Oral health, atherosclerosis, and cardiovascular disease

Differential roles of tryptophan residues in conformational stability of Porphyromonas gingivalis HmuY hemophore

Background

We have previously shown that the P. gingivalis HmuY hemophore-like protein binds heme and scavenges heme from host hemoproteins to further deliver it to the cognate heme receptor HmuR. The aim of this study was to characterize structural features of HmuY variants in the presence and absence of heme with respect to roles of tryptophan residues in conformational stability.

Results

HmuY possesses tryptophan residues at positions 51 and 73, which are conserved in HmuY homologs present in a variety of bacteria, and a tryptophan residue at position 161, which has been found only in HmuY identified in P. gingivalis strains. We expressed and purified the wildtype HmuY and its protein variants with single tryptophan residues replaced by alanine or tyrosine residues. All HmuY variants were subjected to thermal denaturation and fluorescence spectroscopy analyses. Replacement of the most buried W161 only moderately affects protein stability. The most profound effect of the lack of a large hydrophobic side chain in respect to thermal stability is observed for W73. Also replacement of the W51 exposed on the surface results in the greatest loss of protein stability and even the large aromatic side chain of a tyrosine residue has little potential to substitute this tryptophan residue. Heme binding leads to different exposure of the tryptophan residue at position 51 to the surface of the protein. Differences in structural stability of HmuY variants suggest the change of the tertiary structure of the protein upon heme binding.

Conclusions

Here we demonstrate differential roles of tryptophan residues in the protein conformational stability. We also propose different conformations of apo- and holoHmuY caused by tertiary changes which allow heme binding to the protein.

Association between chronic apical periodontitis and coronary artery disease

INTRODUCTION

Studies have shown that periodontal disease is independently associated with coronary artery disease. However, this same association has not been demonstrated with chronic apical periodontitis. The goal of this study was to establish the relationship between chronic apical periodontitis and coronary artery disease.

METHODS

This cross-sectional study included 103 patients who underwent coronary angiography at the University Hospital Presidente Dutra, Federal University of Maranhão, São Luís-Maranhão, Brazil. The patients answered a structured questionnaire and underwent physical and laboratory examinations. For each patient, a full-mouth set of periapical radiographs was taken. To compare numerical data, Student's t test for independent samples or the Mann-Whitney U test (nonparametric) was used. The homogeneity of variance was assessed by using Levene's test. For comparison of categorical data, the chi-square test or Fisher's exact test was used. The logistic regression analysis was performed to identify the independent predictors of coronary artery disease. The criterion for statistical significance was set at 5%. Statistical analysis was conducted by using SAS version 6.11 software.

RESULTS

The study comprised 103 patients (52 men, 51 women; mean age, 61.9 years); 31.1% were literate, and 55.3% were married. In the study sample, the prevalence of chronic apical periodontitis was 41.7% and of coronary artery disease, it was 65%. The patients with chronic apical periodontitis had a 2.79 times higher risk of developing coronary artery disease.

CONCLUSIONS

In these study patients, chronic apical periodontitis was independently associated with coronary artery disease.

Effects of tobacco on cytokine expression from human endothelial cells

OBJECTIVE

To investigate the effects of nicotine and cigarette smoke condensate (CSC) exposure on cytokine expression from human endothelial cells in order to identify one possible mechanism that smoking plays in the pathogenesis of both periodontal disease (PDD) and cardiovascular disease (CVD).

METHODS

Human endothelial cells (HUVECs) were exposed to different concentrations of nicotine and CSC to examine the effects that they have on cell proliferation and cytotoxicity. Non-toxic levels were then used to examine cytokine expression using cytokine protein arrays.

RESULTS

Exposure to nicotine caused significant down-regulation in the expression of IL-10 (P = 0.046), growth-regulated oncogene (GRO)α (P = 0.036), MCP-1 (P = 0.046), and GMCSF (P = 0.004) compared with the control untreated HUVECs. Exposure to CSC caused significant down-regulation in the expression of GRO (P = 0.04), GROα (P = 0.01), IL-6 (P = 0.03), and MCP-1 (P = 0.04) compared with the control untreated HUVECs.

CONCLUSIONS

Exposure of HUVECs to nicotine or CSC affects the levels of cytokine expression including reduction in anti-inflammatory and chemoattractant cytokines. This may subsequently affect the host defensive mechanisms of the tissues. The action of toxic chemicals in tobacco smoke on endothelial cells is a potential pathogenic mechanism that may in part explain the association between tobacco, PDD, and CVD.

Beta-defensin-2 Genomic Copy Number Variation and Chronic Periodontitis

Chronic periodontitis (ChP) is a multifactorial disease influenced by microbial and host genetic variability; however, the role of beta-defensin-2 genomic ( DEFB4) copy number (CN) variation (V) in ChP remains unknown. The association of the occurrence and severity of ChP and DEFB4 CNV was analyzed. Our study included 227 unrelated Caucasians, that is, 136 ChP patients (combined ChP) and 91 control individuals. The combined ChP group was subdivided into the severe ChP and slight-to-moderate ChP subgroups. To determine DEFB4 CNV, we isolated genomic DNA samples and analyzed them by relative quantitation using the comparative CT method. The serum beta-defensin-2 (hBD-2) level was determined via ELISA. The distribution pattern and mean DEFB4 CN did not differ significantly in combined ChP cases vs. the controls; however, the mean DEFB4 CN in the severe ChP group differed significantly from those for the control and slight-to-moderate ChP groups. Low DEFB4 CN increased the risk of severe ChP by about 3-fold. DEFB4 CN was inversely associated with average attachment loss. Mean serum hBD-2 levels were highest in the controls, followed by the slight-to-moderate ChP group and the severe ChP group. The results suggested an association between decreased DEFB4 CN and serum hBD-2 levels and periodontitis severity.

Prevalence of apical periodontitis and frequency of root canal treatments in liver transplant candidates

Aim: The purpose of this study was to investigate the prevalence of apical periodontitis (AP) and endodontic treatment in liver transplant candidates and control healthy subjects. Material and Methods: A descriptive cross-sectional study. Forty two liver transplant candidates (LTC) (study group) and 42 control subjects. Digital panoramic radiographs where used. Periapical status was scored according to the periapical index (PAI). Results were analysed statistically using the Chi-squared test and logistic regression. Results: Radiographic signs of AP in one or more teeth was found in 79% of patients in the study group and in 50% of control subjects (p = 0.008; OR = 3.7; C. I. 95% = 1.4 - 9.5). One or more root-filled teeth (RFT) were found in 19% and 62% of study and control subjects, respectively (p = 0.0001; OR = 0.14; 95% C. I. = 0.05 - 0.38). Among LTC patients 14.7% of the teeth had AP, whereas in the control subjects 4.2% of teeth were affected (p= 0.0002). The percentage of RFT in the study and control groups was 1.5% and 6.8%, respectively (p = 0.0002). Conclusions: Liver transplant candidates have significantly higher prevalence of radiographic periapical lesions and lower frequency of RFT than controls healthy subjects.

Key words:Apical periodontitis, endodontics, hepatic cirrhosis, liver disease, liver transplant, oral health, root-canal treatment.

Estimate of CRP and TNF-alpha level before and after periodontal therapy in cardiovascular disease patients

INTRODUCTION

Epidemiological studies show that individuals with periodontitis have a radically amplified threat to develop cardiovascular disease. CRP& TNF-α, are acute phase proteins monitored as a marker of inflammatory status, which have been identified as a major risk factor for atherosclerotic complications. Elevated CRP & TNF-α level in periodontitis patients have been reported by several groups. The present study was performed to determine whether presence of periodontitis and periodontal therapy could influence the serum levels of CRP & TNF-α in cardiovascular disease patients.

METHODS

Forty cardiovascular disease subjects participated in the study. They were classified into two groups. Group A (Control) where no periodontal treatment was given, Group B (Test) where periodontal treatment (scaling & root planing) was performed. Periodontal clinical parameters like OHI-S, probing pocket depth, were evaluated together with serum CRP, TNF-α, at baseline and reassessed after 8 weeks for all the subjects in both the groups.

RESULTS

The CRP & TNF-α levels in both the groups decreased but the decrease in the Group A was minimal and was not statistically significant (P > 0.05); whereas in Group B where periodontal therapy was performed, there was statistically significant decrease.

CONCLUSION

It can be concluded from the study that there can be a possible causal relationship between pathogenesis of periodontal disease and CVD as inferred from the statistical significant outcome in the form of decreased inflammatory biomarkers after the periodontal treatment.

Association of oral health and cardiovascular disease risk factors "results from a community based study on 5900 adult subjects"

Objectives. This study aimed to determine the association between some oral health status as a risk factor for cardiac diseases and other cardiovascular disease (CVD) risk factors in a sample of Iranian population in 2011. Methods. The study recruited 5900 inhabitants who aged 15–75 years old of Kerman city through a population based cluster sampling. Having collected informed consent, participants were interviewed for CVD risk factors. Some oral health indicators such as DMFT, Gingival Inflammation index, and Community Periodontal Index were assessed. The association between oral health indices and CVD risk factors was tested using multivariate regression models. Results. The mean age of participants was 33.5 years, and 45.1% were male. Moderate gingival inflammation was observed in 67.6% of participants. Presence of sub- or supragingival calculus was more common (90%) in participants. Older age (RR from 2.7 to 3.88), cigarette smoking (RR = 1.49), and high blood glucose (RR = 1.41) showed an increased risk for oral diseases after adjustment for different covariates including established CVD risk factors. Conclusion. The study results showed an increase in periodontal diseases in the presence of some CVD risk factors. Therefore there may be a bilateral but independent association for both conditions and common risk factor approach preventive program is highly recommended.

The unique hmuY gene sequence as a specific marker of Porphyromonas gingivalis

Porphyromonas gingivalis, a major etiological agent of chronic periodontitis, acquires heme from host hemoproteins using the HmuY hemophore. The aim of this study was to develop a specific P. gingivalis marker based on a hmuY gene sequence. Subgingival samples were collected from 66 patients with chronic periodontitis and 40 healthy subjects and the entire hmuY gene was analyzed in positive samples. Phylogenetic analyses demonstrated that both the amino acid sequence of the HmuY protein and the nucleotide sequence of the hmuY gene are unique among P. gingivalis strains/isolates and show low identity to sequences found in other species (below 50 and 56%, respectively). In agreement with these findings, a set of hmuY gene-based primers and standard/real-time PCR with SYBR Green chemistry allowed us to specifically detect P. gingivalis in patients with chronic periodontitis (77.3%) and healthy subjects (20%), the latter possessing lower number of P. gingivalis cells and total bacterial cells. Isolates from healthy subjects possess the hmuY gene-based nucleotide sequence pattern occurring in W83/W50/A7436 (n = 4), 381/ATCC 33277 (n = 3) or TDC60 (n = 1) strains, whereas those from patients typically have TDC60 (n = 21), W83/W50/A7436 (n = 17) and 381/ATCC 33277 (n = 13) strains. We observed a significant correlation between periodontal index of risk of infectiousness (PIRI) and the presence/absence of P. gingivalis (regardless of the hmuY gene-based sequence pattern of the isolate identified [r = 0.43; P = 0.0002] and considering particular isolate pattern [r = 0.38; P = 0.0012]). In conclusion, we demonstrated that the hmuY gene sequence or its fragments may be used as one of the molecular markers of P. gingivalis.

Oral health problems and mortality

BACKGROUND/PURPOSE

Previous studies have shown the relationship between individual oral health conditions and mortality; however, the relationship between mortality and multiple oral health conditions has not been examined. This study investigates the link between individual oral health problems and oral comorbidity and mortality risk.

MATERIALS AND METHODS

Data are derived from the National Health and Nutrition Examination Survey 1999-2004, which is linked to the National Death Index for mortality follow-up through 2006. We estimated the risk of mortality among people with three individual oral health conditions-tooth loss, root caries, and periodontitis as well as with oral comorbidity-or having all three conditions.

RESULTS

Significant tooth loss, root caries, and periodontal disease were associated with increased odds of dying. The relationship between oral health conditions and mortality disappeared when controlling for sociodemographic, health, and/or health behavioral indicators. Having multiple oral health problems was associated with an even higher rate of mortality.

CONCLUSION

Individual oral health conditions-tooth loss, root caries, and periodontal disease-were not related to mortality when sociodemographic, health, and/or health behavioral factors were considered, and there was no differential pattern between the three conditions. Multiple oral health problems were associated with a higher risk of dying.

The role of physiological markers of health in the association between demographic factors and periodontal disease

BACKGROUND AND OBJECTIVE

Age is highly related to oral health status. The higher prevalence of oral disease within subgroups of the population may reflect a tendency towards "early aging" and dysregulation of multiple physiological systems. This study examines whether the association between periodontal disease and demographic factors is mediated by physiological measures of health.

MATERIAL AND METHODS

Logistic regression was used to examine whether biomarkers and demographic factors, such as socio-economic status (SES) and race/ethnicity, were associated with periodontal disease, and then whether the strength of these relationships could be attributed to associations between demographic variables and physiological measures of systemic health.

RESULTS

Periodontal disease was associated with measures of SES and race/ethnicity. Furthermore, 1-unit increases in cytomegalovirus (CMV), optical density, C-reactive protein (CRP) and glycated hemoglobin (HbA1c) were associated with a 25% [odds ratio (OR) = 1.25; 95% confidence interval (CI): 1.14-1.36], 13% (OR = 1.13; 95% CI = 1.03-1.24) and 19% (OR = 1.19; 95% CI = 1.12-1.27) increased likelihood of periodontal disease, respectively. However, when biomarkers and socio-demographic variables were both included in the model, their associations with periodontal disease were significantly reduced or eliminated.

CONCLUSIONS

The risk of periodontal disease is higher among black and/or low-income individuals; however, these associations appear to be partly due to the greater probability of elevated levels of CRP, CMV or HbA1c among these groups.

Periodontitis in patients with coronary artery disease: an 8-year follow-up

BACKGROUND

This study examines whether preceding assessment of periodontal status in patients with established coronary artery disease (CAD) can predict future CAD endpoints (myocardial infarction, new revascularization procedure, or CAD-related death) during 8-year follow-up and whether the changes in periodontal status over time differ in patients with CAD compared with healthy controls.

METHODS

In 2003, periodontal status was examined in 161 patients with CAD who underwent percutaneous coronary intervention or coronary artery bypass graft due to significant stenosis in the coronary arteries and 162 controls without CAD. Eight years later, 126 patients with CAD (102 males and 24 females, mean age: 68 ± 8.9 years) and 121 controls (101 males and 20 females, mean age: 69 ± 9.0 years) were reexamined periodontally. A standard classification of periodontal disease in three groups (mild, moderate, and severe) was used. CAD endpoints during follow-up were obtained by review of medical records. CAD as cause of death was confirmed from the Swedish Cause of Death Register.

RESULTS

No significant differences were found among patients with CAD, with or without CAD-related endpoints at 8-year follow-up, and severity of periodontitis at baseline (P = 0.7). CAD did not influence the incidence or severity of periodontitis. Significant differences were found at the final examination in periodontitis prevalence and severity (P = 0.001), number of teeth (P = 0.006), probing depth 4 to 6 mm (P = 0.016), bleeding on probing (P = 0.001), and radiographic bone level (P = 0.042) between CAD patients and controls, all in favor of controls.

CONCLUSIONS

The study results did not show a significant association during 8 years among CAD endpoints and periodontal status at baseline. The progression of periodontitis was low in both groups, although the higher proportion of individuals with severe periodontitis among patients with CAD compared with controls remained unchanged over the 8-year follow-up. Further long-term prospective studies are needed to show whether periodontitis can be considered a risk or prognostic factor for CAD, in terms of endpoints including myocardial infarction, new revascularization procedure, and CAD-related death.

Leishmania major Self-Limited Infection Increases Blood Cholesterol and Promotes Atherosclerosis Development

Leishmania major infection of resistant mice causes a self-limited lesion characterized by macrophage activation and a Th1 proinflammatory response. Atherosclerosis is an inflammatory disease involving hypercholesterolemia and macrophage activation. In this study, we evaluated the influence of L. major infection on the development of atherosclerosis using atherosclerosis-susceptible apolipoprotein E-deficient (apoE KO) mice. After 6 weeks of infection, apoE KO mice exhibited reduced footpad swelling and parasitemia similar to C57BL/6 controls, confirming that both strains are resistant to infection with L. major. L. major-infected mice had increased plasma cholesterol levels and reduced triacylglycerols. With regard to atherosclerosis, noninfected mice developed only fatty streak lesions, while the infected mice presented with advanced lesions containing a necrotic core and an abundant inflammatory infiltrate. CD36 expression was increased in the aortic valve of the infected mice, indicating increased macrophage activation. In conclusion, L. major infection, although localized and self-limited in resistant apoE KO mice, has a detrimental effect on the blood lipid profile, increases the inflammatory cell migration to atherosclerotic lesions, and promotes atherogenesis. These effects are consequences of the stimulation of the immune system by L. major, which promotes the inflammatory components of atherosclerosis, which are primarily the parasite-activated macrophages.

Dietary behaviors and oral-systemic health in women

The impact of dietary behaviors and food consumption and their relation to oral health are significant public health issues. Women and men exhibit different dietary behaviors. Understanding the influences of dietary behaviors on oral health from the perspective of gender disparities, however, is limited. This article provides the intersections of dietary factors and oral-systemic health for which women are at greater risk than men. Topics include the effect of dietary choices on oral health disparities seen in female patients. Interventional strategies at the local and community level that are designed to influence the balance between dietary habits and oral-systemic health are discussed.

Periodontal disease and systemic complications

Periodontal diseases comprise a number of infectious and inflammatory conditions brought about by the interaction between supragingival and subgingival biofilms and the host inflammatory response. Periodontal diseases should be considered systemic conditions. This means that they are both modulated by the body's systems and play a role as a risk factor for systemic derangements. The current evidence supports some of these interactions, such as smoking as a risk factor for periodontal disease and diabetes mellitus, as both influenced by and influencing inflammatory changes in the periodontal tissue. Other potential associations are still being researched, such as obesity, hormonal changes, cardiovascular disease, and adverse outcomes in pregnancy. These, and others, still require further investigation before the repercussions of periodontal disease can be fully elucidated. Nevertheless, at the present time, the treatment of periodontal diseases-and, most importantly, their prevention-enables adequate intervention as a means of ensuring periodontal health.

Dental Prophylaxis and Periodontal Treatment Are Protective Factors to Ischemic Stroke

Background and Purpose—

A correlation has been found between periodontal disease (PD) and stroke. This study was conducted to investigate whether dental prophylaxis and periodontal treatment reduce the incidence rate (IR) of ischemic stroke.

Methods—

We identified 510 762 PD cases and 208 674 non-PD subjects from January 1, 2000, to December 31, 2010. The PD cases were divided into dental prophylaxis, intensive treatment, and no treatment groups. The stroke IRs were assessed among groups during follow-up. Cox regression analysis was used after adjustment for age, sex, and comorbidities to determine the relationship between periodontal treatment and incidence of ischemic stroke.

Results—

The stroke IR of the non-PD subjects was 0.32%/year. In the PD group, subjects who received dental prophylaxis had the lowest stroke IR (0.14%/year); subjects with intensive treatment or tooth extraction had a higher stroke IR (0.39%/year); and subjects without PD treatment had the highest stroke IR (0.48%/year; P <0.001). After adjustment for confounders, the dental prophylaxis and intensive treatment groups had a significant lower hazard ratios for stroke than the non-PD group (hazard ratio=0.78 and 0.95; 95% confidence interval=0.75–0.81 and 0.91–0.99, respectively), whereas the PD without treatment group had a significant higher hazard ratio for stroke (1.15; 95% confidence interval=1.07–1.24), especially among the youngest (20–44) age group (hazard ratio=2.17; 95% confidence interval=1.64–2.87) after stratifying for age.

Conclusions—

Maintaining periodontal health by receiving dental prophylaxis and PD treatment can help reduce the incidence of ischemic stroke.

Environmental heme utilization by heme-auxotrophic bacteria

Heme, an iron-containing porphyrin, is the prosthetic group for numerous key cellular enzymatic and regulatory processes. Many bacteria encode the biosynthetic enzymes needed for autonomous heme production. Remarkably, however, numerous other bacteria lack a complete heme biosynthesis pathway, yet encode heme-requiring functions. For such heme-auxotrophic bacteria (HAB), heme or porphyrins must be captured from the environment. Functional studies, aided by genomic analyses, provide insight into the HAB lifestyle, how they acquire and manage heme, and the uses of heme that make it worthwhile, and sometimes necessary, to capture this bioactive molecule.

Simultaneous detection of Streptococcus pneumoniae, S. mitis, and S. oralis by a novel multiplex PCR assay targeting the gyrB gene

A multiplex PCR (mPCR) protocol was developed for simultaneous detection of the gyrB gene in Streptococcus pneumoniae, Streptococcus mitis, and Streptococcus oralis, and the specificity was evaluated using 141 coccus strains. Genomic DNAs purified from S. pneumoniae, S. mitis, and S. oralis strains were efficiently detected with size differences, whereas no PCR products were amplified from any of the reference strains tested. A pilot study of 47 human oral swab specimens was conducted in parallel, and the mPCR assay identified S. pneumoniae in 1 sample, S. mitis in 8 samples, and S. oralis in 2 samples, providing a powerful means for characterization at the level of species compared with traditional culture analysis. Our results suggest that the mPCR protocol presented here is a sensitive and promising tool for the rapid detection and discrimination of S. pneumoniae, S. mitis, and S. oralis from clinical specimens.

Oral hygiene status of individuals with cardiovascular diseases and associated risk factors

Dentist and oral health screening may be the latest weapon in identifying persons at risk of cardiovascular disease. Oral infections, specifically periodontitis, may confer independent risks for different systemic conditions. The risk factors associated with cardiovascular diseases also suggest that the relationship between periodontal disease and diabetes works in both ways. The aim of this study was to support and strengthen the association and relationship between oral hygiene status of individuals with cardiovascular diseases and its associated risk factors. A simple random sampling was carried out in 200 inhabitants of Western Utter Pradesh, India. An oral health visit and examination was made for an equal number of males and females of different age groups with cardiovascular diseases. Evaluation of the oral status was made by means of an oral hygiene index, community periodontal index of treatment needs and loss of attachment. Evaluation of oral status in patients with cardiovascular diseases and in the control group has shown a statistically significant low level of oral health in patients with cardiovascular diseases as compared to control. Prevalence of systemic diseases in different age groups significantly correlated with the prevalence of severe periodontal diseases. Treating gum disease may reduce the risk of heart disease and improve health outcomes for patients with periodontal disease and vascular heart problems.

Prevalence of oral health problems in U.S. adults, NHANES 1999-2004: exploring differences by age, education, and race/ethnicity

Using the National Health and Nutrition Examination Surveys (NHANES) 1999-2004, the authors examined age patterns in oral health indicators by race/ethnicity and socioeconomic status related to edentulism, presence of root caries, and periodontal disease. Our analysis included subjects who were non-Hispanic White, Mexican American, and African American over the age of 20, and who participated in the NHANES oral health examination. African Americans experienced more oral health problems at younger ages; as age increased, so did racial disparities in oral health problems. Lower educational attainment was strongly associated with more oral health problems at all ages. These results may indicate a faster progression of oral health problems with age among African Americans, thus suggesting that the "earlier aging" of members of racial/ethnic minorities which has been reported in prior research may also be found in oral health.

Non-surgical periodontal therapy reduces coronary heart disease risk markers: a randomized controlled trial

AIM

Periodontal disease elevates systemic inflammatory markers strongly associated with coronary heart disease (CHD) risk. The aim of this randomized controlled trial was to investigate the effect of non-surgical periodontal therapy on systemic C-reactive protein (CRP), fibrinogen and white blood cells in CHD patients.

MATERIALS AND METHODS

Angiographically proven CHD patients with periodontitis (n = 317) were randomized to intervention (n = 212) or control group (n = 105). Primary outcome was reduction in serum CRP levels; secondary outcomes were reductions in fibrinogen and white blood cells. Periodontal treatment included scaling, root planing and oral hygiene instructions. Periodontal and systemic parameters were assessed at baseline and at 2-month follow-up. Intent-to-treat (ITT) analysis was performed.

RESULTS

Study was completed by 246 subjects (intervention group = 161; control group = 85). Significant improvements in periodontal and systemic parameters were observed in intervention group. The number of subjects with CRP > 3mg/L in intervention group decreased by 38% and in control group increased by 4%. ITT analysis gave a significant (χ(2) =4.381, p = 0.036) absolute risk reduction of 12.5%.

CONCLUSION

In CHD patients with periodontitis, non-surgical mechanical periodontal therapy significantly reduced systemic levels of C-reactive protein, fibrinogen and white blood cells.

Salivary diagnostics

Saliva is a noninvasive and accessible biofluid that permits early detection of oral and systemic diseases. Recent scientific and technologic advances have uncovered specific salivary biomarkers for a number of clinical conditions, including cancers, autoimmune diseases, and cardiovascular disorders. The availability of highly sensitive and high-throughput assays such as microarray, mass spectrometry, reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) and nano-scale sensors that can measure proteins and nucleic acids are poising saliva as an emerging biofluid for translational and clinical applications. This paper will discuss development of salivary biomarkers for the detection of oral and systemic diseases and the translational application of these markers for clinical applications.

Lack of access in healthcare delivery: a model for using dental hygienists in a cost effective manner to help address the oral healthcare problem

The healthcare delivery of the United States is confronted with many issues and problems. In an attempt to deal with them, the country has been engaged in a process of healthcare reform. Unfortunately, this reform has largely focused on who is going to pay, what is going to be covered, and how all of the constituencies are hopefully going to be satisfied. What have been largely unaddressed are new delivery paradigms or how the care will be distributed to the underserved. The authors attempt to seek solutions to these last two areas of concern. They spell out how the expansion of the scope of practice for dental hygienists will allow them to bridge the gaps in service and to help deliver dental coverage and elements of systemic healthcare to underserved populations. Finally, the authors provide the steps and mechanisms of how the scope of practice can be expanded. Policy and educational requirements are considered.

Porphyromonas gingivalis accelerates neointimal formation after arterial injury

BACKGROUND

Inflammation plays a key role in neointimal hyperplasia after an arterial injury. Chronic infectious disorders, such as periodontitis, are associated with an increased risk of cardiovascular diseases. However, the effects of a periodontal infection on vascular remodeling have not been examined. We assess the hypothesis that periodontal infection could promote neointimal formation after an arterial injury.

METHODS

Mice were implanted with subcutaneous chambers (n = 41). Two weeks after implantation, the femoral arteries were injured, and Porphyromonas gingivalis (n = 21) or phosphate-buffered saline (n = 20) was injected into the chamber. The murine femoral arteries were obtained for the histopathological analysis. The expression level of mRNA in the femoral arteries was analyzed using quantitative reverse transcriptase polymerase chain reaction (n = 19-20).

RESULTS

The intima/media thickness ratio in the P. gingivalis infected group was found to be significantly increased in comparison to the non-infected group. The expression of matrix metalloproteinase-2 mRNA was significantly increased in the P. gingivalis infected group compared to the non-infected group.

CONCLUSION

These findings demonstrate that P. gingivalis injection can promote neointimal formation after an arterial injury. Periodontitis may be a critical factor in the development of restenosis after arterial intervention.

Peripheral arterial disease associated with caries and periodontal disease

BACKGROUND

Peripheral arterial disease (PAD) is an important cardiovascular disorder of the peripheral arteries. Chronic infections, such as periodontitis, may play an important role in the etiology and pathophysiology of PAD and other cardiovascular conditions. Recently, Streptococcus mutans has been found with high frequency in atheromatous plaques. The aim of this study is to evaluate the possible clinical and microbiologic association between PAD and periodontitis and dental caries.

METHODS

Thirty patients with PAD and 30 control individuals were selected. PAD and its severity were established by the use of the ankle-brachial index (ABI). Clinical attachment loss (AL); probing depth; decayed, missing, and filled teeth (DMFT) index; and C-reactive protein (CRP) levels were evaluated. The presence of bacterial DNA from Streptococcus mutans, Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia, Treponema denticola, and Aggregatibacter actinomycetemcomitans was identified by polymerase chain reaction in subgingival biofilm and serum.

RESULTS

Patients with ≥30% AL ≥ 4 mm had six-fold increased risk of having PAD (odds ratio = 8.18; 95% confidence interval = 1.21 to 35.23; P = 0.031). There was statistical difference in the CRP (P = 0.0413) and DMFT index (P = 0.0002), with elevated number of missing teeth (P = 0.0459) in the PAD group compared with the control group. There were no significant differences in the frequency of bacteria in serum and subgingival plaque.

CONCLUSION

There was a positive relationship between periodontitis based on AL and PAD determined by the ABI (odds ratio = 8.18).

[Relationship between periodontitis and systemic diseases]

Periodontitis is a biofilm-induced inflammatory disease affecting the periodontium with a high and even increasing prevalence in the German population. During recent years, there is emerging evidence for systemic effects of a periodontal infection, in particular in relation to diabetes and atherosclerosis. There is a bi-directional relationship between periodontitis and diabetes. Diabetes promotes the occurrence, the progression, and the severity of periodontitis. The periodontal infection complicates the glycemic control in diabetes, increases the risk of diabetes-associated complications and possibly even of its onset. As a consequence, the treatment of periodontal infections should become an integral part of the management of diabetes, whereas glycemic control is a prerequisite for successful periodontal therapy. Periodontal infections are considered as independent risk factor for atherosclerosis and their clinical sequelae, e.g., cerebro- and cardiovascular diseases. The positive association is only moderate, however remarkably consistent. Periodontal therapy can result in positive effects on subclinical markers of atherosclerosis.

Poor oral health and coronary artery disease: a case-control study

BACKGROUND

There is insufficient research on the relationship of oral health and coronary artery disease (CAD) from developing countries, such as Pakistan. This study observes the status of oral health in the CAD population.

METHODS

A case-control study was conducted on 145 cases and 145 controls. Otherwise healthy patients with CAD (cases) and individuals free from previous/current history of CAD (controls), having ≥14 remaining teeth, were examined for oral health status through missing teeth, plaque index (PI), and community periodontal index (CPI). Student t test, χ2 test, and multivariate regression analysis were applied at significance level of 95% (P ≤ 0.05) to compare study parameters between cases and controls.

RESULTS

A significant difference between cases and controls was observed in this study sample with respect to missing teeth (P = 0.027) and periodontal parameters of PI and CPI (P < 0.001). Cases were observed with significantly higher scores of PI (2 and 3) and CPI (3 and 4) compared with controls. Prevalence of periodontal parameters was observed to be higher in cases than controls at subgroup-level (sex and age group) analysis. A significant odds ratio (OR), unadjusted, between CAD and periodontal indicators of PI (mild to severe plaque/no plaque: OR = 5.04, 95% confidence interval [95% CI] = 2.24 to 11.36) and CPI (healthy/poor periodontal status: OR = 4.59, 95% CI = 1.81 to 11.61) scores was noted; cases were at odds of 1.20 (95% CI = 0.93 to 15.68, P = 0.017) for having poor oral health after adjusting age, sex, and education.

CONCLUSION

Poor oral health was significantly associated with CAD in this study sample matched for sociodemographic characteristics.

Both the unique and repeat regions of the Porphyromonas gingivalis hemagglutin A are involved in adhesion and invasion of host cells

Porphyromonas gingivalis is one of the major etiologic agents of adult periodontitis and has been associated with cardiovascular diseases. It expresses multiple hemagglutinins that are significant virulence factors and play an important role in bacterial attachment and invasion of host cells. The objective of this study was to determine the impact of P. gingivalis hemagglutinin A (HagA) on the attachment to and invasion of human coronary artery endothelial cells (HCAEC) and gingival epithelial cells (GEC). Bacterial strains expressing the HagA protein (or subunits), including Escherichia coli carrying plasmid pEKS5, E. coli carrying plasmid ST2, and Salmonella enterica serovar Typhimurium with plasmid pNM1.1 were used in this study. The strains were tested for their ability to attach to and invade HCAEC and GEC using antibiotic protection assays. In addition, the unique 5' N-terminal non-repeated segment of HagA was purified in recombinant form and a monoclonal antibody was created against the polypeptide. The monoclonal antibody against the unique portion of HagA was tested for inhibitory activity in these assays. The attachment of both E. coli strains expressing HagA fragment to host cells was significantly increased compared to their respective controls. However, they did not invade GEC or HCAEC. Interestingly, HagA expression in the Salmonella strain increased both adherence to and invasion of HCAEC, which may be due to the presence of the entire hagA ORF. A monoclonal antibody against the unique 5' N-terminal portion of HagA reduced invasion. Further experiments are needed to determine the role of the unique and the repeat segments of P. gingivalis HagA.

Are lipid profiles true surrogate biomarkers of coronary heart disease in periodontitis patients?: A case-control study in a south Indian population

BACKGROUND

There is abundant literature delving into whether periodontal infection contributes to atherosclerosis. However, whether periodontitis is a definite risk factor for atherosclerosis still remains empirical, with no systematic reviews or longitudinal studies to confirm this hypothesis. The prevalence of periodontitis and coronary artery disease also varies among racial and ethnic groups based on various factors such as diet, lifestyle, and genetic predisposition. This study was designed in a south Indian population with the aim of assessing and correlating the lipid levels (a surrogate biomarker for coronary heart disease) in patients with periodontitis and health.

AIMS

(1) To assess the levels of total cholesterol, low density lipoproteins (LDL), high density lipoproteins (HDL), and triglycerides in periodontal disease, and health in a south Indian population. (2) To assess associations between elevated lipid profiles and periodontal disease.

MATERIALS AND METHODS

This case control study included 60 individuals. Blood sampling for lipid levels and periodontal examination were performed for each study group.

STATISTICAL ANALYSIS

Appropriate statistical tools like Chi-square (P<0.05) and student's "t" test were used. The lipid levels were separately regressed using logistic regression to determine any association with periodontitis cases.

RESULTS

The differences between the mean lipid levels of cases and controls were not statistically significant (P>0.05) after eliminating confounding factors. Odds Ratio=(Total cholesterol (1.005), HDL (0.971), LDL (1.006), VLDL (0.997), CHO-HDL (1.358), TGL (1.007), LDL-HDL (1.180)). The odds ratio stated that there is no significant relation between the lipid levels and periodontal condition. The above findings confirm that there is still no concrete evidence which determines if periodontitis is an independent risk factor for atherosclerotic cardiovascular disease. Future periodontal interventional studies and assessment of genetic markers can ascertain the validity of this hypothesis.

CONCLUSION

There is no association among periodontal disease and the levels of total cholesterol, LDL, HDL, and triglycerides.

Elevation of white blood cells and platelet counts in patients having chronic periodontitis

BACKGROUND AND AIM

Many risk factors that might contribute to the pathogenesis of atherosclerosis have been proposed, including chronic inflammation and infection. Furthermore, systemic inflammatory responses to periodontal bacteria have been suggested as a pathogenetic link between periodontal disease and atherosclerosis. The purpose of this study was to estimate the white blood cell (WBC) and platelet counts in chronic periodontitis patients.

MATERIALS AND METHODS

Fifty patients with chronic periodontitis and 50 patients with healthy periodontium were included in this study. Oral hygiene status, pocket probing depth (PPD) and clinical attachment level (CAL) were measured. During clinical evaluation, venous blood samples were taken to analyze the WBC and platelet counts. Statistical analysis was utilized to compare differences across groups.

RESULTS

Periodontitis patients demonstrated a significantly higher WBC count (7.22 ± 1.42 × 10(9) cells/L) than that of control patients (5.64 ± 1.56 × 10(9) cells/L; P < 0.001). The platelet count of patients with chronic periodontitis (290.73 ± 56.56 × 10(9) cells/L) was also significantly higher compared to the healthy group (223.37 ± 50.27 × 10(9) cells/L; P < 0.001).

CONCLUSION

Levels of WBCs and platelets are elevated in periodontitis patients compared to healthy controls.

Effect of the aetiology and severity of liver disease on oral health and dental treatment prior to transplantation

Elimination of dental infection foci has been recommended before liver transplantation (LT) because lifelong immunosuppression may predispose to infection spread. Association between pre-LT oral health and the aetiology and severity of chronic liver disease (CLD) was investigated retrospectively. A total of 212 adult patients (median age 51.1) who had received LT during 2000-2006 in Finland were included. Their oral health had been pre-operatively examined. Patients were divided into seven different CLD groups. Common indications for LT were primary sclerosing cholangitis (PSC 25.5%), alcohol cirrhosis (ALCI 17.5%) and primary biliary cirrhosis (PBC 14.6%). Patients were also categorized by the Model for End stage Liver Disease (MELD) scoring system. Medical, dental and panoramic jaw x-ray data were analysed between groups. PBC patients had the lowest number of teeth with significant difference to PSC patients (19.7 vs. 25.6, P < 0.005, anova, t-test). ALCI patients had the highest number of tooth extractions with significant difference in comparison to PSC patients (5.6 vs. 2.5, P < 0.005). Lower MELD score resulted in fewer tooth extractions but after adjusting for several confounding factors, age was the most important factor associated with extractions (P < 0.005). The aetiology of CLD associated with the oral health status and there was a tendency towards worse dental health with higher MELD scores.

Prevotella nigrescens and Porphyromonas gingivalis are associated with signs of carotid atherosclerosis in subjects with and without periodontitis

BACKGROUND AND OBJECTIVE

Oral microorganisms may be involved in the development of cardiovascular diseases, and Porphyromonas gingivalis is one of the periodontal microorganisms that has been found in carotid atheroma. The aim of this work was to study subgingival microorganisms and early carotid lesions in subjects with and without periodontitis.

MATERIAL AND METHODS

Eighty-eight subjects with periodontitis and 40 subjects without periodontitis underwent dental examinations in 2003. The presence of the periodontal microorganisms Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia was analyzed from subgingival plaque using PCR amplification. The common carotid artery was scanned using ultrasound and the calculated intima-media area (cIMA) was measured. The association between periodontitis, the cIMA value and the presence of periodontal microorganisms, together with several confounders, was studied in a multiple logistic regression model.

RESULTS

Smoking [odds ratio (OR) = 5.64; p = 0.001), level of education (OR = 5.02; p < 0.05) and the presence of P. gingivalis (OR = 6.50; p < 0.05) were associated with periodontitis. Explanatory factors for the increased cIMA were periodontitis (OR = 4.22; p < 0.05), hypertension (OR = 4.81; p < 0.05), high body mass index (OR = 5.78; p < 0.01), male gender (OR = 3.30; p < 0.05) and poor socioeconomic status (OR = 4.34; p < 0.05). P. nigrescens (OR 4.08; p < 0.05) and P. gingivalis (OR 7.63; p < 0.01) also appeared as explanatory variables associated with increased cIMA values.

CONCLUSION

This cross-sectional study showed that P. nigrescens and P. gingivalis were significantly associated with increased cIMA values.

Iron(III) mesoporphyrin IX and iron(III) deuteroporphyrin IX bind to the Porphyromonas gingivalis HmuY hemophore

Porphyromonas gingivalis acquires heme through an outer-membrane heme transporter HmuR and heme-binding hemophore-like lipoprotein HmuY. Here, we compare binding of iron(III) mesoporphyrin IX (mesoheme) and iron(III) deuteroporphyrin IX (deuteroheme) to HmuY with that of iron(III) protoporphyrin IX (protoheme) and protoporphyrin IX (PPIX) using spectroscopic methods. In contrast to PPIX, mesoheme and deuteroheme enter the HmuY heme cavity and are coordinated by His134 and His166 residues in a fully analogous way to protoheme binding. However, in the case of deuteroheme two forms of HmuY-iron porphyrin complex were observed differing by a 180° rotation of porphyrin about the α-γ-meso-carbon axis. Since the use of porphyrins either as active photosensitizers or in combination with antibiotics may have therapeutic value for controlling bacterial growth in vivo, it is important to compare the binding of heme derivatives to HmuY.

Effect of periodontitis on erectile function and its possible mechanism

INTRODUCTION

Periodontitis is one of the important risk factors resulting in cardiovascular diseases. Erectile dysfunction (ED) is strongly correlated with cardiovascular diseases. The expression of endothelial nitric oxide synthase (eNOS) in penile tissue has an important role in the mechanism of erection.

AIM

To investigate the effect of periodontitis on erectile function and the possible mechanism.

METHODS

After induction of periodontitis in rat, the ratio of maximum intracavernosal pressure/mean arterial pressure (ICPmax /MAP)×100, the expression of eNOS in penile tissue, the level of serum C-reactive protein (CRP) and tumor necrosis factor-α (TNF-α), and the ultrastructural changes of the cavernous tissue were examined and compared between periodontitis rats (group A) and control rats (group B).

MAIN OUTCOME MEASURE

Periodontitis significantly decrease not only the ICPmax/MAP×100 and the expression of eNOS but also the activity of NOS and the level of cyclic guanosine monophosphate (cGMP) in cavernous tissue of rat.

RESULTS

After electrostimulation by 3 and 5 voltage, the ratio of ICPmax /MAP×100 in group A was significantly less than that in group B (19.54±6.16 vs. 30.45±3.12; 30.91±5.61 vs. 50.52±9.52, respectively; P<0.05).The level of serum CRP and TNF-α in group A is significantly higher in group B (P<0.05).The quantitative real-time reverse transcription polymerase chain reaction study demonstrated no statistically significant difference in the expression of mRNA of eNOS in cavernous tissue between the two groups (P>0.05). But there was significant decrease in eNOS protein of the cavernous tissue in group A than in group B (P<0.05). Total NOS activity and cGMP level in cavernosal tissue were significantly lower in group A than in group B (P<0.05). There was no significant alternation occurred in the ultrastructures of penile cavernous tissue.

CONCLUSIONS

The function of penile erection is impaired by periodontitis. The decreased in the expression of eNOS and NOS activity in penile cavernous tissue caused by mild systemic inflammatory status in periodontitis may be one of the important risk factors of ED.

Is periodontal inflammation associated with raised blood pressure? Evidence from a National US survey

There is incomplete and inconclusive evidence for the association between periodontal disease markers and arterial blood pressure, particularly from large national epidemiological studies. This study assessed the relationship between different markers of periodontal inflammation and disease with arterial blood pressure in people aged 17 years and over in USA. We analysed data from the Third National Health and Nutrition Examination Survey on 6617 men and 7377 women who received a periodontal examination. Blood pressure was analysed in both a continuous format and a binary variable for case definition of hypertension. Periodontal disease markers (extent of gingival bleeding, pocket depth, and loss of attachment, and a case definition of periodontitis) were associated on the arterial blood pressure outcomes through a series of regression models, incrementally adjusting for confounders (demographic, inflammation markers, chronic conditions, smoking, BMI, socio-economic status). All periodontal measures had significant crude associations with SBP and hypertension. Gingival bleeding, a marker of current periodontal inflammation, was the only measure consistently and significantly associated with raised SBP and an increased odds of hypertension in the US adult population throughout the adjustment process. For a 10% greater extent of gingival bleeding, the average SBP was higher by 0.5 (0.3, 0.6) mmHg in the fully adjusted model. By referring to the general population and the whole distribution of blood pressure, not only to those at higher risk for hypertension, this association might have some important implications for clinical practice and public health strategies.

Porphyromonas gingivalis participates in pathogenesis of human abdominal aortic aneurysm by neutrophil activation. Proof of concept in rats

Background

Abdominal Aortic Aneurysms (AAAs) represent a particular form of atherothrombosis where neutrophil proteolytic activity plays a major role. We postulated that neutrophil recruitment and activation participating in AAA growth may originate in part from repeated episodes of periodontal bacteremia.

Methods and Findings

Our results show that neutrophil activation in human AAA was associated with Neutrophil Extracellular Trap (NET) formation in the IntraLuminal Thrombus, leading to the release of cell-free DNA. Human AAA samples were shown to contain bacterial DNA with high frequency (11/16), and in particular that of Porphyromonas gingivalis (Pg), the most prevalent pathogen involved in chronic periodontitis, a common form of periodontal disease. Both DNA reflecting the presence of NETs and antibodies to Pg were found to be increased in plasma of patients with AAA. Using a rat model of AAA, we demonstrated that repeated injection of Pg fostered aneurysm development, associated with pathological characteristics similar to those observed in humans, such as the persistence of a neutrophil-rich luminal thrombus, not observed in saline-injected rats in which a healing process was observed.

Conclusions

Thus, the control of periodontal disease may represent a therapeutic target to limit human AAA progression.