Periodontal disease epidemiology - learned and unlearned?

Periodontitis Home Screening with Mouth Rinse Cut-Off 20 Ng/mL aMMP-8 Test and Mobile Application

Background: In this study, we describe a method by which a patient can independently assess their own periodontitis risk, for example, at home, with a mobile application. The aim of the study is to use active matrix metalloproteinase aMMP-8 mouth rinse cut-off 20 ng/mL point-of-care testing (POCT) and a polynomial function to reveal patients' statistical risk of periodontitis. Methods: The polynomial function presented in this study was modeled with multiple logistic regression and the function estimates the risk of periodontitis using a probability measure. To investigate variables associated with periodontitis, we used data from adult patients visiting dental clinics in Thessaloniki, Greece. Results: The research results revealed that with appropriate information it is possible to obtain sufficient accuracy about a patient's potential risk of periodontitis. The function for estimating risk of periodontitis is PERIORISK = (1 + e-(3.392×X1+0.002×X2+1.858×X3-9.151))-1, where X1 = aMMP-8 test result and tobacco smoking status, X2 = age × waist circumference and X3 = patient's individual and parental history of diabetes. Conclusions: The prediction of periodontitis risk using an aMMP-8 test and a polynomial function seems to be a useful, non-invasive, safe-to-use and cost-effective tool for all people. Overall, in the model created, mouth rinse cut-off 20 ng/mL aMMP-8 test result, age, waist circumference, tobacco smoking status and patient's individual and parental history of diabetes were found to be good factors explaining the risk of periodontitis.

Periodontal diseases in Africa

Periodontal diseases, a group of complex conditions marked by an excessive immune response and periodontal tissue destruction, are a global health concern. Since 1990, the incidence of these diseases has doubled, with Western sub-Saharan Africa experiencing the highest burden. Accurate diagnosis and case identification are crucial for understanding the etiology, features of disease, research, treatment and prevention. Modern perspectives on periodontal disease classification are based on commonality among those affected. However, current literature is often plagued by methodological inconsistencies and focused on disease mechanisms in European populations. Health inequalities in low- and middle-income countries (LMICs) are exacerbated by these challenges, with sub-Saharan Africa, and Nigeria specifically, facing unique difficulties such as clinical personnel shortages and limited research infrastructure. This review explored disparities in periodontal disease research, care and outcomes in African populations. We highlighted these disparities and identified the factors contributing to inequities in periodontal health outcomes. We further demonstrated the critical need for inclusive and equitable healthcare and research practices tailored to the unique challenges faced by diverse populations and regions with limited resources. Addressing these disparities is essential for ensuring that advancements in healthcare are accessible to all, thereby improving global oral health and general health.

Therapeutic Effects of Hinokitiol through Regulating the SIRT1/NOX4 against Ligature-Induced Experimental Periodontitis

Hinokitiol (HKT) is one of the essential oil components found in the heartwood of Cupressaceae plants, and has been reported to have various bioactive effects, including anti-inflammatory effects. However, the improving effect of HKT on periodontitis, which is characterized by periodontal tissue inflammation and alveolar bone loss, has not been clearly revealed. Therefore, we investigated the periodontitis-alleviating effect of HKT and the related molecular mechanisms in human periodontal ligament cells. According to the study results, HKT downregulated SIRT1 and NOX4, which were increased by Porphyromonas gingivalis Lipopolysaccharide (PG-LPS) stimulation and were found to regulate pro-inflammatory mediators and oxidative stress through SIRT1/NOX4 signals. Additionally, by increasing the expression of osteogenic makers such as alkaline phosphatase, osteogenic induction of human periodontal ligament (HPDL) cells, which had been reduced by PG-LPS, was restored. Furthermore, we confirmed that NOX4 expression was regulated through regulation of SIRT1 expression with HKT. The in vitro effect of HKT on improving periodontitis was proven using the periodontal inflammation model, which induces periodontal inflammation using ligature, a representative in vivo model. According to in vivo results, HKT alleviated periodontal inflammation and restored damaged alveolar bone in a concentration-dependent manner in the periodontal inflammation model. Through this experiment, the positive effects of HKT on relieving periodontal tissue inflammation and recovering damaged alveolar bone, which are important treatment strategies for periodontitis, were confirmed. Therefore, these results suggest that HKT has potential in the treatment of periodontitis.

Justification for the 2017 periodontitis classification in the light of the Checklist for Modifying Disease Definitions: A narrative review

Once a while, disease classifications have needed revision because new knowledge has accumulated, and new technologies and better treatments have emerged. Changes made to disease classifications should be trustworthy and openly justified. The periodontitis definition and classification system was changed in 2017 by the 'World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions'. The workshop, comprising clinicians and researchers, resulted in the production of a 23-article special issue that introduced the new definitions and classifications of periodontitis. In this narrative review, we critically review how the changes made to the periodontitis definition and classification were justified in the light of the Checklist for Modifying Disease Definitions. Under each of the eight items of the checklist, we have discussed how the item was or could have been considered in the light of the checklist and its guidance. In our view, the new definition and classification of periodontitis was presented in an understandable way, even though the changes from the previous definition were not made visible. However, the issues of (1) estimated changes in prevalence or incidence, (2) triggers for the change, (3) prognostic ability, (4) repeatability or reproducibility, (5) incremental benefits, (6) incremental harms or (7) net benefits and harms related to the introduction of new classification were not considered in the way suggested in the checklist. Thereby, a balanced assessment of potential benefits and harms associated with the new periodontitis classification system was not presented, and to a large extent it remains unknown if the use of the new classification system will provide more net benefits to patients and to the community than previous systems. It is our view that patients and societies deserve transparent and balanced assessments of the potential benefits and harms associated with the periodontitis classification. Importantly, these should reflect the values and preferences also of the patients and the wider community and consider the impact on resource usage.

The Role of Dyslipidemia in Periodontitis

Studies have suggested an important role of dyslipidemia, a condition with alterations in blood lipid levels, in promoting an additional effect on periodontal breakdown. Thus, this study aimed to explore the theoretical pathways associated with dyslipidemia and periodontitis. We used data from 11,917 US adults with complete periodontal examinations participating in the Third National Health and Nutrition Examination Survey (NHANES III). Our hypothesis was tested using structural equation modelling (SEM). Dyslipidemia was defined according to the National Cholesterol Education Program (NCEP-ATP III) and periodontitis as a latent variable reflecting the shared variance of the number of surfaces with periodontal pocket depth [PPD] = 4 mm, PPD = 5 mm, PPD ≥ 6 mm, clinical attachment level [CAL] = 4 mm, CAL = 5mm, CAL ≥ 6 mm, and furcation involvement. The model also considered distal determinants (age, sex, and socioeconomic status) and proximal determinants (HbA1c, smoking and alcohol consumption, and obesity). The model showed sufficient global fit (Root Mean Squared Error of Approximation = 0.04, 90%CI = 0.04−0.05, Tucker−Lewis Index = 0.93, Comparative Fit Index = 0.95). Age, sex, socioeconomic status, obesity, and smoking were directly associated with periodontitis (p < 0.01). Dyslipidemia revealed a significant direct effect on periodontitis (standardized coefficient [SC] = 0.086, SE 0.027; p < 0.01), also mediated via an indirect pathway through HbA1c (SC = 0.021; SE 0.010; p = 0.02) and obesity (SC = 0.036; SE 0.012; p < 0.01) and resulted in a total effect on periodontitis. Dyslipidemia was associated with periodontitis through a direct pathway and indirectly through HbA1c and obesity in the US population. These results support the need for a multi-professional approach to tackling oral and noncommunicable diseases (NCDs), directed at their common risk factors.

Oral Lesions Associated with COVID-19 and the Participation of the Buccal Cavity as a Key Player for Establishment of Immunity against SARS-CoV-2

BACKGROUND

Some oral lesions have been described in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); the possibility has been raised that the buccal lesions observed in patients with the coronavirus disease 2019 (COVID-19) are due to this virus and the patient's systemic condition. The aim of this review was to integrate the knowledge related to the oral lesions associated with COVID-19 and the participation of the buccal cavity in the establishment of immunity against SARS-CoV-2.

METHODS

A literature search on the manifestations of buccal lesions from the beginning of the pandemic until October 2021 was carried out by using the PubMed database. A total of 157 scientific articles were selected from the library, which included case reports and reports of lesions appearing in patients with COVID-19.

RESULTS

Oral lesions included erosions, ulcers, vesicles, pustules, plaques, depapillated tongue, and pigmentations, among others. The oral cavity is a conducive environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, immunodeficiencies, and autoimmunity primarily.

CONCLUSIONS

The oral cavity is an accessible and privileged environment for the interaction of SARS-CoV-2 with the mucosal immune system and target cells; the direct effects of the virus in this cavity worsen the antiviral inflammatory response of underlying oral disorders, in particular those related to immunodeficiencies and autoimmunity.

Paraprobiotics in Non-Surgical Periodontal Therapy: Clinical and Microbiological Aspects in a 6-Month Follow-Up Domiciliary Protocol for Oral Hygiene

Periodontal disease represents a progressive destruction of tooth-supporting tissues. Recently, paraprobiotics are regarded as an adjunctive therapy to the non-surgical Scaling-and-Root-Planing (SRP). The aim of this study is to evaluate the efficacy of two new formulations of paraprobiotics, a toothpaste and a mouthwash, respectively, for the domiciliary hygiene. A total of 40 patients were randomly assigned to the following domiciliary treatments: Group 1 (SRP + Curasept Intensive Treatment 0.2% chlorhexidine) (control) and Group 2 (SRP + Biorepair Peribioma toothpaste + Biorepair Peribioma Mousse mouthwash) (trial). At baseline (T0) and after 3 and 6 months (T1-T2), periodontal clinical (Bleeding on Probing, Probing Pocket Depth, Clinical Attachment Loss, Bleeding Score, Sulcus Bleeding Index, Plaque Index, Approximal Plaque Index, Adherent Gingiva, Gingival Recession, and Pathological Sites) and microbiological parameters (Pathological Bacteria, Saprophytic Bacteria, Enlarged Red Complex, Red Complex, Orange Complex, and counts of Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensys, Treponema denticola, Prevotella intermedia, and Fusobacterium nucleatum). The use of the experimental products resulted in a significant reduction of most of the clinical indices assessed, which occurred at a major degree with respect to the conventional chlorhexidine considered as control. Additionally, after 6 months of use, the abovementioned products significantly decreased the percentage of pathological bacteria and the counts of those bacteria constituting the "Red Complex", more related to the periodontal disease. Accordingly, the paraprobiotics-based products tested in this study seem to represent a valid support to SRP with a benefit on both clinical indices and on specific periodontopathogens.

Home Oral Care of Periodontal Patients Using Antimicrobial Gel with Postbiotics, Lactoferrin, and Aloe Barbadensis Leaf Juice Powder vs. Conventional Chlorhexidine Gel: A Split-Mouth Randomized Clinical Trial

Periodontitis is a progressive destruction of both soft and hard tooth-supporting tissues. In the last years, probiotics have been proposed as a support to the gold standard treatment scaling and root planing (SRP), but no extensive literature is present as regards the effect of the more recent postbiotics. Thirty patients subjected to SRP were randomly assigned to two domiciliary hygiene treatments based on the following oral gels: the postbiotics-based Biorepair Parodontgel Intensive (Group 1) and the chlorhexidine-based Curasept Periodontal Gel (Group 2). At baseline (T₀) and after 3 and 6 months (T₁–T₂), the following periodontal clinical parameters were recorded: Probing Pocket Depth (PPD), recession, dental mobility, Bleeding on Probing (BoP), and Plaque Control Record (PCR). A significant intragroup reduction was assessed in both groups for PPD, BoP, and PCR; conversely, recession significantly increased in both groups, whereas dental mobility did not vary. As regards intergroup comparisons, no statistically significant differences were assessed. Both gels, respectively, containing antioxidant natural ingredients and chlorhexidine, are effective for the domiciliary treatment of periodontitis. Further studies are required to evaluate the singular chemical compounds of the gels expected to exert the beneficial action assessed in this preliminary study.

Nrf2 in the Field of Dentistry with Special Attention to NLRP3

The aim of this review article was to summarize the functional implications of the nuclear factor E2-related factor or nuclear factor (erythroid-derived 2)-like 2 (Nrf2), with special attention to the NACHT (nucleotide-binding oligomerization), LRR (leucine-rich repeat), and PYD (pyrin domain) domains-containing protein 3 (NLRP3) inflammasome in the field of dentistry. NLRP3 plays a crucial role in the progression of inflammatory and adaptive immune responses throughout the body. It is already known that this inflammasome is a key regulator of several systemic diseases. The initiation and activation of NLRP3 starts with the oral microbiome and its association with the pathogenesis and progression of several oral diseases, including periodontitis, periapical periodontitis, and oral squamous cell carcinoma (OSCC). The possible role of the inflammasome in oral disease conditions may involve the aberrant regulation of various response mechanisms, not only in the mouth but in the whole body. Understanding the cellular and molecular biology of the NLRP3 inflammasome and its relationship to Nrf2 is necessary for the rationale when suggesting it as a potential therapeutic target for treatment and prevention of oral inflammatory and immunological disorders. In this review, we highlighted the current knowledge about NLRP3, its likely role in the pathogenesis of various inflammatory oral processes, and its crosstalk with Nrf2, which might offer future possibilities for disease prevention and targeted therapy in the field of dentistry and oral health.

Management of Gingival Bleeding in Periodontal Patients with Domiciliary Use of Toothpastes Containing Hyaluronic Acid, Lactoferrin, or Paraprobiotics: A Randomized Controlled Clinical Trial

Periodontitis is an irreversible oral disease causing the destruction of tooth-supporting tissues. In addition to scaling and root planing (SRP) procedures, patients should achieve a correct domiciliary oral hygiene in order to maintain a healthy status. The aim of the present study was to evaluate the efficacy of different toothpastes in reducing gingival bleeding in periodontal patients. In addition to a professional treatment of SRP, 80 patients were randomly divided into four groups according to the toothpaste assigned for the daily domiciliary use using an electric toothbrush: Group 1 (Biorepair Gum Protection), Group 2 (Biorepair Plus Parodontgel), Group 3 (Biorepair Peribioma PRO), and Group 4 (Meridol Gum Protection) (control group). After baseline (T0), patients were visited after 15 days (T1), 3 months (T2), and 6 months (T3). At each appointment, the following periodontal indexes were assessed: bleeding on probing (BoP), full-mouth bleeding score (FMBS), and modified sulcus bleeding index (mSBI). All the experimental toothpastes caused an immediate significant modification of the three clinical indexes measured, except for the control product. Biorepair Peribioma PRO, with its paraprobiotic content, was also the only toothpaste causing a prolonged effect, reducing BoP even at T3. Accordingly, both hyaluronic acid and lactoferrin appear as reliable supports for the domiciliary management of periodontal disease. In spite of this, paraprobiotics are likely to show the most important benefit thanks to their immunomodulating mechanism of action.

Poor Dietary Habits: A Function of Online Food Delivery Fad among Medical and Dental College Students in India

Background

Globalization has impacted our food choice and the booming online food industry has made it available at the click of a button. Students staying away from home often fail to maintain a healthy diet and lifestyle, impacting their health.

Methods

A survey was conducted amongst interns of medical and dental colleges in Delhi. Simple Random Sampling was done to select every alternate intern as per the list provided by the colleges. The survey included questions on dietary, fitness and food hygiene habits and dental history. Demographic details such as height weight and living arrangements were collected. Dietary habits score and Fitness & Food hygiene score was calculated based on pre-set criteria. Association of poor dietary habits and hygiene with BMI, living conditions and dental history was determined.

Results

One-fourth of the population was either overweight or obese. Poor, fair and good dietary habits was seen in 8.9%, 69.8% and 21.4% respectively. Poor, fair and good fitness and food hygiene was seen in 56.3%, 39.6% and 4.2% respectively. Obesity was significantly associated with poor fitness scores and with tendency to order junk food. Consumption of sugary food was associated with positive dental history, and those living with parents displayed good dietary habit score.

Conclusion

Students with high stress levels and living away from home are susceptible to poor dietary routine which impacts both their health and academic performance. Identifying these problems and triggers which induce such unhealthy lifestyle behaviour can go a long way in controlling the resultant health problems.

CLINICAL EFFICACY OF PROBIOTICS AS AN ADJUNCTIVE THERAPY TO SCALING AND ROOT PLANNING IN THE MANAGEMENT OF PERIODONTITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRAILS

OBJECTIVES

To evaluate the efficacy of probiotics as an adjunctive therapy to scaling and root planning treatment (SRP) in the management of periodontitis.

METHODS

PubMed, Embase, Web of science, SCOPUS and the Cochrane library were systematically searched to identify eligible studies. Stata 12.0 software was used to calculate the weighted mean differences (WMD) and 95% confidential interval (CI). The primary outcomes were clinical attachment level (CAL), probing pocket depth (PPD) and bleeding on probing (BOP).

RESULTS

Twenty-four randomized controlled trials (RCT) were included in the meta-analysis. The pooled results showed CAL gain (WMD: 0.20, 95% CI 0.09 to 0.31), PPD reduction (WMD: -0.31, 95% CI -0.52 to -0.10) and BOP reduction (WMD: -2.98, 95% CI -4.70 to -1.26) in the SRP+ probiotics group were significantly improved compared to control group at 3 months follow-up, but no significant difference was observed at 6 months. In addition, the probiotics administration could improve Plaque index (WMD: -0.30, 95% CI -0.59 to -0.05) and Gingival index (WMD: -0.46, 95% CI -0.71 to -0.21) at short term.

CONCLUSIONS

The results support the clinical efficacy of probiotics as an adjunctive therapy to SRP in the management of periodontitis at least 3 months follow-up. Within the limits of the evidence, the long-term efficacy needs to further confirm.

The Oral Microbiome in Periodontal Health

The estimation of oral microbiome (OM) taxonomic composition in periodontally healthy individuals can often be biased because the clinically periodontally healthy subjects for evaluation can already experience dysbiosis. Usually, they are included just based on the absence of clinical signs of periodontitis. Additionally, the age of subjects is used to be higher to correspond well with tested groups of patients with chronic periodontitis, a disorder typically associated with aging. However, the dysbiosis of the OM precedes the clinical signs of the disease by many months or even years. The absence of periodontal pockets thus does not necessarily mean also good periodontal health and the obtained image of "healthy OM" can be distorted.To overcome this bias, we taxonomically characterized the OM in almost a hundred young students of dentistry with precise oral hygiene and no signs of periodontal disease. We compared the results with the OM composition of older periodontally healthy individuals and also a group of patients with severe periodontitis (aggressive periodontitis according to former classification system). The clustering analysis revealed not only two compact clearly separated clusters corresponding to each state of health, but also a group of samples forming an overlap between both well-pronounced states. Additionally, in the cluster of periodontally healthy samples, few outliers with atypical OM and two major stomatotypes could be distinguished, differing in the prevalence and relative abundance of two main bacterial genera: Streptococcus and Veillonella. We hypothesize that the two stomatotypes could represent the microbial succession from periodontal health to starting dysbiosis. The old and young periodontally healthy subjects do not cluster separately but a trend of the OM in older subjects to periodontitis is visible. Several bacterial genera were identified to be typically more abundant in older periodontally healthy subjects.

Individual predisposition and the intricate interplay between systemic biomarkers and periodontal risk in a general population

BACKGROUND

Increasing age is associated with systemic diseases as well as with periodontal diseases. We wondered whether a biological age score constructed exclusively from systemic biomarkers would reflect periodontal risk factors at baseline and tooth loss as well as periodontal outcome during 10 years follow-up.

METHODS

From the Study of Health in Pomerania (SHIP) 2256 participants (1072 male, 1184 female) were studied for the relationship of the systemic biomarkers glycated hemoglobin (HbA1c), low density lipoprotein cholesterol (LDL), fibrinogen, white blood cell count, blood pressure, and waist circumference to their age. Construction of a biological age (BA) score allowed its comparison with the participants' actual chronological age (CA) and their predisposition to periodontal disease.

RESULTS

Though nearly identical in CA, participants appearing younger than their true age had a significantly reduced burden of periodontal risk factors. If BA > CA, then risk factors were more frequent including smoking, oral hygiene, dental visits, education, and income. After 10 years, in participants with identical CA, tooth loss followed their BA calculated at baseline, that is, with BA > CA fewer teeth were preserved. Similarly, periodontal measures varied according to BA; sex differences were obvious. Most significant were BA-related differences in inflammatory and anthropometry parameters.

CONCLUSIONS

The results support the assumption that risk profiles aggregated in BA constitute a characteristic susceptibility pattern unique to each individual, common to both systemic and periodontal diseases. Although BA was constructed exclusively from systemic measures at baseline, BA reflects the oral conditions at follow-up.

Probiotic Alternative to Chlorhexidine in Periodontal Therapy: Evaluation of Clinical and Microbiological Parameters

Periodontitis consists of a progressive destruction of tooth-supporting tissues. Considering that probiotics are being proposed as a support to the gold standard treatment Scaling-and-Root-Planing (SRP), this study aims to assess two new formulations (toothpaste and chewing-gum). 60 patients were randomly assigned to three domiciliary hygiene treatments: Group 1 (SRP + chlorhexidine-based toothpaste) (control), Group 2 (SRP + probiotics-based toothpaste) and Group 3 (SRP + probiotics-based toothpaste + probiotics-based chewing-gum). At baseline (T0) and after 3 and 6 months (T1-T2), periodontal clinical parameters were recorded, along with microbiological ones by means of a commercial kit. As to the former, no significant differences were shown at T1 or T2, neither in controls for any index, nor in the experimental groups for adherent gingiva and gingival recession. Conversely, some significant differences were found in Group 2 and 3 for the other clinical indexes tested. Considering microbiological parameters, no significant differences were detected compared to baseline values for any group, except in Group 2 and 3 at T2 only for the percentage of the orange complex pathogens and for the copies/microliter of Prevotella intermedia and Fusobacterium nucleatum. Accordingly, although colonization of probiotic bacteria has not been assessed in this study, the probiotics tested represent a valid support to SRP with a benefit on several clinical indexes and on specific periodontopathogens. Despite this promising action, the relationship between the use of probiotics and improvement in clinical parameters is still unclear and deserves to be further explored.

Diagnostic Accuracy of Oral Fluids Biomarker Profile to Determine the Current and Future Status of Periodontal and Peri-Implant Diseases

Severe periodontitis is ranked as the sixth most prevalent disease affecting humankind, with an estimated 740 million people affected worldwide. The diagnosis of periodontal diseases mainly relies upon assessment of conventional clinical parameters. However, these parameters reflect past, rather than current, clinical status or future disease progression and, likely, outcome of periodontal treatment. Specific and sensitive biomarkers for periodontal diseases have been examined widely to address these issues and some biomarkers have been translated as point-of-care (PoC) tests. The aim of this review was to provide an update on PoC tests for use in the diagnosis and management of periodontal diseases. Among the PoC tests developed so far, active matrix metalloproteinase-8 has shown promising results in terms of diagnostic and prognostic values. However, further studies are required to increase the sensitivity and specificity via combining more than one biomarker and merging these test kits with periodontal risk assessment tools. Furthermore, the validity of these test kits needs to be investigated by applying the results in further independent studies and the impact on these test kits', together with the results of risk factors for periodontal diseases, such as diabetes and smoking, also needs to be examined.

A public health approach for prevention of periodontal disease

Upwards of 1 in 10 adults worldwide may be affected by severe periodontitis, making the disease more prevalent than cardiovascular disease. Despite its global scope, its impact on pain, oral function, and the wellbeing of individuals, and the disproportionate burden of disease and the socioeconomic impact on communities, the perception that periodontal disease is a public health problem remains low. Although there have been substantial improvements in our understanding of the etiology of periodontal disease and how we can prevent and control it, these advances have been primarily focused on individual, patient-focused approaches. The prevention of periodontal disease depends on improving currently available individual interventions and on determining what public health interventions can be effective and sustainable under real-life conditions. Currently, public health approaches for periodontal disease prevention and control are lacking. This review traces the historical strategies for prevention of periodontal disease in an epidemiologic transition context, using a modified model developed for cardiovascular disease, and presents a possible public health approach. Improving periodontal disease prevention and control will need to take into consideration the core activities of a public health approach: assessment, policy development, and assurance.

Current concepts and an alternative perspective on periodontal disease

BACKGROUND

Epidemiological data from countries worldwide show a consistent pattern implying that a fraction of around 10% of those over 40-50 years in all populations will exhibit severe periodontitis with the potential risk of losing teeth during their life-time. The subgingival microbiota shows striking similarities between populations irrespective of disease severity and can only marginally explain the clinical pattern. It is also difficult to explain this pattern by genetic and acquired risk factors such as systemic disease (e.g. diabetes) or habits (e.g. smoking) even if they may have a confounding effect on the disease.

MAIN TEXT

Inflammation of the gingiva appears to be a normal and physiological response to the presence of commensal bacteria along the gingival crevice and in the dental biofilm. Over many years of exposure to the dental biofilm, the chronic inflammation in the gingiva gradually results in a loss of attachment and bone loss. Numerous laboratory and clinical studies have provided insight into the potential role of determinants that are associated with periodontitis. However, it has been difficult to relate the findings to the pattern of the distribution of the disease observed in epidemiological studies. We propose a simple and parsimonious model that considers all the multitude of potential determinants as creating effectively random noise within the dental biofilm to which the tissues react by accumulating the effects of this noise.

CONCLUSIONS

We suggest that such a model can explain many of the epidemiological features of periodontal breakdown over time, and we discuss its clinical implications.

Periodontitis phenotypes and clinical response patterns to non-surgical periodontal therapy: reflections on the new periodontitis classification

We aimed to identify response patterns to non-surgical periodontal therapy and to investigate whether the new classification system for periodontitis reflects response to treatment after 1 yr. At baseline, data on sociodemographic status, smoking, and diabetes were obtained from participants with periodontal disease. Clinical periodontal data and subgingival plaque were also collected. Participants underwent non-surgical periodontal therapy, and after 3 and 12 months, clinical data were reassessed. Factor analyses, group-based-trajectory modeling, and mixed-effects regression models were used for data analysis. Factor analysis of the baseline periodontal parameters revealed two different periodontitis dimensions: 'moderate' and 'severe'. Two response patterns for each of these periodontitis dimensions were identified. Periodontal therapy had a beneficial effect on both 'moderate' and 'severe' periodontitis; however, individuals with higher levels of disease at baseline experienced greater treatment effect. Regarding the new classification system, while the staging component distinguished different levels of 'moderate' and 'severe' periodontitis before and after treatment, the grading component did not. This study shows the beneficial effect of non-surgical periodontal therapy on both 'moderate' and 'severe' periodontitis. However, the benefit was limited among individuals with low levels of disease. The new classification system did not adequately reflect the periodontal response to therapy in this patient group.

Effects of 1,25-dihydroxyvitamin D3 on experimental periodontitis and AhR/NF-κB/NLRP3 inflammasome pathway in a mouse model

Vitamin D has been known to have important regulatory functions in inflammation and immune response and shows inhibitory effects on experimental periodontitis in animal models. However, the potential mechanism has yet to be clarified. Recent studies have highlighted Aryl hydrocarbon receptor (AhR) and its downstream signaling as a crucial regulator of immune homeostasis and inflammatory regulation.

OBJECTIVE

This study aimed to clarify the effect of 1,25-dihydroxyvitamin D3 (VD3) on experimental periodontitis and AhR/nuclear factor-κB (NF-κB)/NLR pyrin domain-containing 3 (NLRP3) inflammasome pathway in the gingival epithelium in a murine model.

METHODOLOGY

We induced periodontitis in male C57BL/6 wild-type mice by oral inoculation of Porphyromonas gingivalis (P. gingivalis), and subsequently gave intraperitoneal VD3 injection to the mice every other day for 8 weeks. Afterwards, we examined the alveolar bone using scanning electron microscopy (SEM) and detected the gingival epithelial protein using western blot analysis and immunohistochemical staining.

RESULTS

SEM images demonstrated that alveolar bone loss was reduced in the periodontitis mouse model after VD3 supplementation. Western blot analyses and immunohistochemical staining of the gingival epithelium showed that the expression of vitamin D receptor, AhR and its downstream cytochrome P450 1A1 were enhanced upon VD3 application. Additionally, VD3 decreased NF-κB p65 phosphorylation, and NLRP3, apoptosis-associated speck-like protein, caspase-1, interleukin-1β (IL-1β) and IL-6 protein expression.

CONCLUSIONS

These results implicate the alleviation of periodontitis and the alteration of AhR/NF-κB/NLRP3 inflammasome pathway by VD3 in the mouse model. The attenuation of this periodontal disease may correlate with the regulation of AhR/NF-κB/NLRP3 inflammasome pathway by VD3.

Impact of smoking on gingival inflammation in representative samples of three South American cities

The aim of this study was to investigate the impact of smoking on gingival inflammation in a representative sample of 1,650 adults from Santiago (Chile), Porto Alegre (Brazil), and Tucumán (Argentina). A questionnaire was administered to participants to gather demographic and behavioral characteristics, including smoking habits. The participants were clinically examined to obtain gingival index (GI), gingival bleeding index (GBI), visible plaque index (VPI), and calculus presence values. Gingival inflammation was defined as a mean GI > 0.5. Heavy smokers presented significantly lower levels of gingival inflammation, as reflected by both GI and GBI, than both light and moderate smokers, despite their having increased amounts of plaque and calculus. Being 50 years old or older [odds ratio (OR), 1.93], a VPI ≥ 30% (OR, 28.1), and self-reported diabetes (OR, 2.79) were positively associated with detection of gingival inflammation. In conclusion, the occurrence of clinically detectable gingival inflammation was lower in heavy smokers than light and moderate smokers. Older age, diabetes, and visible plaque emerged as risk indicators of gingivitis. Plaque and gingival indices are significantly associated regardless of the smoking status.

Low-intensity pulsed ultrasound promotes tissue regeneration in rat dental follicle cells in a porous ceramic scaffold

The aim of this study was to investigate the effects of low-intensity pulsed ultrasound (LIPUS) on the osteogenic differentiation of dental follicle cells (DFCs) in vitro and on the regenerative effects of DFC-OsteoBoneTM complexes in vivo. DFCs were isolated and characterized. In the in vitro study, DFCs were cultured in an osteogenic medium in the presence or absence of LIPUS. The expression levels of ALP, Runx2, OSX, and COL-I mRNA were analyzed using real-time polymerase chain reaction (RT-PCR) on day 7. Alizarin red staining was performed on day 21. The state of the growth of the DFCs that were seeded on the scaffold at 3, 5, 7, and 9 days was detected by using a scanning electron microscope. In our in vivo study, 9 healthy nude mice randomly underwent subcutaneous transplantation surgery in one of three groups: group A, empty scaffold; group B, DFCs + scaffold; and group C, DFCs + scaffold + LIPUS. After 8 weeks of implantation, a histological analysis was performed by HE and Mason staining. Our results indicate that LIPUS promotes the osteogenic differentiation of DFCs by increasing the expression of the ALP, Runx2, OSX, and COL-I genes and the formation of mineralized nodules. The cells can adhere and grow on the scaffolds and grow best at 9 days. The HE and Mason staining results showed that more cells, fibrous tissue and blood vessels could be observed in the DFCs + scaffold + LIPUS group than in the other groups. LIPUS could promote the osteogenic differentiation of DFCs in vitro and promote tissue regeneration in a DFCs-scaffold complex in vivo. Further studies should be conducted to explore the underlying mechanisms of LIPUS.

Importance of Virulence Factors for the Persistence of Oral Bacteria in the Inflamed Gingival Crevice and in the Pathogenesis of Periodontal Disease

Periodontitis is a chronic inflammation that develops due to a destructive tissue response to prolonged inflammation and a disturbed homeostasis (dysbiosis) in the interplay between the microorganisms of the dental biofilm and the host. The infectious nature of the microbes associated with periodontitis is unclear, as is the role of specific bacterial species and virulence factors that interfere with the host defense and tissue repair. This review highlights the impact of classical virulence factors, such as exotoxins, endotoxins, fimbriae and capsule, but also aims to emphasize the often-neglected cascade of metabolic products (e.g., those generated by anaerobic and proteolytic metabolism) that are produced by the bacterial phenotypes that survive and thrive in deep, inflamed periodontal pockets. This metabolic activity of the microbes aggravates the inflammatory response from a low-grade physiologic (homeostatic) inflammation (i.e., gingivitis) into more destructive or tissue remodeling processes in periodontitis. That bacteria associated with periodontitis are linked with a number of systemic diseases of importance in clinical medicine is highlighted and exemplified with rheumatoid arthritis, The unclear significance of a number of potential "virulence factors" that contribute to the pathogenicity of specific bacterial species in the complex biofilm-host interaction clinically is discussed in this review.

The effect of platelet lysate in culture of PDLSCs: an in vitro comparative study

Background

Cellular therapy clinical applications require large-scale production of stem cells. Therefore, abundance, ease of isolation, and proliferative potential are the most important factors in choosing the appropriate source of cells for transplantation studies. Multipotent stem cells obtained from periodontal ligament (PDL) can be used in periodontal tissue regeneration. In this study, we aimed to evaluate and compare the characteristics of periodontal ligament stem cells (PDLSCs), extracted by either enzymatic digestion or explant methods, and expanded using two different serum types: fetal bovine serum (FBS) and xeno-free platelet lysate (PL).

Methods

Expanded PDLSCs were assessed for their proliferation capacity, surface markers expression, colony formation, differentiation potential and ability to self-renewal. Most importantly, PDLSCs were evaluated for their ability to produce osteoblasts in vitro.

Results

PDLSCs isolated by explant method and expanded in PL serve as a promising source of stem cells for osteoblasts regeneration. These cells showed higher proliferation capacity, they retained their stemness characteristics throughout the passages and they revealed an increase in the expression level of osteogenic markers, without showing any karyotypic abnormalities after cell expansion.

Conclusions

PDLSCs produced using explant extraction method and expanded in cell culture media supplemented with PL provide an excellent source of xeno-free cells for the generation of functional osteoblasts.

Quantification of TNF-α in Patients with Periodontitis and Type 2 Diabetes

OBJECTIVE

The present study aimed to compare variations in quantified tumor necrosis factor-alpha (TNF-α) levels in patients with periodontitis stage 2 grade B (POD2B) and/or type 2 diabetes (T2D) and to identify any relationships between this cytokine and these diseases.

METHODS

Levels of the cytokine TNF-α in gingival crevicular fluid in patients with POD2B and/or T2D were evaluated. A total of 160 subjects were distributed into four groups: those with POD2B (n=44); those with T2D (n=37); those with POD2B/T2D (n=40); and healthy subjects (n=39). Glycosylated hemoglobin (HbA1c) and blood glucose (BG) levels were quantified in each subject. Data were collected on body mass index (BMI), loss of insertion (LI), and probe depth (PD). Gingival crevicular fluid samples were collected from the most acutely affected periodontal pocket and gingival sulcus in each subject, and TNF-α was quantified by multiplex analysis.

RESULTS

Kruskal Wallis tests was used to identify differences in TNF-α levels, LI, PD, BMI, BG, and HbA1c by group. Differences (p<0.001) were found for LI, PD, BG, and HbA1c. A Spearman test was used to calculate possible correlations between TNF-α levels and LI or PD identified a weak but significant negative correlation of TNF-α with LI (Rho=-0199; p=0.012), and a moderately positive correlation of LI with PD (Rho=0.509; p < 0.001).

CONCLUSIONS

No variation was found between TNF-α levels and the presence of POD2B, POD2B/T2D, or T2D, suggesting the absence of any direct relationship between progression of these diseases and TNF-α levels. However, a correlation was present between low TNF-α concentrations and greater LI.

[Periodontal disease: epidemiological approaches for its analysis as a public health concern]

The way how health problems are defined allow conceptual and methodological developments that lead to different outcomes and specific analytical and preventive approaches to confront problems. This essay aims to show some of the main epidemiological approaches that have been used to address the oral health-disease process, in particular the periodontal disease. Regarding the latter, different approaches to their understanding are proposed, which have been influenced by the biological-curative model, whose scope is limited and focused on the identification of risk factors and on demonstrating causal relationships. However, more comprehensive alternatives are also portrayed from social epidemiology that include social determinants in the analysis of the health-disease process, which affects and influences this process in the communities.

Age and Periodontal Health - Immunological View

PURPOSE OF THE REVIEW

Aging clearly impacts a wide array of systems, in particular the breadth of the immune system leading to immunosenescence, altered immunoactivation, and coincident inflammaging processes. The net result of these changes leads to increased susceptibility to infections, increased neoplastic occurrences, and elevated frequency of autoimmune diseases with aging. However, as the bacteria in the oral microbiome that contribute to the chronic infection of periodontitis is acquired earlier in life, the characteristics of the innate and adaptive immune systems to regulate these members of the autochthonous microbiota across the lifespan remains ill defined.

RECENT FINDINGS

Clear data demonstrate that both cells and molecules of the innate and adaptive immune response are adversely impacted by aging, including in the oral cavity, yielding a reasonable tenet that the increased periodontitis noted in aging populations is reflective of the age-associated immune dysregulation. Additionally, this facet of host-microbe interactions and disease needs to accommodate the population variation in disease onset and progression, which may also reflect an accumulation of environmental stressors and/or decreased protective nutrients that could function at the gene level (ie. epigenetic) or translational level for production and secretion of immune system molecules.

SUMMARY

Finally, the majority of studies of aging and periodontitis have emphasized the increased prevalence/severity of disease with aging, all based upon chronological age. However, evolving areas of study focusing on "biological aging" to help account for population variation in disease expression, may suggest that chronic periodontitis represents a co-morbidity that contributes to "gerovulnerability" within the population.

Evaluating the validity and reliability of a visual dental scale for detection of periodontal disease (PD) in non-anesthetized dogs (Canis familiaris)

Periodontal disease is one of the most common conditions affecting companion dogs. The objectives of this cross-sectional study were: to determine 1) the agreement between visual assessments (VA) of periodontal disease (PD) performed on awake dogs and the reference standard (RS) of a dental examination and radiographs performed with the dog under general anesthesia, and 2) inter-rater reliability (IRR) for two individuals performing VAs of PD on the same dogs. One hundred and eight dogs were recruited from three veterinary practices. An oral examination and visual PD staging based on the American Veterinary Dental College’s (AVDC) 5-point scale was performed by the investigators prior to general anesthesia and the dental procedure. After the anesthetic evaluation and radiographs, the attending veterinarian staged each dog based on the AVDC’s 5-point scale. Agreement between the VA and RS as well as IRR were determined using percent agreement and a weighted kappa statistic. Eighty-nine dogs received a complete oral examination under general anesthesia with periodontal probing and full-mouth radiographs. Fifty-nine dogs received a VA by both raters. VA agreed with the RS 41.57% of the time with a weighted kappa of 0.42 (95% confidence interval 0.29–0.55), indicating moderate agreement. Between raters, VA agreed 61.02% of the time with a weighted kappa of 0.63 (95% confidence interval 0.49–0.76), indicating substantial IRR. The results of this study reinforce the idea that an oral examination in an awake dog can be a helpful screening tool, but should not be considered a comprehensive evaluation of periodontal health. In facilities housing large numbers of dogs such as shelters, breeding kennels, and research facilities, use of a VA can aid in identifying and prioritizing dogs most in need of procedures such as professional cleaning, periodontal treatment, including closed root planing, or surgical care.

Stress, salivary cortisol and periodontitis: A systematic review and meta-analysis of observational studies

OBJECTIVE

This meta-analysis aims to systematically assess whether periodontitis has a meaningful effect on salivary cortisol, reflecting changes on free blood cortisol levels.

DESIGN

The Cochrane Handbook and the PRISMA statement were used as reporting guidelines. The MEDLINE-PubMed, Google Scholar, EMBASE, and CENTRAL databases were searched until September 2017 to identify eligible studies, screened by seven independent authors and verified by an eighth. Studies comparing salivary cortisol level of periodontitis cases to controls were included. Data were extracted using a predefined table and since all papers were non-randomized clinical trials they were appraised using Downs and Black tool. DerSimonian random effects meta-analysis was performed using OpenMetaAnalyst.

RESULTS

Six cross-sectional studies were included, with 258 participants with chronic periodontitis and 72 with aggressive periodontitis, in a total of 573 participants. Overall results showed that aggressive periodontitis patients have, on average, 53% higher salivary cortisol levels than healthy controls 1.53 (1.11-2.12). Meta-regression exploring the relationship among salivary cortisol levels and periodontal measures, i.e., periodontitis severity, showed a global neutral effect, although this result requires future confirmation due to the low power of the model.

CONCLUSION

Observational studies results suggest that subjects with aggressive periodontitis have higher salivary cortisol levels than healthy ones or patients with chronic periodontitis. Such salivary cortisol response difference may have a negative impact on the periodontium, contributing to worse the burden of aggressive periodontitis disease. In the future, wide and well-designed longitudinal studies should be carried out in order to extensively confirm this possible effect, considering the complex nature of periodontitis and its many confounders factors that may contribute to this outcome.

Periodontal Disease and Risk of Bladder Cancer: A Meta-Analysis of 298476 Participants

Objective: It has been reported that the periodontal disease is linked to a number of malignant tumors such as lung cancer and pancreatic cancer. In this study, we aimed to investigate the association of periodontal disease with risk of bladder cancer by a meta-analysis. Methods: PubMed, Scopus, ScienceDirect, and Chinese National Knowledge Infrastructure (CNKI) were searched for eligible publications up to December 15, 2017. Cohort and nested case-control studies on the association between periodontal disease and risk of bladder cancer were included. After study selection and data extraction, pooled hazard ratios (HRs) and their 95% confidence intervals (95%CIs) were calculated using a fixed-effect inverse-variance model. All analyses were performed using the RevMan 5.3 software. Results: Finally, five cohort studies were identified and included in this meta-analysis, involving 1,104 bladder cancer cases of 298,476 participants. Summary estimates based on adjusted data showed that periodontal disease was not significantly associated with the risk of bladder cancer (HR = 1.09, 95% CI = 0.95-1.25, I2 = 0%). A similar result was also observed after cumulative, subgroup and sensitivity analyses. Conclusions: Current evidence from cohort studies suggests that patients with periodontal disease may not be at an increased risk of developing bladder cancer.

Ageing effects on humoral immune responses in chronic periodontitis

Periodontal disease is a dominant global bacterial infection that increases with ageing.

AIM

This report focuses on host adaptive immune responses in periodontitis. While experimental models and humans diagnosed with periodontitis demonstrate an antigenic specificity for particular oral bacteria, we have a limited understanding of (i) how ageing affects the adaptive immune responses to these bacteria that chronically colonize the oral cavity for decades prior to disease expression and (ii) how the magnitude and specificity of the response interface with pathogens that emerge within the bacterial ecology during exacerbations of disease.

MATERIALS AND METHODS

Serum antibody levels to a group of pathogenic and commensal oral bacteria were measured in a population of individuals from 21 to 74 years of age, stratified based on clinical status of the periodontium, smoking and sex.

RESULTS

Clinical parameters were not significantly different within health, gingivitis or periodontitis groups related to age. Antibody to oral pathogens and commensals was similar in different age groups in each of the clinical categories, with no age correlation noted in the periodontitis patients.

CONCLUSIONS

The adaptive immune responses to oral bacteria that chronically colonize the oral cavity appear generally unaffected by age, but clearly are linked to the extent of disease.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

IL-6 and TNF-α salivary levels according to the periodontal status in Portuguese pregnant women

Background

Periodontitis is associated with increased concentration of inflammatory markers and saliva has been proposed as a non-invasive diagnostic fluid in oral and systemic diseases. The levels of salivary biomarkers, such as cytokines, could potentially be used to distinguish periodontal healthy individuals from subjects with periodontal disease. The purpose of this study was to characterize the salivary levels of two inflammatory biomarkers associated with periodontitis, interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), in order to assess whether these cytokines salivary levels could potentially be used to complement periodontitis pregnant women diagnose.

Methods

Forty-four pregnant women were distributed into three groups, according to their periodontal status: healthy, mild/moderate periodontitis and severe periodontitis. Unstimulated saliva was collected and analysis of TNF-α and IL-6 salivary levels were performed with Immulite^®.

Results

Women with periodontitis exhibited significantly higher levels (p = 0.001) of salivary IL-6 and TNF-α compared with the healthy group: 25.1 (±11.2) pg/mL vs. 16.3 (±5.0) pg/mL and 29.7 (±17.2) pg/mL vs. 16.2 (±7.6) pg/mL, approximately 1.5 and 1.8 times more, respectively. Additionally, cytokines were significantly increased (p < 0.05) in severe periodontitis compared to periodontal healthy pregnant women.

Conclusions

These results revealed that IL-6 and TNF-α salivary biomarkers provide high discriminatory capacity for distinguishing periodontal disease from periodontal health in pregnant women.

Caries and Periodontitis: Contesting the Conventional Wisdom on Their Aetiology

We review the literature on the oral microbiome and the role of the microbiota in the development of dental caries and periodontitis. While most research has been focused on identifying one or more specific determinants of these diseases, the results have provided limited predictive value and have not been able to explain the variation in the distribution of these diseases observed in epidemiological or clinical studies. Drawing on existing knowledge about the nature of the oral microbiota, we suggest that a stochastic model based on the Weiner process provides simple and parsimonious explanations for the pathogenesis of both caries and periodontitis, making few assumptions, and providing explanations for phenomena that have hitherto proved difficult, or have required complex arguments, to explain. These diseases occur as the result of the dental hard tissues and periodontal tissues integrating the random "noise" caused by normal metabolic activities of commensal microorganisms in the dental biofilm. The processes that result in the progression and regression of caries and periodontitis may be considered as "natural," rather than pathological, even if, when left unchecked over long periods of time, they can result in the development of pathologies. The likelihood of progression or regression can be influenced by other determinants, but these processes will nevertheless occur in the absence of such influences. The distributional characteristics of the model approximate the findings of epidemiological studies indicating that, for both caries and periodontitis, there will be few sites affected in the early period after the eruption of the permanent dentition, but in those older there is an almost linear relationship with increasing age; furthermore, the longer a site survives without being affected, the less likely that it will be affected. We discuss the clinical and public health importance of these findings.

Comparative analysis of microbial sensing molecules in mucosal tissues with aging

Host-bacterial interactions at mucosal surfaces require recognition of the bacteria by host cells enabling targeted responses to maintain tissue homeostasis. It is now well recognized that an array of host-derived pattern recognition receptors (PRRs), both cell-bound and soluble, are critical to innate immune engagement of microbes via microbial-associated molecular patterns (MAMP). This report describes the use of a nonhuman primate model to evaluate changes in the expression of these sensing molecules related to aging in healthy gingival tissues. Macaca mulatta aged 3-24 years were evaluated clinically and gingival tissues obtained, RNA isolated and microarray analysis conducted for gene expression of the sensing pattern recognition receptors (PRRs). The results demonstrated increased expression of various PRRs in healthy aging gingiva including extracellular (CD14, CD209, CLEC4E, TLR4), intracellular (NAIP, IFIH1, DAI) and soluble (PTX4, SAA1) PRRs. Selected PRRs were also correlated with both bleeding on probing (BOP) and pocket depth (PD) in the animals. These findings suggest that aged animals express altered levels of various PRRs that could affect the ability of the tissues to interact effectively with the juxtaposed microbial ecology, presumably contributing to an enhanced risk of periodontitis even in clinically healthy oral mucosal tissues with aging.

Integrated biomarker profiling of smokers with periodontitis

BACKGROUND

In the context of precision medicine, understanding patient-specific variation is an important step in developing targeted and patient-tailored treatment regimens for periodontitis. While several studies have successfully demonstrated the usefulness of molecular expression profiling in conjunction with single classifier systems in discerning distinct disease groups, the majority of these studies do not provide sufficient insights into potential variations within the disease groups.

AIM

The goal of this study was to discern biological response profiles of periodontitis and non-periodontitis smoking subjects using an informed panel of biomarkers across multiple scales (salivary, oral microbiome, pathogens and other markers).

MATERIAL & METHODS

The investigation uses a novel ensemble classification approach (SVA-SVM) to differentiate disease groups and patient-specific biological variation of systemic inflammatory mediators and IgG antibody to oral commensal and pathogenic bacteria within the groups.

RESULTS

Sensitivity of SVA-SVM is shown to be considerably higher than several traditional independent classifier systems. Patient-specific networks generated from SVA-SVM are also shown to reveal crosstalk between biomarkers in discerning the disease groups. High-confidence classifiers in these network abstractions comprised of host responses to microbial infection elucidated their critical role in discerning the disease groups.

CONCLUSIONS

Host adaptive immune responses to the oral colonization/infection contribute significantly to creating the profiles specific for periodontitis patients with potential to assist in defining patient-specific risk profiles and tailored interventions.

Is periodontal disease a public health problem?

Clinically defined periodontal disease is highly prevalent, has considerable impacts on individuals and society and is costly to treat; the cost of dental care is the fourth highest costs of all diseases and consuming between 5 and 10% of all healthcare resources. Changes in the epidemiology of clinically defined periodontal diseases suggest that the prevalence of severe periodontal disease is low and rates of progression of periodontal destruction tend to be relatively slow. Current periodontal care modalities have a remarkably weak evidence base, with considerable resources allocated to fund interventions that include oral hygiene instruction, scale and polishes through to surgical interventions. The public health problem lies more in the failure in design of a contract between dental professionals and the state. Such a contract needs to recognise both the wider determinants of disease and the role that dental professionals could play: a contract that concentrated on rewarding outcomes, namely a diminution in treatment need, as opposed to one based simply on the number of interventions would be a major step forward.

Mangiferin inhibits lipopolysaccharide-induced production of interleukin-6 in human oral epithelial cells by suppressing toll-like receptor signaling

OBJECTIVE

Oral epithelial cells have currently been found to play an important role in inflammatory modulation in periodontitis. Mangiferin is a natural glucosylxanthone with anti-inflammatory activity. The aim of this study was to investigate the regulatory effect of mangiferin on lipopolysaccharide (LPS)-induced production of proinflammatory cytokine interleukin-6 (IL-6) in oral epithelial cells and the underlying mechanisms.

DESIGN

The levels of LPS-induced IL-6 production in OKF6/TERT-2 oral keratinocytes were detected using enzyme-linked immunosorbent assay (ELISA). The expression of Toll-like receptor (TLR) 2 and TLR4 was determined using western blot analysis. And the phosphorylation of TLR downstream nuclear factor-κB (NF-κB), p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinase (JNK) was examined using cell-based protein phosphorylation ELISA kits.

RESULTS

We found that mangiferin reduced LPS-upregulated IL-6 production in OKF6/TERT-2 cells. Additionally, mangiferin inhibited LPS-induced TLR2 and TLR4 overexpression, and suppressed the phosphorylation of NF-κB, p38 MAPK and JNK. Moreover, mangiferin repressed IL-6 production and TLR signaling activation in a dose-dependent manner after 24h treatment.

CONCLUSIONS

Mangiferin decreases LPS-induced production of IL-6 in human oral epithelial cells by suppressing TLR signaling, and this glucosylxanthone may have potential for the treatment of periodontitis.

Clinical research activity in periodontal medicine: a systematic mapping of trial registers

AIM

The primary aim of the study was to systematically map registration records on periodontal medicine in clinical trial registers. The secondary aim was to assess the evolution of periodontal medicine in clinical periodontal research as a whole.

MATERIAL AND METHODS

We searched all registration records related to periodontology in the World Health Organization International Clinical Trials Registry Platform. For registration records classified in the field of periodontal medicine, we assigned the 2015 MeSH(®) term for the most precisely corresponding systemic condition.

RESULTS

Fifty-seven systemic conditions have been hypothesized to be linked with periodontal diseases, covering nearly 2% of the diseases indexed in MeSH. In addition to diabetes, cardiovascular disease or preterm birth, other systemic conditions have been the subject of registration records, such as anaemia, liver diseases, dyspepsia or ankylosing spondylitis. A trend towards increasing diversification of systemic conditions has appeared over time. About a third of registration records in clinical periodontal research deals with periodontal medicine.

CONCLUSIONS

Periodontal medicine now constitutes an important part of clinical periodontal research. Research activity in periodontal medicine has grown continuously since the early 2000s, and exploration of registers gives a useful up-to-date snapshot of this constantly evolving field of research.

Cell-Based Approaches in Periodontal Regeneration: A Systematic Review and Meta-Analysis of Periodontal Defect Models in Animal Experimental Work

Various cell types have been assessed for experimental periodontal tissue regeneration in a variety of animal models. Nonetheless, the efficacy of cell-based approaches for periodontal regeneration is still controversial. Therefore, the purpose of this study was to systematically review cell-based approaches for periodontal regeneration in animal studies including a meta-analysis to obtain more clarity on their efficacy. The results of this systematic review and meta-analysis revealed that cell-based approaches have a favorable effect on periodontal tissue regeneration, as displayed by the positive effect of cell-based approaches on new bone, cementum, and periodontal ligament (PDL) formation in periodontal defects. Moreover, subgroup analysis showed a favorable effect on PDL formation by PDL-derived cells, but not by bone marrow mesenchymal stem cells (BMSCs). However, meta-analysis did not show any statistically significant differences in effect between PDL-derived cells and BMSCs. These results provide important information for the implementation of cell-based approaches in clinical practice as a routine treatment for periodontal regeneration in the future.

Changes in prevalence of periodontitis in two German population-based studies

AIM

We aimed to assess changes of periodontal status in Germany.

MATERIALS & METHODS

The Studies of Health in Pomerania (SHIP) are two cross-sectional population-based studies conducted during 1997-2001 (SHIP-0, 20-81 years, n = 3736) and 2008-2012 (SHIP-Trend, 20-84 years, n = 3622) in northeast Germany. The German Oral Health Studies (DMS, 35-44 and 65-74 years) are national cross-sectional population-based surveys conducted in 1997 (DMS III, n = 1454) and 2005 (DMS IV, n = 1668), whose results were separately reported for West and East Germany. Prevalences, percentages and numbers of teeth affected were defined.

RESULTS

In SHIP, prevalence of attachment loss (AL) ≥ 3 mm decreased from 89.7% (95% confidence interval (CI): 88.6-90.8) to 85.1% (95%CI: 83.9-86.3) (p < 0.05) and the mean extent reduced from 62.8% (95%CI: 61.7-63.8) to 55.9% (95%CI: 54.9-56.9) (p < 0.05). Probing depth (PD) ≥ 4 mm and the respective extent remained unchanged. In West Germany, AL ≥ 3 mm decreased for 35-44-year-olds and increased for 65-74-year-olds (p < 0.05). In SHIP and DMS, the number of teeth in dentates increased significantly in all age groups.

CONCLUSIONS

Prevalences and extents of AL improved almost in all age categories in SHIP and West German adults, whereas PDs remained unchanged. Nonetheless, the improvement of periodontal conditions implies an increase of treatment needs regarding moderately diseased teeth because of simultaneous increases of the number of present teeth.

On putative periodontal pathogens: an epidemiological perspective

The current understanding on the role of microbiology on periodontitis causation is reviewed. An appraisal of the literature reveals several issues that have limited the attempts to investigate candidate periodontal pathogens as causes of periodontitis and confirms that only limited epidemiological evidence is available. Several aspects of the contemporary understanding on causal inference are discussed with examples for periodontitis.