through susceptibility to oral dysbiosis and subsequent host-microbe interaction. This case-control study aimed to perform a multilocus analysis of functional variants in selected interleukin (IL) genes in patients with the generalized form of AgP in a homogenous population. Twelve polymorphisms in IL-1 gene cluster, IL-6 and its receptor, IL-10, IL-17A, and IL-18 were determined in 91 AgP patients and 210 controls. Analysis of seven selected periodontal bacteria in subgingival sulci/pockets was performed with a commercial DNA-microarray kit in a subgroup of 76 individuals. The pilot in vitro study included stimulation of peripheral blood monocytes (PBMC) from 20 individuals with periodontal bacteria and measurement of IL-10 levels using the Luminex method. Only the unctional polymorphism IL-10 −1087 A/G (rs1800896) and specific IL-10 haplotypes were associated with the development of the disease (p < 0.05, P_corr > 0.05). Four bacterial species occurred more frequently in AgP than in controls (p < 0.01, P_corr < 0.05). Elevated IL-10 levels were found in AgP patients, carriers of IL-10 −1087GG genotype, and PBMCs stimulated by periodontal bacteria (p < 0.05, P_corr > 0.05). We therefore conclude that a combination of genetic predisposition to the altered expression of IL-10 and the presence of specific periodontal bacteria may contribute to Th1/Th2 balance disruption and AgP development.

Global prevalence of aggressive periodontitis: A systematic review and meta-analysis

AIM

The prevalence of aggressive periodontitis (AgP) varies considerably between studies. The aim of this meta-analysis was to estimate, throughout the world, the prevalence of this disease.

MATERIALS AND METHODS

Pubmed/Medline, Scopus, Science Direct, EBSCO and Cochrane library were systematically searched up to March 2018. Study selection criteria included cross-sectional studies reporting prevalence of AgP in non-specific population and permanent dentition. We assessed risk of bias using the Joanna Briggs Institute tool. A random effect meta-analysis model was used to estimate the prevalence of AgP. Publication bias was assessed by Begg and Egger's tests and visual aspect of funnel plot.

RESULTS

A total of 33 articles were included. Pooled prevalence for AgP was 1.6% (95% CI 1.1-2.3). Higher pooled prevalence rates were reported in Africa (4.2%, 95% CI 2.0-7.1) and South America (4.0%, 95% CI 0.9-9.1) compared with Europe (0.1%, 95% CI 0.1-0.2). A pooled prevalence of 1.2%, 95% CI 0.5-2.2 was found in Asia and 0.8%, 95% CI 0.4-1.4 in North America. Heterogeneity between groups was statistically significant (Q statistic p < .001).

CONCLUSIONS

A relatively high prevalence of AgP was found in Africa. However, the data support the weakness of the definition of this form of periodontal disease. Studies with less heterogeneity are needed to address accurately the prevalence of AgP.

Analysis of curtailing prevalence estimates of periodontitis post the new classification scheme: A cross-sectional study

Aim:

Among various dental ailments, periodontitis has always had a towering popularity. The inauguration of new classification scheme for periodontal diseases and conditions in 2017 World Workshop has a remarkable impact on the diagnosis of periodontal diseases worldwide. This study is based on comparison between the two classifications by American Academy of Periodontology for diagnosing periodontitis.

Materials and Methods:

This study focuses on the prevalence estimates of periodontitis by diagnosing the periodontal diseases using two different criteria simultaneously: the first criterion was based on the classification approved in 1999 World Workshop and the other criterion was based on the new classification scheme of periodontal diseases and conditions in 2017 World Workshop.

Results:

It was found that there was significant reduction in the prevalence estimates (P < 0.001) of periodontitis following the new classification scheme.

Conclusion:

The new classification scheme recognizes the clinical salience of periodontitis and is more likely to influence the treatment modality of long sufferings of the patients having periodontal problems across the globe. The new classification will also lay the base for future research in the field of dentistry. More future studies are required to assess the prevalence of periodontitis following new classification scheme on a larger scale.

Repeated application of photodynamic and antibiotic therapy as an adjunct to root surface debridement in patients with grade C and stage III or IV aggressive periodontitis

PURPOSE

To evaluate the efficacy of antimicrobial photodynamic therapy (aPDT) and antimicrobial therapy on clinical and immunological outcomes of periodontal treatment in patients with periodontitis grade C and stage III or IV.

MATERIAL AND METHOD

The patients recruited in the current research fulfil the clinical case definition of periodontitis 'grade C' in terms of onset of the infection and stage III or IV that defines degree and severity of the disease. One-stage full-mouth ultrasonic debridement (UD) was performed and randomly divided in two groups: Group-I - four applications of aPDT, and Group-II - combination of metronidazole (MTZ) and amoxicillin (AMX) 3 tablets each for 7 days. Whole-mouth periodontal parameters were recorded at baseline, 3-, 6-months after completion of treatment. Gingival crevicular fluid samples were obtained for assessment of inflammatory interleukin (IL)-10 and IL-17 at the same time points.

RESULTS

Seventeen healthy patients completed the study protocol and revealed similar clinical findings at baseline. Bleeding scores significantly reduced in group-I at 3 months post treatment (p < 0.05). It could be seen that group-I showed statistically significant reduction of deep periodontal pockets and gain in CAL in patients with GAP at 3 months (p < 0.05). This difference was maintained at 6 months of follow-up (p < 0.001). Group-II was capable of increasing the levels of IL-10 and reducing IL-17 in GCF at both time periods compared to Group-I (p < 0.05). Group-I did not have significant effect on either cytokine levels in GCF (p > 0.05).

CONCLUSION

Antimicrobial photodynamic therapy improved severe deep periodontal pockets. However, the combination of antimicrobial therapy helped in reducing proinflammation in grade C and stage III or IV periodontitis.

Hidden noise in immunologic parameters might explain rapid progression in early-onset periodontitis

To investigate in datasets of immunologic parameters from early-onset and late-onset periodontitis patients (EOP and LOP), the existence of hidden random fluctuations (anomalies or noise), which may be the source for increased frequencies and longer periods of exacerbation, resulting in rapid progression in EOP. Principal component analysis (PCA) was applied on a dataset of 28 immunologic parameters and serum IgG titers against periodontal pathogens derived from 68 EOP and 43 LOP patients. After excluding the PCA parameters that explain the majority of variance in the datasets, i.e. the overall aberrant immune function, the remaining parameters of the residual subspace were analyzed by computing their sample entropy to detect possible anomalies. The performance of entropy anomaly detection was tested by using unsupervised clustering based on a log-likelihood distance yielding parameters with anomalies. An aggregate local outlier factor score (LOF) was used for a supervised classification of EOP and LOP. Entropy values on data for neutrophil chemotaxis, CD4, CD8, CD20 counts and serum IgG titer against Aggregatibacter actinomycetemcomitans indicated the existence of possible anomalies. Unsupervised clustering confirmed that the above parameters are possible sources of anomalies. LOF presented 94% sensitivity and 83% specificity in identifying EOP (87% sensitivity and 83% specificity in 10-fold cross-validation). Any generalization of the result should be performed with caution due to a relatively high false positive rate (17%). Random fluctuations in immunologic parameters from a sample of EOP and LOP patients were detected, suggesting that their existence may cause more frequently periods of disease activity, where the aberrant immune response in EOP patients result in the phenotype "rapid progression".

Periodontitis: Consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions

A new periodontitis classification scheme has been adopted, in which forms of the disease previously recognized as "chronic" or "aggressive" are now grouped under a single category ("periodontitis") and are further characterized based on a multi-dimensional staging and grading system. Staging is largely dependent upon the severity of disease at presentation as well as on the complexity of disease management, while grading provides supplemental information about biological features of the disease including a history-based analysis of the rate of periodontitis progression; assessment of the risk for further progression; analysis of possible poor outcomes of treatment; and assessment of the risk that the disease or its treatment may negatively affect the general health of the patient. Necrotizing periodontal diseases, whose characteristic clinical phenotype includes typical features (papilla necrosis, bleeding, and pain) and are associated with host immune response impairments, remain a distinct periodontitis category. Endodontic-periodontal lesions, defined by a pathological communication between the pulpal and periodontal tissues at a given tooth, occur in either an acute or a chronic form, and are classified according to signs and symptoms that have direct impact on their prognosis and treatment. Periodontal abscesses are defined as acute lesions characterized by localized accumulation of pus within the gingival wall of the periodontal pocket/sulcus, rapid tissue destruction and are associated with risk for systemic dissemination.

Associations of P2RX7 Functional Diplotypes with Localized Aggressive Periodontitis

AIM

The purpose of this study was to test for the role of the P2X7 receptor in localized aggressive periodontitis (LAP).

METHODS

Peripheral blood was obtained from 95 subjects with LAP and 76 healthy unrelated controls (HUCs). Three P2RX7 single-nucleotide polymorphisms (rs1718119, rs2230911, and rs3751143) were genotyped from these subjects, and their peripheral blood samples were stimulated with lipopolysaccharide (LPS) from Escherichia coli and tested for inflammatory markers. The 3 P2RX7 single-nucleotide polymorphisms were in found to be in perfect linkage disequilibrium, and a total of 4 haplotypes and 9 diplotypes were identified among all subjects. For both subject populations, the 9 diplotypes were grouped into 4 functional groups and tested for association with subject inflammatory response. To specifically study the effects of extrinsic activation of the P2X7 receptor in LAP, peripheral blood samples from were stimulated under 3 treatments: LPS, LPS + ATP, and LPS +ATP+ P2X7 selective inhibitor. The effects of these treatments on P2X7 receptor activity were measured through Luminex protein assay. Last, to test whether receptor stimulation was related to P2RX7 expression, relative mRNA levels of P2RX7 were quantified with real-time quantitative polymerase chain reaction.

RESULTS

Several associations between the P2RX7 diplotypes and LPS-stimulated blood chemokine/cytokine levels were found between the LAP and HUC populations (P < 0.05). P2X7 activation resulted in statistically significant differences in IL-1β and IL-12p40 concentrations for both subject populations. The relative P2RX7 mRNA levels increased significantly after addition of its inhibitor for both LAP and HUC populations.

CONCLUSIONS

This study detected an association between P2RX7 functional diplotypes and in vitro immune response of whole blood from subjects with LAP. In addition, we found that inhibition of the activated P2X7 receptor leads to increased P2RX7 mRNA levels, suggesting a feedback loop ( ClinicalTrials.gov NCT01330719).

KNOWLEDGE TRANSFER STATEMENT

The results of this study suggest that P2RX7 functional diplotypes are associated with LAP and their in vitro immune response to bacteria. Ongoing studies to uncover the mechanistic link between P2RX7 and LAP phenotypes could lead to the development of preventive approaches for susceptible subjects.

Treatment of intrabony defects with modified perforated membranes in aggressive periodontitis: a 4-year follow-up of a randomized controlled trial

OBJECTIVE

(1) To assess long-term outcomes 4 years following guided tissue regeneration (GTR) of intrabony defects in patients diagnosed with aggressive periodontitis (AgP) and (2) to identify predictors of clinical attachment level (CAL) gain and bone/graft density gain.

MATERIALS AND METHODS

In 15 patients, two deep intrabony defects were randomly treated with xenogenic graft plus modified perforated membranes (MPM, tests) or xenogenic graft plus standard collagen membranes (CM, controls). After 4 years, clinical and radiographic outcomes were evaluated and compared with outcomes at baseline and after 1 year.

RESULTS

After 4 years, 14 test sites and 13 control sites were available for analysis. One tooth was lost as a result of root fracture. There were significant improvements in all evaluated parameters after 1 and 4 years in relation to baseline, but no differences were observed between tests and controls. However, some non-significant changes were found between 1 and 4 years. Regression analyses showed that recurrence of periodontitis was a significant predictor for CAL gain (p = 0.001) and bone/graft density gain (p = 0.024) from 1 to 4 years.

CONCLUSIONS

GTR of intrabony defects in AgP with either standard or modified CM yielded similarly successful and maintainable clinical benefits for compromised teeth 4 years following the surgery. The use of MPM showed no additional benefit.

CLINICAL RELEVANCE

This study demonstrates that most of the positive outcomes of GTR in AgP may be preserved over 4 years. Periodontitis recurrence might influence long-term outcomes.

Clinical and radiographic peri-implant outcomes of short dental implants placed in posterior jaws of patients with treated generalized aggressive periodontitis: A 3-year follow-up study

BACKGROUND

Studies assessing clinical and radiographic peri-implant parameters around short dental implants (SDIs) in treated generalized aggressive periodontitis (GAgP) patients are scant.

OBJECTIVES

This 3-year follow-up study aimed to compare the clinical peri-implant and radiographic bone status around SDIs placed in partially edentulous patients treated for GAgP and periodontally healthy patients and to assess the implant success rate between both the groups.

MATERIALS AND METHODS

A total of seven patients clinically diagnosed with GAgP and seven periodontally healthy patients was included in the clinical study. Forty-eight (29 maxilla; 19 mandible) and 11 (8 maxilla; 3 mandible) SDIs were placed in the GAgP group and healthy group, respectively. Plaque index (PI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL) were recorded at six sites around all teeth and implants. Marginal bone loss (MBL) was studied incorporating in a specialized software and examined on a calibrated computer display screen with the help of an image analyzer. Patient satisfaction was recorded using a questionnaire sheet that contained questions regarding esthetics and function of the restorations.

RESULTS

The implant survival rate after 3 years was 81.25%. BOP and CAL around SDIs of GAgP patients were significantly higher than in periodontally healthy subjects (P = .01) throughout the follow-up. CAL around the teeth of GAgP patients was significantly greater during the follow-up than around the teeth of periodontal healthy subjects (P = .02). The PI and BOP between the teeth and implants showed no statistical significant difference. The mean PD at teeth was 0.4 mm greater than at implants. Implants showed significantly increased attachment loss than teeth (P = .01). The overall mean satisfaction of visual analogue scale was 12.8 ± 1.45.

CONCLUSION

This short-term follow-up study indicates SDIs remain functionally stable in the posterior jaws of treated GAgP patients.

Comparison of miRNA expression profiles in individuals with chronic or aggressive periodontitis

OBJECTIVES

MicroRNAs (miRNAs) may play an important role in inflammatory response. However, the involvement of miRNAs in the pathogenesis of periodontitis is unclear. The present study aimed to compare the miRNA expression profiles in individuals with chronic (CP) or aggressive (AP) periodontitis.

MATERIALS AND METHODS

Eighteen non-smoker individuals (CP = 9 and AP = 9) without any history of systemic diseases or previous periodontal therapies were selected at the Clinics of Periodontology from the Federal University of Minas Gerais. Gingival tissue samples were collected during the initial periodontal therapy. miRNAs were isolated, and expression patterns of 754 miRNAs were assessed with a quantitative miRNA PCR array. miRNAs expression profiles were compared between CP and AP groups.

RESULTS

There were no differences observed in the miRNAs expression profiles between CP and AP (p > 0.05). According to the microarray analyses, the most expressed miRNAs in both groups were hsa-miR-1274b, hsa-let-7b-5p, hsa-miR-24-3p, hsa-miR-19b-3p, hsa-miR-720, hsa-miR-126-3p, hsa-miR-17-3p and hsa-miR-21-3p.

CONCLUSION

Findings suggested no differences in miRNAs expression profiles between chronic and aggressive forms of periodontitis. The overexpression of specific miRNAs could provide insights into the pathogenesis of both forms of the disease.