Mechanisms involved in the association between periodontal diseases and cardiovascular disease

Interleukin-10 Prevents Pathological Microglia Hyperactivation following Peripheral Endotoxin Challenge

Microglia, the resident macrophages of the brain parenchyma, are key players in central nervous system (CNS) development, homeostasis, and disorders. Distinct brain pathologies seem associated with discrete microglia activation modules. How microglia regain quiescence following challenges remains less understood. Here, we explored the role of the interleukin-10 (IL-10) axis in restoring murine microglia homeostasis following a peripheral endotoxin challenge. Specifically, we show that lipopolysaccharide (LPS)-challenged mice harboring IL-10 receptor-deficient microglia displayed neuronal impairment and succumbed to fatal sickness. Addition of a microglial tumor necrosis factor (TNF) deficiency rescued these animals, suggesting a microglia-based circuit driving pathology. Single cell transcriptome analysis revealed various IL-10 producing immune cells in the CNS, including most prominently Ly49D⁺ NK cells and neutrophils, but not microglia. Collectively, we define kinetics of the microglia response to peripheral endotoxin challenge, including their activation and robust silencing, and highlight the critical role of non-microglial IL-10 in preventing deleterious microglia hyperactivation.

Barriers and Predictors Associated With Accessing Oral Healthcare Among Patients With Cardiovascular Disease in Australia

BACKGROUND

Periodontal disease is associated with cardiovascular disease, and patients should be aware of this risk and seek dental care.

OBJECTIVE

In this study, the authors sought to identify the barriers and predictors for seeking oral healthcare among patients with cardiovascular disease.

METHODS

With the use of a cross-sectional descriptive study design, 307 patients with cardiovascular disease attending cardiac rehabilitation/outpatient cardiac clinics were surveyed between 2016 and 2017 in Sydney, Australia. Survey items included the prevalence of accessing dental services and a new "barriers to seeking frequent dental care" scale.

RESULTS

Most respondents (81%) reported at least 1 oral health problem, yet only 10% received any oral health information and more than half (58%) saw a dentist in the preceding 12 months. The barriers to seeking frequent dental care scale was internally consistent (Cronbach's α = 0.82) with 2 subscales, identified as personal-related and system-related barriers to accessing oral healthcare. Respondents were more likely to have seen a dentist in the previous 12 months if they received oral health information (adjusted odds ratio [AOR], 5.08; 95% confidence interval [CI], 1.62-15.93), had private health insurance (AOR, 3.33; 95% CI, 1.91-5.83), reported low barriers (AOR, 2.68; 95% CI, 1.61-4.47), or were born overseas (AOR, 2.13; 95% CI, 1.25-3.63).

CONCLUSIONS

The accessibility and affordability of dental care, as well as lack of oral health awareness, are key barriers and predictors for patients with cardiovascular disease accessing dental care. Greater emphasis on oral health is needed in the cardiac setting, along with appropriate dental referral pathways.

In Vitro Evaluation of the Antimicrobial and Immunomodulatory Activity of Culinary Herb Essential Oils as Potential Perioceutics

Due to their antimicrobial, immunomodulatory, antioxidant, and regenerative activities, culinary herbs have multiple medicinal uses, among which to prevent and treat oral diseases. The whole essential oils (EOs) have multiple advantages over purified components, such as a low probability to select for antimicrobial resistance, synergic effects of different components, and multi-pharmacological activities. In this study, we aimed to evaluate essential oils from Salvia officinalis (sage), Satureja hortensis (summer savory), and Anethum graveolens (dill) using an in vitro analysis of their antimicrobial activity against Gram-positive and Gram-negative bacterial strains isolated from the oral cavity of patients with periodontitis; the assays addressed both the planktonic and biofilm growth states and used culture-based approaches. Some of the tested EOs exhibited excellent bactericidal and antibiofilm activity, being active at concentrations as low as 0.08-1.36 mg/mL. Flow cytometry was used to investigate the potential mechanisms of their antibacterial activity and confirmed that the tested EOs act by permeabilizing the bacterial membrane and by inhibiting the activity of the efflux pumps. The immunomodulatory effect of the three EOs was determined by analyzing the gene expression profiles for pro- and anti-inflammatory cytokines of the THP-1 cells. The summer savory EO induced a clear proinflammatory effect, while the others did not significantly influence the cytokines profile of the tested cells. Taken together, our results indicate that summer savory EO and, to a lesser extent, sage and dill EOs could be used to inhibit bacteria involved in oral plaque formation and to reduce the expression of genes known to contribute to the inflammatory response using cell culture assessment.

Gallstone Disease and Microbiome

Gallstone disease (GSD) has, for many years, remained a high-cost, socially significant public health problem. Over the past decade, a number of studies have been carried out-both in humans and in animal models-confirming the role of the microbiota in various sections of the gastrointestinal tract as a new link in the etiopathogenesis of GSD. The microbiome of bile correlates with the bacterial composition of saliva, and the microbiome of the biliary tract has a high similarity with the microbiota of the duodenum. Pathogenic microflora of the oral cavity, through mechanisms of immunomodulation, can affect the motility of the gallbladder and the expression of mucin genes (MUC1, Muc3, MUC4), and represent one of the promoters of stone formation in the gallbladder. The presence of H. pylori infection contributes to the formation of gallstones and affects the occurrence of complications of GSD, including acute and chronic cholecystitis, cholangitis, pancreatitis. Intestinal bacteria (Clostridium, Bifidobacterium, Peptostreptococcus, Bacteroides, Eubacterium, and Escherichia coli) participating in the oxidation and epimerization of bile acids can disrupt enterohepatic circulation and lead to the formation of gallstones. At the same time, cholecystectomy due to GSD leads to the further transformation of the composition of the microbiota in various parts of the gastrointestinal tract, increasing the risk of developing stomach cancer and colorectal cancer. Further research is required to determine the possibility of using the evaluation of the composition of the microbiota of the gastrointestinal and biliary tracts as an early diagnostic marker of various gastroenterological diseases.

Melatonin ameliorates periodontitis-related inflammatory stress at cardiac left ventricular tissues in rats

BACKGROUND

The aim of this experimental rat study was to investigate the potential inflammatory effects of periodontitis on cardiac left ventricular tissue and the therapeutic activity of melatonin on these effects.

METHODS

Twenty-four male Sprague-Dawley rats were randomly divided into three groups: control, experimental periodontitis (Ep), and Ep-melatonin (Ep-Mel). Experimental periodontitis was induced by placing and maintaining 3.0 silk ligatures at a peri marginal position on the left and right mandibular first molars for 5 weeks. Afterward, following the removal of ligatures, melatonin (10 mg/body weight) to Ep-Mel group, and vehicle (saline) to Ep and control groups were administered intraperitoneally for 14 days. On the first day of the eighth week, mandibular and cardiac left ventricular tissue samples were obtained following the euthanasia of the rats in all groups. Alveolar bone loss measurements were made on histological and microcomputed tomographic slices. Cardiac tissue levels of malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), matrix metalloproteinase-9 (MMP-9), and cardiac Troponin-T (cTnT) were evaluated by appropriate biochemical methods.

RESULTS

Measurements made on the histological and microcomputed tomographic slices showed that melatonin significantly limits the ligature-induced periodontal tissue destruction (P <0.01). In addition, melatonin was detected to cause a significant decrease of MDA, MMP-9, and cTnT levels which were found to be significantly higher on rats with Ep (P <0.05) while having no significant effect on antioxidant levels (GSH, SOD, and CAT) (P >0.05).

CONCLUSION

Melatonin might be regarded as an important supportive therapeutic agent to reduce the early degenerative changes and possible hypertrophic remodeling at cardiac left ventricular tissues provoked by periodontitis-related bacteria and/or periodontal inflammation.

Breastfeeding may have a long-term effect on oral microbiota: results from the Fin-HIT cohort

BACKGROUND

Breastfeeding contributes to gastrointestinal microbiota colonization in early life, but its long-term impact is inconclusive. We aimed to evaluate whether the type of feeding during the first six months of life was associated with oral microbiota in adolescence.

METHODS

This is a cross-sectional sub-study using baseline information of 423 adolescents from the Finnish Health in Teens (Fin-HIT) cohort. Type of feeding was recalled by parents and dichotomized as (i) No infant formula; (ii) Infant formula (breastmilk + formula or only formula). Saliva microbiota was analysed using 16S rRNA (V3-V4) sequencing. Alpha diversity and beta diversity were compared between feeding type groups using ANCOVA and PERMANOVA, respectively. Differential bacteria abundance was tested using appropriate general linear models.

RESULTS

Mean age and body mass index were 11.7 years and 18.0 kg/m2, respectively. The No formula group contained 41% of the participants. Firmicutes (51.0%), Bacteroidetes (19.1%), and Proteobacteria (16.3%) were the most abundant phyla among all participants. Alpha and beta diversity indices did not differ between the two feeding groups. Three Operational Taxonomic Units (OTUs) belonging to Eubacteria and Veillonella genera (phylum Firmicutes) were more abundant in the No formula than in the Infant formula group (log2fold changes/ p - values - 0.920/ < 0.001, - 0.328/ 0.001, - 0.577/ 0.004).

CONCLUSION

Differences exist in abundances of some OTUs in adolescence according to feeding type during the first six months of life, but our findings do not support diversity and overall oral microbiota composition in adolescents being affected by early feeding type.

Severe and moderate periodontitis are associated with acute myocardial infarction

BACKGROUND

An association between periodontitis and cardiovascular disease is now well documented; however, the effect of periodontitis severity levels on this outcome, specifically on acute myocardial infarction (AMI), remains unexplored. This study investigated the association between levels of periodontitis severity (exposure) and AMI (outcome).

METHODS

This case-control study, matched by sex and age, was conducted with 621 participants, with 207 individuals treated in the emergency department of Santa Izabel and Ana Nery Hospitals in Salvador, Bahia, Brazil, diagnosed with a first AMI event, and compared to 414 individuals without a diagnosis of AMI. Levels of periodontitis severity followed two criteria: (1) Center for Disease Prevention and Control and American Academy of Periodontology; (2) Gomes-Filho et al. (2018) using criteria that also evaluated bleeding upon probing. Conditional logistic regression analysis was performed and odds ratios (ORs) and their 95% confidence intervals (CIs) were obtained.

RESULTS

The adjusted association measurements showed a positive association between both severe (OR_adjusted ranged from 2.21 to 3.92; 95% CI ranged from 1.03 to 10.05) and moderate periodontitis (OR_adjusted ranged from 1.96 to 2.51; 95% CI ranged from 1.02 to 6.19), and AMI, for both periodontitis diagnostic criteria. It demonstrated that among those with moderate and severe periodontitis, the chance of having AMI was approximately two to four times greater than among those without periodontitis.

CONCLUSION

The findings demonstrate that there is an association between the severity of the periodontal condition and AMI, suggesting a possible relationship among the levels of periodontitis severity and the cardiovascular condition.

Impact of Treating Oral Disease on Preventing Vascular Diseases: A Model-Based Cost-effectiveness Analysis of Periodontal Treatment Among Patients With Type 2 Diabetes

OBJECTIVE

Previous randomized trials found that treating periodontitis improved glycemic control in patients with type 2 diabetes (T2D), thus lowering the risks of developing T2D-related microvascular diseases and cardiovascular disease (CVD). Some payers in the U.S. have started covering nonsurgical periodontal treatment for those with chronic conditions, such as diabetes. We sought to identify the cost-effectiveness of expanding periodontal treatment coverage among patients with T2D.

RESEARCH DESIGN AND METHODS

A cost-effectiveness analysis was conducted to estimate lifetime costs and health gains using a stochastic microsimulation model of oral health conditions, T2D, T2D-related microvascular diseases, and CVD of the U.S.

POPULATION

Model parameters were obtained from the nationally representative National Health and Nutrition Examination Survey (NHANES) (2009-2014) and randomized trials of periodontal treatment among patients with T2D.

RESULTS

Expanding periodontal treatment coverage among patients with T2D and periodontitis would be expected to avert tooth loss by 34.1% (95% CI -39.9, -26.5) and microvascular diseases by 20.5% (95% CI -31.2, -9.1), 17.7% (95% CI -32.7, -4.7), and 18.4% (95% CI -34.5, -3.5) for nephropathy, neuropathy, and retinopathy, respectively. Providing periodontal treatment to the target population would be cost saving from a health care perspective at a total net savings of $5,904 (95% CI -6,039, -5,769) with an estimated gain of 0.6 quality-adjusted life years per capita (95% CI 0.5, 0.6).

CONCLUSIONS

Providing nonsurgical periodontal treatment to patients with T2D and periodontitis would be expected to significantly reduce tooth loss and T2D-related microvascular diseases via improved glycemic control. Encouraging patients with T2D and poor oral health conditions to receive periodontal treatment would improve health outcomes and still be cost saving or cost-effective.

The Human Oral Microbiome in Health and Disease: From Sequences to Ecosystems

Abstract: The human oral cavity is home to an abundant and diverse microbial community (i.e., the oral microbiome), whose composition and roles in health and disease have been the focus of intense research in recent years. Thanks to developments in sequencing-based approaches, such as 16S ribosomal RNA metabarcoding, whole metagenome shotgun sequencing, or meta-transcriptomics, we now can efficiently explore the diversity and roles of oral microbes, even if unculturable. Recent sequencing-based studies have charted oral ecosystems and how they change due to lifestyle or disease conditions. As studies progress, there is increasing evidence of an important role of the oral microbiome in diverse health conditions, which are not limited to diseases of the oral cavity. This, in turn, opens new avenues for microbiome-based diagnostics and therapeutics that benefit from the easy accessibility of the oral cavity for microbiome monitoring and manipulation. Yet, many challenges remain ahead. In this review, we survey the main sequencing-based methodologies that are currently used to explore the oral microbiome and highlight major findings enabled by these approaches. Finally, we discuss future prospects in the field.

Pulsed short waves in the remineralization of alveolar bone structures of the jaw in patients with diabetes mellitus – a series of cases

This clinical study included three patients aged between 50 and 78 years who had chronic marginal periodontitis and type 2 diabetes mellitus, diseases that are frequently associated due to changes occurring in polymorphonuclear cells, as well as to alterations of microcirculation. No bone augmentation therapies were performed. Bone regeneration was strictly influenced by conventional periodontal therapy, supplemented with ten pulsed short wave sessions applied to the lower face shortly after closed periodontal curettage. The allocated time was ten minutes for the first two sessions, and 15 minutes for the following 8 sessions. Clinical and radiological evaluations were performed at the time of presentation, as well as after initiation of pulsed short wave therapy: in the first case, three weeks after initiation of therapy and three years after the end of complex oral rehabilitation; in the second case, eight weeks after the onset of pulsed short wave therapy and in the third case, five weeks after the onset of pulsed short wave therapy. The results were significant in all three cases, demonstrated radiologically by the same type of radiological examination at identical scales. Bone remineralization was obvious in the alveolar processes of the jaw. Although further studies in this direction are necessary, the results are both clinically and radiologically significant. Key words: pulsed short waves, alveolar bone resorption, periodontal disease, diabetes,

Apolipoprotein E, periodontal disease and the risk for atherosclerosis: a review

The association between cardiovascular and periodontal diseases is characterized by chronic inflammatory processes, with a high prevalence worldwide and complex genetic-environment interactions. Although apolipoprotein E4 (ApoE4), one of the isoforms coded by a polymorphic APOE gene, has been widely recognized as a risk factor for cardiovascular diseases and as an immunoinflammatory factor, less is known regarding how ApoE4 affects atherosclerosis in periodontitis patients. The aim of this review was to investigate the potential underlying mechanisms related to APOE4 that could increase the risk of periodontal disease and, ultimately, of atherosclerosis. There have only been a few studies addressing apoE polymorphisms in patients with chronic periodontitis. To date, no studies have been performed that have assessed how ApoE4 affects atherosclerotic disease in chronic periodontitis patients. Although clinical studies are warranted, experimental studies have consistently documented the presence of periodontal pathogens, which are usually found in the oral cavity and saliva, in the atherosclerotic plaques of ApoE-deficient mice. In addition, in this review, the potential role of the APOE4 allele as an example of antagonistic pleiotropy during human evolution and its relation to oral health is discussed.

Periodontal, metabolic, and cardiovascular disease: Exploring the role of inflammation and mental health

Previous evidence connects periodontal disease, a modifiable condition affecting a majority of Americans, with metabolic and cardiovascular morbidity and mortality. This review focuses on the likely mediation of these associations by immune activation and their potential interactions with mental illness. Future longitudinal, and ideally interventional studies, should focus on reciprocal interactions and cascading effects, as well as points for effective preventative and therapeutic interventions across diagnostic domains to reduce morbidity, mortality and improve quality of life.

Oral Healthcare and Cardiovascular Disease: A Scoping Review of Current Strategies and Implications for Nurses

BACKGROUND

There is epidemiological evidence showing an association between periodontal disease and cardiovascular disease (CVD). Despite this evidence* no comprehensive review has been undertaken to identify strategies to improve the oral health of people with CVD.

OBJECTIVES

The aim of this review is to identify current evidence relating to the oral healthcare and management of patients with CVD.

METHODS

A scoping review was undertaken focusing on 4 key areas, namely, the impact of periodontal treatment on CVD, current recommendations regarding oral health and CVD, the role of nurses in promoting oral health, and available resources to support them. Databases were searched using a combination of keywords and search terms and 34 articles were selected.

RESULTS

Systematic reviews suggest that periodontal treatment may improve CVD outcomes by reducing systemic inflammation and improving endothelial function. However, there is insufficient evidence to confirm or refute these findings. International guidelines recognize the link between periodontal disease and CVD and recommend preventative strategies in this area. Non-oral health professionals, including nurses, can promote oral health and have been undertaking this role in areas like aged care and pregnancy. However, this aspect of nursing care has not been explored in the cardiac setting and no relevant training and assessment tools are available.

CONCLUSIONS

Maintaining oral health among cardiovascular patients is important, yet it appears to be neglected during cardiac care. Cardiac nurses are in an excellent position to promote oral health but further research is required to define their role and develop supporting resources.

Detection of cytomegalovirus, Epstein-Barr virus, and Torque Teno virus in subgingival and atheromatous plaques of cardiac patients with chronic periodontitis

BACKGROUND

Periodontitis and atherosclerosis represent a chronic inflammatory process. The incidence of periodontitis in cardiac patients with atherosclerosis is a well-established fact. The role of viruses in the etiopathogenesis of both has been proposed.

AIM

The aim of the study was to evaluate the prevalence of Torque Teno virus (TTV), Epstein-Barr virus (EBV), and cytomegalovirus (CMV) in cardiac patients with atherosclerosis and coexisting chronic periodontitis (CP).

MATERIALS AND METHODS

Thirty patients (17 males and 13 females) with atherosclerotic plaques and coexisting periodontitis were recruited for this cross-sectional study. Viral DNA was extracted from the subgingival and atheromatous plaque. The presence of CMV, EBV, and TTV in the plaque samples was identified using polymerase chain reaction. The collected data were statistically analyzed for the prevalence of the viruses and Chi-squared test was performed to find out its association with atheroma and CP.

RESULTS

The prevalence of CMV, EBV, and TTV in atheromatous plaque was 63.3%, 56.7%, and 46.7%, respectively, as compared to rates of 80%, 63.3%, and 53.3% in subgingival plaque. Results also indicated no significant association of CMV, EBV, and TTV in both samples (P = 0.08, 0.346, and 0.261, respectively).

CONCLUSIONS

There was no significant association of CMV, EBV, and TTV between subgingival and atheromatous plaque. The prevalence of CMV, EBV, and TTV was high in atheromatous plaque. TTV was isolated from more than 50% of participants in atheromatous plaque, which is a significant finding.

The oral microbiome and adverse pregnancy outcomes

Significant evidence supports an association between periodontal pathogenic bacteria and preterm birth and preeclampsia. The virulence properties assigned to specific oral pathogenic bacteria, for example, Fusobacterium nucleatum, Porphyromonas gingivalis, Filifactor alocis, Campylobacter rectus, and others, render them as potential collaborators in adverse outcomes of pregnancy. Several pathways have been suggested for this association: 1) hematogenous spread (bacteremia) of periodontal pathogens; 2) hematogenous spread of multiple mediators of inflammation that are generated by the host and/or fetal immune response to pathogenic bacteria; and 3) the possibility of oral microbial pathogen transmission, with subsequent colonization, in the vaginal microbiome resulting from sexual practices. As periodontal disease is, for the most part, preventable, the medical and dental public health communities can address intervention strategies to control oral inflammatory disease, lessen the systemic inflammatory burden, and ultimately reduce the potential for adverse pregnancy outcomes. This article reviews the oral, vaginal, and placental microbiomes, considers their potential impact on preterm labor, and the future research needed to confirm or refute this relationship.

Association between chronic periodontitis and the risk of Alzheimer's disease: a retrospective, population-based, matched-cohort study

Background

Although recent short-term cross-sectional studies have revealed that chronic periodontitis (CP) may be a risk factor for increased cognitive impairment in patients with Alzheimer’s disease (AD), systematic reviews and long-term longitudinal studies have provided less clear evidence regarding the relationship between CP and AD. Therefore, we conducted a retrospective cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan to determine whether patients with CP are at increased risk of developing AD.

Methods

We conducted a retrospective matched-cohort study using the NHIRD of Taiwan. We identified 9291 patients newly diagnosed with CP between 1997 and 2004. A total of 18,672 patients without CP were matched to the patient cohort according to sex, age, index year, co-morbidity and urbanisation level. Cox proportional hazards regression analyses were performed to evaluate the subsequent risk of AD.

Results

Patients with CP had a higher prevalence of hyperlipidaemia, depression, traumatic brain injury and co-morbidities, as well as higher urbanisation levels, than those in the unexposed cohort (all p < 0.01). At the final follow-up, totals of 115 (1.24%) and 208 (1.11%) individuals in the CP exposed and unexposed groups, respectively, had developed AD. Patients with 10 years of CP exposure exhibited a higher risk of developing AD than unexposed groups (adjusted HR 1.707, 95% CI 1.152–2.528, p = 0.0077).

Conclusions

Our findings demonstrate that 10-year CP exposure was associated with a 1.707-fold increase in the risk of developing AD. These findings highlight the need to prevent progression of periodontal disease and promote healthcare service at the national level.

Oral health and cardiovascular care: Perceptions of people with cardiovascular disease

MAIN OBJECTIVE

The aim of this study was to explore the perception of patients with cardiovascular disease towards oral health and the potential for cardiac care clinicians to promote oral health.

METHOD

A needs assessment was undertaken with twelve patients with cardiovascular disease attending cardiac rehabilitation between 2015 and 2016, in three metropolitan hospitals in Sydney, Australia. These patients participated in face-to-face semi-structured interviews. Data was analysed using thematic analysis.

RESULTS

Results suggested that while oral health was considered relevant there was high prevalence of poor oral health among participants, especially those from socioeconomic disadvantaged background. Awareness regarding the importance of oral health care its impact on cardiovascular outcomes was poor among participants. Oral health issues were rarely discussed in the cardiac setting. Main barriers deterring participants from seeking oral health care included lack of awareness, high cost of dental care and difficulties in accessing the public dental service. Findings also revealed that participants were interested in receiving further information about oral health and suggested various mediums for information delivery. The concept of cardiac care clinicians, especially nurses providing education, assessment and referrals to ongoing dental care was well received by participants who felt the post-acute period was the most appropriate time to receive oral health care advice. The issues of oral health training for non-dental clinicians and how to address existing barriers were highlighted by participants.

RELEVANCE TO CLINICAL PRACTICE

The lack of oral health education being provided to patients with cardiovascular disease offers an opportunity to improve care and potentially, outcomes. In view of the evidence linking poor oral health with cardiovascular disease, cardiac care clinicians, especially nurses, should be appropriately trained to promote oral health in their practice. Affordable and accessible dental care services for people with cardiovascular disease should be considered and offered by health services in Australia.

Periodontal disease and women's health

BACKGROUND

Periodontal disease (PD) is a multifactorial inflammatory condition in which inappropriate interaction between the host immune response and specific groups of bacterial pathogens leads to destruction of connective and bone tissues supporting the tooth. Dissemination of pathogens, toxins, and immune complexes from and to periodontal lesions is at the basis of the increasingly recognized association between PD and various systemic diseases (SDs). Considering the growing attention of the medical community to "gender medicine", this review focuses on the association between PD and six systemic conditions heavily impacting women's health, with the aim of providing evidence in support of a joint effort between physicians and dentists to improve clinical management of these conditions.

METHODS

We considered systematic reviews, meta-analyses and narrative reviews evaluating all possible associations between periodontitis, systemic diseases and women.

RESULTS

Gender prevalence for PD is discordant, but the literature strongly supports an association between PD and female infertility and adverse pregnancy outcomes. Moreover, PD is bidirectionally linked to several systemic diseases characterized by an established female gender bias, i.e. osteoporosis (OP), cardiovascular diseases (CVD), autoimmunity, Alzheimer's disease (AD) and cancer.

CONCLUSIONS

Overall, the literature data reviewed here provides a strong foundation for further characterization of molecular and microbial drivers of PD and of several female-prevalent systemic diseases, highlighting the possible importance of a good oral condition in preventing or attenuating women's systemic diseases.

Integrated metagenomic data analysis demonstrates that a loss of diversity in oral microbiota is associated with periodontitis

Background

Periodontitis is an inflammatory disease affecting the tissues supporting teeth (periodontium). Integrative analysis of metagenomic samples from multiple periodontitis studies is a powerful way to examine microbiota diversity and interactions within host oral cavity.

Methods

A total of 43 subjects were recruited to participate in two previous studies profiling the microbial community of human subgingival plaque samples using shotgun metagenomic sequencing. We integrated metagenomic sequence data from those two studies, including six healthy controls, 14 sites representative of stable periodontitis, 16 sites representative of progressing periodontitis, and seven periodontal sites of unknown status. We applied phylogenetic diversity, differential abundance, and network analyses, as well as clustering, to the integrated dataset to compare microbiological community profiles among the different disease states.

Results

We found alpha-diversity, i.e., mean species diversity in sites or habitats at a local scale, to be the single strongest predictor of subjects’ periodontitis status (P < 0.011). More specifically, healthy subjects had the highest alpha-diversity, while subjects with stable sites had the lowest alpha-diversity. From these results, we developed an alpha-diversity logistic model-based naive classifier able to perfectly predict the disease status of the seven subjects with unknown periodontal status (not used in training). Phylogenetic profiling resulted in the discovery of nine marker microbes, and these species are able to differentiate between stable and progressing periodontitis, achieving an accuracy of 94.4%. Finally, we found that the reduction of negatively correlated species is a notable signature of disease progression.

Conclusions

Our results consistently show a strong association between the loss of oral microbiota diversity and the progression of periodontitis, suggesting that metagenomics sequencing and phylogenetic profiling are predictive of early periodontitis, leading to potential therapeutic intervention. Our results also support a keystone pathogen-mediated polymicrobial synergy and dysbiosis (PSD) model to explain the etiology of periodontitis. Apart from P. gingivalis, we identified three additional keystone species potentially mediating the progression of periodontitis progression based on pathogenic characteristics similar to those of known keystone pathogens.

Pregnancy outcome after in utero exposure to local anesthetics as part of dental treatment: A prospective comparative cohort study

BACKGROUND

Dental treatment and use of local anesthetics during pregnancy generally are considered harmless because of lack of evidence of adverse pregnancy effects. Data on the safety of dental treatment and local anesthetics during pregnancy are scant. Dental care is often a reason for concern both among women and their health care providers. The primary objective of this study was to evaluate the rate of major anomalies after exposure to local anesthetics as part of dental care during pregnancy.

METHODS

The authors performed a prospective, comparative observational study at the Israeli Teratology Information Services between 1999 and 2005.

RESULTS

The authors followed 210 pregnancies exposed to dental local anesthetics (112 [53%] in the first trimester) and compared them with 794 pregnancies not exposed to teratogens. The rate of major anomalies was not significantly different between the groups (4.8% versus 3.3%, P = .300). There was no difference in the rate of miscarriages, gestational age at delivery, or birth weight. The most common types of dental treatment were endodontic treatment (43%), tooth extraction (31%), and tooth restoration (21%). Most women (63%) were not exposed to additional medications. Approximately one-half (51%) of the women were not exposed to dental radiography, and 44% were exposed to radiation, mostly bite-wing radiography.

CONCLUSIONS

This study's results suggest that use of dental local anesthetics, as well as dental treatment during pregnancy, do not represent a major teratogenic risk.

PRACTICAL IMPLICATIONS

There seems to be no reason to prevent pregnant women from receiving dental treatment and local anesthetics during pregnancy.

The Helicobacter cinaedi antigen CAIP participates in atherosclerotic inflammation by promoting the differentiation of macrophages in foam cells

Recent studies have shown that certain specific microbial infections participate in atherosclerosis by inducing inflammation and immune reactions, but how the pathogens implicated in this pathology trigger the host responses remains unknown. In this study we show that Helicobacter cinaedi (Hc) is a human pathogen linked to atherosclerosis development since at least 27% of sera from atherosclerotic patients specifically recognize a protein of the Hc proteome, that we named Cinaedi Atherosclerosis Inflammatory Protein (CAIP) (n = 71). CAIP appears to be implicated in this pathology because atheromatous plaques isolated from atherosclerotic patients are enriched in CAIP-specific T cells (10%) which, in turn, we show to drive a Th1 inflammation, an immunopathological response typically associated to atherosclerosis. Recombinant CAIP promotes the differentiation and maintenance of the pro-inflammatory profile of human macrophages and triggers the formation of foam cells, which are a hallmark of atherosclerosis. This study identifies CAIP as a relevant factor in atherosclerosis inflammation linked to Hc infection and suggests that preventing and eradicating Hc infection could reduce the incidence of atherosclerosis.

Linkages between oral commensal bacteria and atherosclerotic plaques in coronary artery disease patients

Coronary artery disease is an inflammatory disorder characterized by narrowing of coronary arteries due to atherosclerotic plaque formation. To date, the accumulated epidemiological evidence supports an association between oral bacterial diseases and coronary artery disease, but has failed to prove a causal link between the two. Due to the recent surge in microbial identification and analyses techniques, a number of bacteria have been independently found in atherosclerotic plaque samples from coronary artery disease patients. In this study, we present meta-analysis from published studies that have independently investigated the presence of bacteria within atherosclerotic plaque samples in coronary artery disease patients. Data were collated from 63 studies covering 1791 patients spread over a decade. Our analysis confirms the presence of 23 oral commensal bacteria, either individually or in co-existence, within atherosclerotic plaques in patients undergoing carotid endarterectomy, catheter-based atherectomy, or similar procedures. Of these 23 bacteria, 5 (Campylobacter rectus, Porphyromonas gingivalis, Porphyromonas endodontalis, Prevotella intermedia, Prevotella nigrescens) are unique to coronary plaques, while the other 18 are additionally present in non-cardiac organs, and associate with over 30 non-cardiac disorders. We have cataloged the wide spectrum of proteins secreted by above atherosclerotic plaque-associated bacteria, and discuss their possible roles during microbial migration via the bloodstream. We also highlight the prevalence of specific poly-microbial communities within atherosclerotic plaques. This work provides a resource whose immediate implication is the necessity to systematically catalog landscapes of atherosclerotic plaque-associated oral commensal bacteria in human patient populations.

A review of bacterial populations in the mouth and in diseased arteries will help research into the role of bacteria in heart disease. Amit Sharma and colleagues at the International Centre for Genetic Engineering and Biotechnology, with co-workers at the All India Institute of Medical Sciences, both in New Delhi, India, analyzed 63 studies covering 1791 patients spread over a decade. They summarize evidence of 23 types of oral bacteria that are also found in atherosclerotic plaques in artery walls. The review also cataloged the proteins secreted by the bacteria and discussed possible involvement of these proteins in the migration of bacteria through the bloodstream. Full genetic details are available for 19 of the 23 bacterial species, which should greatly assist further investigations into the significance of bacteria in the onset of heart disease.

Regulation of matrix metalloproteinase secretion by green tea catechins in a three-dimensional co-culture model of macrophages and gingival fibroblasts

OBJECTIVES

Elevated levels of matrix metalloproteinases (MMPs) have been associated with the active phases of tissue and bone destruction in periodontitis, an inflammatory disease characterized by a significant breakdown of tooth support. In the present study, we used a three-dimensional (3D) co-culture model of macrophages and gingival fibroblasts to investigate the ability of a green tea extract and its major constituent epigallocatechin-3-gallate (EGCG) to regulate the secretion of MMP-3, -8, and -9.

METHODS

The 3D co-culture model was composed of gingival fibroblasts embedded in a type I collagen matrix overlaid with macrophages. Two arbitrary ratios were tested. The ratio composed of 1 macrophage to 10 fibroblasts was used to mimic a slightly inflamed periodontal site while the ratio composed of 10 macrophages to 1 fibroblast was used to mimic a severely inflamed periodontal site. The 3D co-culture model was pre-treated for 2h with either the green tea extract or EGCG. It was then stimulated with Aggregatibacter actinomycetemcomitans lipopolysaccharide (LPS). The model was also first stimulated with LPS for 2h and then incubated with the green tea extract or EGCG. The concentrations of secreted MMP-3, -8, and -9 were quantified by enzyme-linked immunoassays.

RESULTS

When the 3D co-culture model was stimulated with A. actinomycetemcomitans LPS, the 10:1 ratio of macrophages to gingival fibroblasts was associated with a highest secretion of MMP-3 and -9 and, to a lesser extent, MMP-8, than the 1:10 ratio. Non-cytotoxic concentrations of the green tea extract or EGCG reduced the basal secretion levels of all three MMPs. A 2-h treatment with the green tea extract or EGCG prior to the stimulation with LPS resulted in a dose-dependent decrease in MMP secretion, with MMP-9 showing the most significant decrease. A decrease in MMP secretion was also observed when the green tea extract or EGCG was added following a 2-h stimulation with LPS.

CONCLUSIONS

Our results suggested that green tea catechins, and more specifically EGCG, offer promising prospects for the development of a novel adjunctive treatment for periodontitis because of their ability to decrease the secretion of MMPs, which are important tissue-destructive enzymes produced by mucosal and immune cells.

A practical guide to the oral microbiome and its relation to health and disease

The oral microbiome is incredibly complex with the average adult harboring about 50-100 billion bacteria in the oral cavity, which represent about 200 predominant bacterial species. Collectively, there are approximately 700 predominant taxa of which less than one-third still have not yet been grown in vitro. Compared to other body sites, the oral microbiome is unique and readily accessible. There is extensive literature available describing the oral microbiome and discussing the roles that bacteria may play in oral health and disease. However, the purpose of this review is not to rehash these detailed studies but rather to educate the reader with understanding the essence of the oral microbiome, namely that there are abundant bacteria in numbers and types, that there are molecular methods to rapidly determine bacterial associations, that there is site specificity for colonization of the host, that there are specific associations with oral health and disease, that oral bacteria may serve as biomarkers for non-oral diseases, and that oral microbial profiles may have potential use to assess disease risk.

Quantitative Molecular Detection of 19 Major Pathogens in the Interdental Biofilm of Periodontally Healthy Young Adults

In oral health, the interdental spaces are a real ecological niche for which the body has few or no alternative defenses and where the traditional daily methods for control by disrupting biofilm are not adequate. The interdental spaces are the source of many hypotheses regarding their potential associations with and/or causes of cardiovascular disease, diabetes, chronic kidney disease, degenerative disease, and depression. This PCR study is the first to describe the interdental microbiota in healthy adults aged 18–35 years-old with reference to the Socransky complexes. The complexes tended to reflect microbial succession events in developing dental biofilms. Early colonizers included members of the yellow, green, and purple complexes. The orange complex bacteria generally appear after the early colonizers and include many putative periodontal pathogens, such as Fusobacterium nucleatum. The red complex (Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) was considered the climax community and is on the list of putative periodontal pathogens. The 19 major periodontal pathogens tested were expressed at various levels. F. nucleatum was the most abundant species, and the least abundant were Actinomyces viscosus, P. gingivalis, and Aggregatibacter actinomycetemcomitans. The genome counts for Eikenella corrodens, Campylobacter concisus, Campylobacter rectus, T. denticola, and Tannerella forsythensis increased significantly with subject age. The study highlights the observation that bacteria from the yellow complex (Streptococcus spp., S. mitis), the green complex (E. corrodens, Campylobacter gracilis, Capnocytophaga ochracea, Capnocytophaga sputigena, A. actinomycetemcomitans), the purple complex (Veillonella parvula, Actinomyces odontolyticus) and the blue complex (A. viscosus) are correlated. Concerning the orange complex, F. nucleatum is the most abundant species in interdental biofilm. The red complex, which is recognized as the most important pathogen in adult periodontal disease, represents 8.08% of the 19 bacteria analyzed. P. gingivalis was detected in 19% of healthy subjects and represents 0.02% of the interdental biofilm. T. forsythensis and T. denticola (0.02 and 0.04% of the interdental biofilm) were detected in 93 and 49% of healthy subjects, respectively. The effective presence of periodontal pathogens is a strong indicator of the need to develop new methods for disrupting interdental biofilm in daily oral hygiene.

Inflammatory mechanisms linking periodontal diseases to cardiovascular diseases

AIMS

In this article, inflammatory mechanisms that link periodontal diseases to cardiovascular diseases are reviewed.

METHODS

This article is a literature review.

RESULTS

Studies in the literature implicate a number of possible mechanisms that could be responsible for increased inflammatory responses in atheromatous lesions due to periodontal infections. These include increased systemic levels of inflammatory mediators stimulated by bacteria and their products at sites distant from the oral cavity, elevated thrombotic and hemostatic markers that promote a prothrombotic state and inflammation, cross-reactive systemic antibodies that promote inflammation and interact with the atheroma, promotion of dyslipidemia with consequent increases in pro-inflammatory lipid classes and subclasses, and common genetic susceptibility factors present in both disease leading to increased inflammatory responses.

CONCLUSIONS

Such mechanisms may be thought to act in concert to increase systemic inflammation in periodontal disease and to promote or exacerbate atherogenesis. However, proof that the increase in systemic inflammation attributable to periodontitis impacts inflammatory responses during atheroma development, thrombotic events or myocardial infarction or stroke is lacking.

Short-term changes on C-reactive protein (CRP) levels after non-surgical periodontal treatment in systemically healthy individuals

OBJECTIVES

The aim of the present study was to evaluate serum C-reactive protein (CRP) levels in chronic periodontitis patients and periodontally healthy individuals and to assess the effect of non-surgical periodontal treatment on the CRP levels.

MATERIALS AND METHODS

Twenty-two patients with chronic periodontitis (test group) and 22 periodontally healthy individuals (control group), both groups without any systemic disorder or potential confounding factors, were included in the study. At baseline, periodontal clinical variables and CRP levels were obtained in both groups. In the test group, oral hygiene instruction and scaling and root planning were carried out; then, after 60 days, periodontal clinical variables and CRP levels were reevaluated.

RESULTS

The baseline CRP level in the test group was significantly higher than the corresponding value in the control group (1.98 ± 1.55 vs. 1.26 ± 1.05 mg/L; p < 0.05). After periodontal treatment in the test group, there were improvements in all periodontal clinical variables (p < 0.05). The CRP level decreased significantly in those patients with higher baseline levels of CRP (>3 mg/L).

CONCLUSIONS

Chronic periodontitis seemed to promote elevated levels of CRP. Furthermore, non-surgical periodontal treatment significantly decreased the levels of CRP only in patients with high baseline levels of such pro-inflammatory cytokine.

CLINICAL RELEVANCE

Periodontitis may be a potential factor to change the risk of CVD. Thus, the control of periodontal infection performed by health professionals may improve cardiovascular health.

Neutrophil proteolytic activation cascades: a possible mechanistic link between chronic periodontitis and coronary heart disease

Cardiovascular diseases are chronic inflammatory diseases that affect a large segment of society. Coronary heart disease (CHD), the most common cardiovascular disease, progresses over several years and affects millions of people worldwide. Chronic infections may contribute to the systemic inflammation and enhance the risk for CHD. Periodontitis is one of the most common chronic infections that affects up to 50% of the adult population. Under inflammatory conditions the activation of endogenous degradation pathways mediated by immune responses leads to the release of destructive cellular molecules from both resident and immigrant cells. Matrix metalloproteinases (MMPs) and their regulators can activate each other and play an important role in immune response via degrading extracellular matrix components and modulating cytokines and chemokines. The action of MMPs is required for immigrant cell recruitment at the site of inflammation. Stimulated neutrophils represent the major pathogen-fighting immune cells that upregulate expression of several proteinases and oxidative enzymes, which can degrade extracellular matrix components (e.g. MMP-8, MMP-9 and neutrophil elastase). The activity of MMPs is regulated by endogenous inhibitors and/or candidate MMPs (e.g. MMP-7). The balance between MMPs and their inhibitors is thought to mirror the proteolytic burden. Thus, neutrophil-derived biomarkers, including myeloperoxidase, may activate proteolytic destructive cascades that are involved in subsequent immune-pathological events associated with both periodontitis and CHD. Here, we review the existing studies on the contribution of MMPs and their regulators to the infection-related pathology. Also, we discuss the possible proteolytic involvement and role of neutrophil-derived enzymes as an etiological link between chronic periodontitis and CHD.

Microbial composition of atherosclerotic plaques

OBJECTIVE

The association of infections such as periodontitis with atherosclerotic diseases is well documented. In spite of the high diversity of the human oral microbiota, and its close contact with the circulatory system, few oral species were detected in atherosclerotic plaques. Thus, we attempted to evaluate the microbial diversity of atherosclerotic plaques from patients with different periodontal conditions, submitted to endarterectomy by a broad-range microbial method.

MATERIALS AND METHODS

Patients indicated for aorta endarterectomy due to myocardial infarction were recruited for periodontal clinical examination. The microbial diversity of atherosclerotic plaques (n = 35) was evaluated by sequence analysis of bacterial 16S rRNA libraries.

RESULTS

Bacterial DNA was detected in 12 endarterectomy specimens (34.3%). Twenty-three bacterial species/phylotypes were identified. Proteobacteria and Firmicutes comprised 78.3% and 21.7% of the identified taxa, respectively. Fifteen (60.9%) phylotypes were reported as yet uncultivable or as yet uncharacterized species. Two uncultured phylotypes were previously detected in the human mouth. The periodontopathogen Aggregatibacter actinomycetemcomitans was detected in seven samples (20%), followed by Pseudomonas species. There was no association between periodontal parameters and detection of A. actinomycetemcomitans or other phylotypes in atherosclerotic plaques.

CONCLUSION

Our results suggest a role of the oral microbiota in the development of inflammation in atherogenesis, particularly of A. actinomycetemcomitans.

Pathological periodontal pockets are associated with raised diastolic blood pressure in obese adolescents

BACKGROUND

Obesity, a well-known risk factor for developing cardiovascular disease (CVD), is associated with chronic periodontitis in adults. This cross-sectional pilot study on obese adolescents was designed to investigate whether periodontal disease in terms of pathological periodontal pockets is associated with raised blood pressure and other risk markers for CVD.

METHODS

The study included 75 obese subjects between 12 to 18 years of age, mean 14.5. Subjects answered a questionnaire regarding health, oral hygiene habits and sociodemographic factors. A clinical examination included Visible Plaque Index (VPI %), Gingival inflammation (BOP %) and the occurrence of pathological pockets exceeding 4 mm (PD ≥ 4 mm). Blood serum were collected and analyzed. The systolic and diastolic blood pressures were registered.

RESULTS

Adolescents with pathological periodontal pockets (PD ≥ 4 mm; n = 14) had significantly higher BOP >25% (P = 0.002), higher diastolic blood pressure (P = 0.008), higher levels of Interleukin (IL)-6 (P < 0.001), Leptin (P = 0.018), Macrophage Chemoattractant Protein-1 (MCP-1) (P = 0.049) and thyroid stimulating hormone (TSH) (P = 0.004) in blood serum compared with subjects without pathological periodontal pockets (PD ≥ 4 mm; n = 61). The bivariate linear regression analysis demonstrated that PD ≥ 4 mm (P = 0.008) and systolic blood pressure (P < 0.001) were significantly associated with the dependent variable "diastolic blood pressure". The association between PD ≥ 4 mm and diastolic blood pressure remained significant (P = 0.006) even after adjusting for potential confounders BMI-sds, age, gender, mother's country of birth, BOP >25%, IL-6, IL-8, Leptin, MCP-1, TSH and total cholesterol in the multiple regression analysis.

CONCLUSION

In conclusion, this study indicates an association between pathological periodontal pockets and diastolic blood pressure in obese adolescents. The association was unaffected by other risk markers for cardiovascular events or periodontal disease. The results call for collaboration between pediatric dentists and medical physicians in preventing obesity development and its associated disorders.

Danger signaling in atherosclerosis

All aspects of the pathogenesis of atherosclerosis are critically influenced by the inflammatory response in vascular plaques. Research in the field of innate immunity from the past 2 decades has uncovered many novel mechanisms elucidating how immune cells sense microbes, tissue damage, and metabolic derangements. Here, we summarize which triggers of innate immunity appear during atherogenesis and by which pathways they can contribute to inflammation in atherosclerotic plaques. The increased understanding gained from studies assessing how immune activation is associated with the pathogenesis of atherosclerosis has provided many novel targets for potential therapeutic intervention. Excitingly, the concept that inflammation may be the core of cardiovascular disease is currently being clinically evaluated and will probably encourage further studies in this area.

Is periodontitis a risk factor for cognitive impairment and dementia? A case-control study

BACKGROUND

Dementia is a multi-etiologic syndrome characterized by multiple cognitive deficits but not always by the presence of cognitive impairment. Cognitive impairment is associated with multiple non-modifiable risk factors but few modifiable factors. Epidemiologic studies have shown an association between periodontitis, a potentially modifiable risk factor, and cognitive impairment. The objective of this study is to determine whether clinical periodontitis is associated with the diagnosis of cognitive impairment/dementia after controlling for known risk factors, including age, sex, and education level.

METHODS

A case-control study was conducted in Granada, Spain, in two groups of dentate individuals aged >50 years: 1) cases with a firm diagnosis of mild cognitive impairment or dementia of any type or severity and 2) controls with no subjective memory loss complaints and a score >30 in the Phototest cognitive test (screening test for cognitive impairment). Periodontitis was evaluated by measuring tooth loss, plaque and bleeding indexes, probing depths, and clinical attachment loss (AL).

RESULTS

The study included 409 dentate adults, 180 with cognitive impairment and 229 without. A moderate and statistically significant association was observed between AL and cognitive impairment after controlling for age, sex, education level, oral hygiene habits, and hyperlipidemia (P = 0.049). No significant association was found between tooth loss and cognitive impairment.

CONCLUSION

Periodontitis appears to be associated with cognitive impairment after controlling for confounders such as age, sex, and education level.

A systematic review of dental late effects in survivors of childhood cancer

Survivors of childhood cancer are at risk for dental late effects. This systematic review summarizes associations between treatment exposures and dental late effects among survivors of childhood cancer. We included investigations with at least 20 study participants conducted for 2 or more years after completion of childhood, adolescent, or young adult cancer therapy. This review suggests both independent and additive effects of radiotherapy and chemotherapy on dental complications, and identifies vulnerable groups with specific host and treatment characteristics. This summary provides information that will assist clinicians to prevent, detect, and facilitate early intervention for dental late effects.

The influence of the human microbiome and probiotics on cardiovascular health

Cardiovascular disease (CVD) is a major cause of death worldwide. Of the many etiological factors, microorganisms constitute one. From the local impact of the gut microbiota on energy metabolism and obesity, to the distal association of periodontal disease with coronary heart disease, microbes have a significant impact on cardiovascular health. In terms of the ability to modulate or influence the microbes, probiotic applications have been considered. These are live microorganisms which when administered in adequate amounts confer a benefit on the host. While a number of reports have established the beneficial abilities of certain probiotic bacterial strains to reduce cholesterol and hypertension, recent research suggests that their use could be more widely applied. This review presents an up-to-date summary of the known associations of the microbiome with CVD, and potential applications of probiotic therapy.

Tannerella forsythia BspA increases the risk factors for atherosclerosis in ApoE(-/-) mice

OBJECTIVE

The aim of this study was to evaluate the effects of Tannerella forsythia and its major surface virulence factor, BspA, on the progression of atherosclerosis in ApoE(-/-) mice and the expression of lipid metabolism-related genes.

METHODS

PMA-differentiated THP-1 cells were treated with BspA to detect foam cell formation. The proximal aortas of ApoE(-/-) mice injected with T. forsythia or BspA were stained with oil red O to examine lipid deposition. The serum levels of CRP, HDL, and LDL were detected by ELISA. The liver tissue of T. forsythia- or BspA-injected ApoE(-/-) mice was examined for mRNA expression of lipid metabolism-related genes, such as liver X receptors (LXRα and LXRβ) and ATP-binding cassette transporter A1 (ABCA1).

RESULTS

Tannerella forsythia and BspA induced foam cell formation in THP-1 cells and accelerated the progression of atherosclerotic lesions in ApoE(-/-) mice. Mouse serum levels of CRP and LDL were increased, and HDL was decreased by T. forsythia and BspA. The expression levels of LXRα and LXRβ, and ABCA1 in liver tissue were decreased by T. forsythia and BspA.

CONCLUSIONS

Tannerella forsythia and BspA augmented atherosclerotic lesion progression in ApoE(-/-) mice. This process may be associated with downregulation of lipid metabolism-related gene expression.

Are dentists interested in the oral-systemic disease connection? A qualitative study of an online community of 450 practitioners

Background

Dentists in the US see an increasing number of patients with systemic conditions. These patients are challenging to care for when the relationship between oral and systemic disease is not well understood. The prevalence of professional isolation exacerbates the problem due to the difficulty in finding expert advice or peer support. This study aims to identify whether dentists discuss the oral-systemic connection and what aspects they discuss; to understand their perceptions of and attitudes toward the connection; and to determine what information they need to treat patients with systemic conditions.

Methods

We retrieved 14,576 messages posted to the Internet Dental Forum from April 2008 to May 2009. Using natural language processing and human classification, we identified substantive phrases and keywords and used them to retrieve 141messages on the oral-systemic connection. We then conducted coding and thematic analysis to identify recurring themes on the topic.

Results

Dentists discuss a variety of topics on oral diseases and systemic health, with the association between periodontal and systemic diseases, the effect of dental materials or procedures on general health, and the impact of oral-systemic connection on practice behaviors as the leading topics. They also disseminate and share research findings on oral and systemic health with colleagues online. However, dentists are very cautious about the nature of the oral-systemic linkage that may not be causal. Nonetheless, they embrace the positive association as a motivating point for patients in practice. When treating patients with systemic conditions, dentists enquire about the cause of less common dental diseases potentially in relation to medical conditions in one-third of the cases and in half of the cases seek clinical guidelines and evidence-based interventions on treating dental diseases with established association with systemic conditions.

Conclusions

Dentists’ unmet information needs call for more research into the association between less studied dental conditions and systemic diseases, and more actionable clinical guidelines for well-researched disease connections. To improve dissemination and foster behavioral change, it is imperative to understand what information clinicians need and in which situations. Leveraging peer influence via social media could be a useful strategy to achieve the goal.

Anticardiolipin in porphyromonas gingivalis antisera causes fetal loss in mice

β2-glycoprotein I (β2GPI)-dependent anticardiolipin autoantibodies (aCl) are associated with thrombosis and fetal loss. Some microbial pathogens can induce pathogenic antibodies cross-reactive with β2GPI. Sera from a significant percentage of periodontitis patients contain aCl, and some periodontal pathogens contain antigens with peptide sequences having homology to β2GPI. We hypothesized that antibodies raised against P. gingivalis (aPg) contain pathogenic aCl that induce fetal resorption. We immunized mice with β2GPI, P. gingivalis W83, or an arg-gingipain-defective mutant of P. gingivalis (HF18). IgG fractions of aPg were immunoabsorbed to remove aCl-like antibodies (abs-aPg). IgG fractions were administered intravenously into tail veins of mated BALB/c females at day 0 of pregnancy. At day 15, the proportions of fetal resorptions were evaluated. The prevalence of fetal loss was significantly greater in the aPg group than in the control IgG group (21.2% vs. 5.3%, p = .001), and greater in the aPg group than in the abs-aPg group (21.2% vs. 12%, p < .05). There were no fetal resorptions observed in the aPgHF18 group (p = .0005 compared with aPg, p = .17 compared with control). aPg antibody contains activity consistent with pathogenic aCl, and the antigen inducing the antibodies that cause increased fetal loss may be on the arg-gingipain protease of P. gingivalis.

High concentration but low activity of hepatocyte growth factor in periodontitis

BACKGROUND

High levels of hepatocyte growth factor (HGF), a healing factor with regenerative and cytoprotective effects, are associated with inflammatory diseases, including periodontitis. HGF biologic activity requires binding to its receptors, the proto-oncogene c-Met and heparan sulfate proteoglycan (HSPG). This study investigates HGF expression and its relationship to subgingival microbiota in medically healthy individuals with and without periodontitis.

METHODS

Saliva, gingival crevicular fluid (GCF), and blood samples from 30 patients with severe periodontitis and 30 healthy controls were analyzed for HGF concentration using enzyme-linked immunosorbent assay and binding affinity for HSPG and c-Met using surface plasmon resonance. The regenerative effects of saliva from three patients and controls were analyzed in an in vitro model of cell injury. Subgingival plaques were analyzed for the presence of 18 bacterial species.

RESULTS

Patients with periodontitis showed higher HGF concentrations in saliva, GCF, and serum (P <0.001); however, the binding affinities for HSPG and c-Met were reduced in GCF and saliva (P <0.002). In contrast to the controls, saliva from patients showed no significant regenerative effect over time on gingival epithelial cells. Compared with controls, patients had a higher prevalence of periodontally related bacteria.

CONCLUSIONS

Higher circulatory HGF levels indicate a systemic effect of periodontitis. However, the HGF biologic activity at local inflammation sites was reduced, and this effect was associated with the amount of periodontal bacteria. Loss of function of healing factors may be an important mechanism in degenerative processes in periodontally susceptible individuals.