von Willebrand factor antigen and dental infections

Interdental Plaque Microbial Community Changes under In Vitro Violet LED Irradiation

Oral microbiome dysbiosis has important links to human health and disease. Although photodynamic therapy influences microbiome diversity, the specific effect of violet light irradiation remains largely unknown. In this study, we analyzed the effect of violet light-emitting diode (LED) irradiation on interdental plaque microbiota. Interdental plaque was collected from 12 human subjects, exposed to violet LED irradiation, and cultured in a specialized growth medium. Next-generation sequencing of the 16S ribosomal RNA genes revealed that α-diversity decreased, whereas β-diversity exhibited a continuous change with violet LED irradiation doses. In addition, we identified several operational taxonomic units that exhibited significant shifts during violet LED irradiation. Specifically, violet LED irradiation led to a significant reduction in the relative abundance of Fusobacterium species, but a significant increase in several species of oral bacteria, such as Veillonella and Campylobacter. Our study provides an overview of oral plaque microbiota changes under violet LED irradiation, and highlights the potential of this method for adjusting the balance of the oral microbiome without inducing antibiotic resistance.

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.

Three-dimensional measurement of periodontal surface area for quantifying inflammatory burden

Purpose

Measurement of the root surface area (RSA) is important in periodontal treatment and for the evaluation of periodontal disease as a risk factor for systemic disease. The aim of this study was to measure the RSA at 6 mm below the cementoenamel junction (CEJ) using the Mimics software (Materialise, Leuven, Belgium).

Methods

We obtained cone-beam computed tomography (CBCT) data from 33 patients who had visited the Department of Oral and Maxillofacial Radiology of Dankook University Dental Hospital. The patients comprised 17 men and 16 women aged from 20 to 35 years, with a mean age of 24.4 years. Only morphologically intact teeth were included in our data. Because the third molars of the maxilla and mandible have a high deformation rate and were absent in some participants, they were not included in our research material.

Results

The CBCT data were reconstructed into 3-dimensional (3D) teeth models using the Mimics software, and the RSA at 6 mm below the CEJ was separated and measured using 3-Matic (Materialise). In total, 924 3D teeth models were created, and the area at 6 mm below the CEJ could be isolated in all the models. The area at 6 mm below the CEJ was measured in all teeth from the 33 patients and compared based on sex and position (maxilla vs. mandible).

Conclusions

In this study, we demonstrated that it was feasible to generate 3D data and to evaluate RSA values using CBCT and the Mimics software. These results provide deeper insights into the relationship between periodontal inflammatory burden and systemic diseases.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-α, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-a, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Periodontopathogens induce expression of CD40L on human platelets via TLR2 and TLR4

INTRODUCTION

The outstanding importance of (soluble) CD40L to cardiovascular disease (CVD) is becoming increasingly apparent as CD40L is an important mediator of thrombotic and inflammatory processes. Platelets are the main source for CD40 ligand, linking platelet stimulatory events to inflammation and adverse adaptive immune responses. Periodontitis represents a chronic dental infection by distinct gram negative bacteria that is associated with an increased risk for CVD. However, the effects of periodontopathogens on CD40L expression by platelets have not been determined.

MATERIAL AND METHODS

Effects of periodontopathogens A. actinomycetemcomitans Y and P. gingivalis on the expression of CD40L were determined and the underlying receptors and pathways were investigated. 26 patients with periodontitis and 19 controls were included in the clinical part of this study.

RESULTS

Periodontopathogens directly induce surface expression of CD40L in human platelets. This activation depends on plasma factors like CD14 and involves TLR2 and TLR4 but not FcγRII. Inhibition of PI3K and PLC completely abolishes bacteria-induced surface expression of CD40L. TLR2 and TLR4 agonists, for example, are also able to induce expression and release of CD40L in human platelets. In patients with periodontitis, plasma levels of soluble CD40L are elevated and positivity for P. gingivalis is associated with a statistical significant increase of soluble CD40L.

CONCLUSIONS

Our data indicate an involvement of periodontopathogens in increased plasma levels of soluble CD40L in periodontitis and therefore provide a novel link between periodontitis and increased risk for CVD.

Periodontopathogens induce soluble P-selectin release by endothelial cells and platelets

INTRODUCTION

Soluble P-selectin plays a pivotal role in inflammation and the development of thrombotic and cardiovascular disease. Accordingly, elevated levels of soluble P-selectin are found in periodontitis and (other forms of) inflammatory diseases. However, the cellular source of soluble P-selectin in periodontitis and the effects of periodontopathogens on P-selectin release are unknown.

MATERIAL AND METHODS

Soluble P-selectin was determined in 26 patients with periodontitis and 19 controls. Furthermore, human endothelial cells and platelets were investigated for their ability to elicit soluble and surface P-selectin in response to periodontopathogens A. actinomycetemcomitans Y4 and P. gingivalis. Moreover surface E-selectin and ICAM-1 expression as well as NFκB translocation in response to these bacteria were determined on endothelial cells as well as the formation of platelet-leukocyte complexes.

RESULTS

Plasma levels of soluble P-selectin are significantly elevated in periodontitis and correlate with severity of disease and bacterial infection. Stimulation of endothelial cells with periodontopathogens results in rapid surface expression of P-selectin but does not induce NFκB translocation and subsequent de novo synthesis of P-selectin, E-selectin or ICAM-1. In platelets, bacterial stimulation leads to surface expression of P-selectin and fosters the formation of platelet-leukocyte aggregates within minutes. P-selectin is rapidly shed from the surface of platelets and endothelial cells and results in increased levels of soluble P-selectin.

CONCLUSIONS

Periodontopathogens are able to directly cause activation of endothelial cells and platelets within minutes. Given that transient periodontitis-associated bacteremia commonly occurs after tooth brushing or chewing, our data suggest that reduction of periodontopathogens might result in potential cardiovascular benefits.

Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis

BACKGROUND

Periodontal disease is common among adults in the US and is a potential source of chronic inflammation. Recent data have suggested an important role for chronic inflammation in the development of coronary heart disease (CHD).

OBJECTIVE

To aid the United States Preventive Services Task Force (USPSTF) in evaluating whether periodontal disease is an independent novel risk factor for incident CHD.

METHODS

Studies were identified by searching Medline (1966 through March 2008) and reviewing prior systematic reviews, reference lists, and consulting experts. Prospective cohort studies that assessed periodontal disease, Framingham risk factors, and coronary heart disease incidence in the general adult population without known CHD were reviewed and quality rated using criteria developed by the USPSTF. Meta-analysis of good and fair quality studies was conducted to determine summary estimates of the risk of CHD events associated with various categories of periodontal disease.

RESULTS

We identified seven articles of good or fair quality from seven cohorts. Several studies found periodontal disease to be independently associated with increased risk of CHD. Summary relative risk estimates for different categories of periodontal disease (including periodontitis, tooth loss, gingivitis, and bone loss) ranged from 1.24 (95% CI 1.01-1.51) to 1.34 (95% CI 1.10-1.63). Risk estimates were similar in subgroup analyses by gender, outcome, study quality, and method of periodontal disease assessment.

CONCLUSION

Periodontal disease is a risk factor or marker for CHD that is independent of traditional CHD risk factors, including socioeconomic status. Further research in this important area of public health is warranted.

Systemic effects of periodontitis: epidemiology of periodontal disease and cardiovascular disease

There have been 42 published studies describing associations between oral conditions and cardiovascular diseases. In the absence of randomized controlled trials, the 16 longitudinal studies represent the highest level of evidence available. However, two databases produced eight of the 16 studies. There also is extensive variability in definitions of the oral exposure that include salivary flow, reported periodontal disease, number of teeth, oral organisms, antibodies to oral organisms, Total Dental Index, Community Periodontal Index of Treatment Needs, plaque scores, probing depth, attachment loss, and bone level. Variability also exists in the cardiovascular outcomes that include atherosclerosis measures and events, such as hospitalization for coronary heart disease (CHD), chronic CHD, fatal CHD, total stroke, ischemic stroke, and revascularization procedures. One of the criticisms of this research is that the exposure has not been represented by measures of infection. To begin to address this concern, we present new data showing that patterns of high and low levels of eight periodontal pathogens and antibody levels against those organisms are related to clinical periodontal disease as well as other characteristics of the individuals, such as age, race, gender, diabetic status, atherosclerosis, and CHD. As others before us, we conclude that the cumulative evidence presented above supports, but does not prove, a causal association between periodontal infection and atherosclerotic cardiovascular disease or its sequelae. A number of legitimate concerns have arisen about the nature of the relationship and, indeed, the appropriate definitions for periodontal disease when it is thought to be an exposure for systemic diseases. There is still much work needed to identify which aspects of the exposure are related to which aspects of the outcome. Principal component analyses illustrate the complexity of the interactions among risk factors, exposures, and outcomes. These analyses provide an initial clustering that describes and suggests the presence of specific syndromes.

Periodontal disease and coronary heart disease: a reappraisal of the exposure

BACKGROUND

Results from studies relating periodontal disease to cardiovascular disease have been mixed. Residual confounding by smoking and use of clinical measures of periodontal disease rather than measures of infection have been 2 major criticisms. The aims of this study were to investigate relationships between prevalent coronary heart disease (CHD) and 2 exposures, (1) clinical periodontal disease and (2) IgG antibodies to 17 oral organisms, and to evaluate the role of smoking in these relationships.

METHODS AND RESULTS

Our study is based on a subset of participants in the Atherosclerosis Risk in Communities (ARIC) Study, who received a complete periodontal examination during visit 4 (1996-1998). The exposures were periodontal status and serum IgG antibody levels against 17 periodontal organisms, and the outcome was prevalent CHD at visit 4. Multivariable analyses indicate that periodontal status is not significantly associated with CHD in either ever smokers or never smokers. Similar analyses evaluating antibodies indicate that high antibodies (above the median) to Treponema denticola (odds ratio [OR]=1.7; 95% CI, 1.2 to 2.3), Prevotella intermedia (OR=1.5; 95% CI, 1.1 to 2.0), Capnocytophaga ochracea (OR=1.5; 95% CI, 1.1 to 2.1), and Veillonella parvula (OR=1.7; 95% CI, 1.2 to 2.3) are significantly associated with CHD among ever smokers, whereas Prevotella nigrescens (OR=1.7; 95% CI, 1.1 to 2.6), Actinobacillus actinomycetemcomitans (OR=1.7; 95% CI, 1.2 to 2.7), and Capnocytophaga ochracea (OR=2.0; 95% CI, 1.3 to 3.0) were associated with CHD among never smokers.

CONCLUSIONS

Clinical signs of periodontal disease were not associated with CHD, whereas systemic antibody response was associated with CHD in ever smokers and never smokers. These findings indicate that the quality and quantity of the host response to oral bacteria may be an exposure more relevant to systemic atherothrombotic coronary events than clinical measures.

Persistent infection and vascular disease: a systematic review

More than 150 epidemiological or clinical studies have reported on associations between vascular disease and the presence of certain persistent bacterial and viral agents, or of clinical conditions (e.g., periodontal disease) that are associated with persistent infection. This article provides a review of such studies, particularly in relation to Helicobacter pylori, Chlamydia pneumoniae, dental disease and cytomegalovirus (CMV), as well as references to possible mechanisms. The association between coronary heart disease and H. pylori or between heart disease and dental disease may be accounted for by residual confounding. Although markers of C. pneumoniae infection are around twenty times more common in atherosclerotic plaques than in disease-free blood vessels, the sequence of infection and disease is uncertain. For CMV, a limited number of patients with classic atherosclerotic coronary heart disease have been investigated in seroepidemiological studies. For all such agents, better and larger seroepidemiological and pathology-based studies are needed to resolve these uncertainties, as well as - at some stage - large-scale, randomised intervention studies.

A Pilot Study Into Measurements of Markers of Atherosclerosis in Periodontitis

BACKGROUND

Periodontitis may be a possible risk factor for atherosclerosis. The current pilot study explored arterial wall thickness and other variables associated with atherosclerosis in healthy subjects with and without periodontitis.

METHODS

Patients with moderate (N = 34) and severe periodontitis (N = 15) and controls (N = 14) were recruited. Intima media thickness (IMT) of the common carotid arteries (CCA), internal carotid arteries (ICA), and bifurcations of carotid arteries (BCA) was estimated bilaterally using B-mode ultrasound. An overall IMT was calculated as the mean of these six measurements. C reactive protein (CRP), fibrinogen, and von Willebrand factor (vWf) were measured in plasma as indicators of systemic inflammation and atherosclerotic disease. Microalbuminuria was determined as a marker of endothelial cell dysfunction.

RESULTS

IMT for CCA were 0.64, 0.68, and 0.69 mm for control, moderate, and severe periodontitis, respectively (not significant). IMT for BCA did not vary among groups. IMT of ICA was largest for severe periodontitis (0.81 mm); corresponding values for controls and moderate periodontitis were 0.58 and 0.55 mm, respectively (P= 0.023). Severe periodontitis patients had an overall IMT of 0.76 mm, while moderate periodontitis patients and controls had lower values (0.64 and 0.65 mm, respectively; P= 0.153). After adjusting for potential confounding factors, the increased IMT for ICA in severe periodontitis was also significant (Padj = 0.040). CRP (P= 0.020, Padj = 0.050) and vWf (P= 0.019, Padj = 0.013) were higher in periodontitis than controls; microalbuminuria was not different between groups. Power calculations suggest that a 4-fold expansion of the severe patient and control groups will result in a high chance (power level 80%) that a clinically significant association between the overall IMT and periodontitis will be observed.

CONCLUSION

The present pilot study indicates that a full study investigating the relationship between periodontitis and atherosclerosis is warranted.

Oral health, atherosclerosis, and cardiovascular disease

During the last two decades, there has been an increasing interest in the impact of oral health on atherosclerosis and subsequent cardiovascular disease (CVD). The advent of the inflammation paradigm in coronary pathogenesis stimulated research in chronic infections caused by a variety of micro-organisms-such as Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus-as well as dental pathogens, since these chronic infections are thought to be involved in the etiopathogenesis of CVD by releasing cytokines and other pro-inflammatory mediators (e.g., C-reactive protein [CRP], tumor necrosis factor [TNF-alpha]) that may initiate a cascade of biochemical reactions and cause endothelial damage and facilitate cholesterol plaque attachment. Yet, due to the multi-factorial nature of dental infection and CVD, confirming a causal association is difficult, and the published results are conflicting. The main deficit in the majority of these studies has been the inadequate control of numerous confounding factors, leading to an overestimation and the imprecise measurement of the predictor or overadjustment of the confounding variables, resulting in underestimation of the risks. A meta-analysis of prospective and retrospective follow-up studies has shown that periodontal disease may increase the risk of CVD by approximately 20% (95% confidence interval [CI], 1.08-1.32). Similarly, the reported risk ratio between periodontal disease and stroke is even stronger, varying from 2.85 (CI 1.78-4.56) to 1.74 (CI 1.08-2.81). The association between peripheral vascular disease and oral health parameters has been explored in only two studies, and the resultant relative risks among individuals with periodontitis were 1.41 (CI 1.12-1.77) and 2.27 (CI 1.32-3.90), respectively. Overall, it appears that periodontal disease may indeed contribute to the pathogenesis of cardiovascular disease, although the statistical effect size is small.

Periodontal disease and biomarkers related to cardiovascular disease

Periodontal disease is a chronic infection of the gums characterized by a loss of attachment between the tooth and bone, and by bone loss. We evaluated cross-sectionally the association between periodontal disease and C-reactive protein (CRP), fibrinogen, factor VII, tissue plasminogen activator (t-PA), LDL-C, von Willebrand factor, and soluble tumor necrosis factor receptors 1 and 2. The final sample consisted of 468 men (ages 47-80 yrs), participating in the Health Professional Follow-up Study, who provided blood and were free of CVD, diabetes, and cancer. In multivariate regression models controlling for age, cigarette smoking, alcohol intake, physical activity, and aspirin intake, self-reported periodontal disease was associated with significantly higher levels of CRP (30% higher among periodontal cases compared with non-cases), t-PA (11% higher), and LDL-C (11% higher). Based on our data, periodontal disease showed significant associations with biomarkers of endothelial dysfunction and dyslipidemia, which may potentially mediate the association between periodontal and cardiovascular disease.

[Odontogenic foci--possible etiology of urticaria?]

Recent studies have shown that chronic odontogenic infections could pose a risk for myocardial infarction, cerebral ischemia, and arteriosclerosis. However, the correlation between urticaria and dental infections has rarely been examined so far. Therefore, we performed a case-control study using a standardized questionnaire and examination. We investigated 66 patients suffering from an acute or chronic urticaria and 65 age- and sex-matched healthy patients as a control group. Dental status was determined by a so-called total dental index (TDI) which primarily reflects caries, periodontitis, periapical lesions, and nonvital and missing teeth. All 66 patients were referred from the department of dermatology. After their treatment in hospital, all patients received a questionnaire with questions on intensity and localization of the urticaria. The TDI of the urticaria patients was slightly better ( n=66; 2.6+/-1.98) than that of the control group ( n=65, TDI=3.3+/-1.86). Subsequently, it was determined if the urticaria had receded after dental treatment. In conclusion, chronic dental infections do not seem to correlate with an increased risk for urticaria.

Immunoglobulin G profiles in different forms of periodontitis

BACKGROUND

Races and Gm(23) allotypes can modify the serum levels of IgG subclasses. The average serum levels of IgG subclasses of African-Americans have been reported to be higher than those of Caucasians in both healthy young adults and patients with aggressive periodontitis; Gm(23)-positive subjects generally had higher IgG2 levels than Gm(23)-negative subjects.

OBJECTIVE

We examined serum immunoglobulin G (IgG) concentrations in Taiwanese patients with different forms of periodontitis.

METHODS

The serum levels of four IgG subclasses were determined by enzyme-linked immunosorbent assay and Gm(23) allotypes were verified by radial immunodiffusion tests in 50 patients with chronic periodontitis, 30 patients with aggressive periodontitis, and 74 healthy controls.

RESULTS

There were no differences in the concentrations of four IgG subclasses in patients with chronic periodontitis compared with age-matched controls. However, in subjects younger than 35 years, levels of IgG2 were significantly elevated in patients with aggressive periodontitis compared with controls. We also found significant differences in IgG2 levels within the control group when stratified by age (< or = 35 years and > 35 years). Gm(23) allotypes were not correlated with the serum levels of IgG2 in either patient group.

CONCLUSION

Microbial challenge might not provoke significant changes in systemic IgG response in patients with chronic periodontitis. However, in patients with aggressive periodontitis, IgG2 levels were increased when compared with age-matched controls. Gm(23) allotypes had no influence on IgG2 levels in well-established generalized chronic periodontitis or aggressive periodontitis.

Meta-analysis of periodontal disease and risk of coronary heart disease and stroke

OBJECTIVE

The purpose of this study was to analyze published studies and abstracts in order to provide a quantitative summary of periodontal disease as a risk factor for cardiovascular disease and to explore the possible causes for conflicting results in the literature.

STUDY DESIGN

We searched all published literature on the Medline literature search engine since 1980. An additional search was performed with bibliographic citations from each article. Nine cohort studies (8 prospective and 1 retrospective), in which relative risks (RRs), CIs, and P values were reported or could be calculated were included. Four researchers independently extracted RRs, CIs, and P values from each study and evaluated the degree of confounding adjustment. The combined result was calculated with weighted average, and sources of disparity were tested with regression analyses.

RESULTS

The summary RR was 1.19 (95% CI, 1.08 1.32), indicating a higher risk of future cardiovascular events in individuals with periodontal disease compared with those without. In an analysis stratified to individuals of </=65 years of age, the RR was 1.44 (95% CI, 1.20 to 1.73). When the outcome was restricted to stroke only, the RR was 2.85 (95% CI, 1.78 to 4.56). In the metaregression analysis, the effects of residual confounding caused an overestimate of the results by 12.9% and, with a proxy for periodontal disease, caused an underestimate of 29.7%.

CONCLUSIONS

Periodontal disease appears to be associated with a 19% increase in risk of future cardiovascular disease. This increase in RR is more prominent (44%) in persons aged </=65 years. Although the increment of risk between subjects with or without periodontal disease in the general population is modest, at around 20% because nearly 40% of population has periodontal disease, this modest increase may have a profound public health impact.

Cardiovascular diseases and periodontology

BACKGROUND

Cardiovascular diseases represent a widespread heterogeneous group of conditions that have significant morbidity and mortality. The various diseases and their treatments can have an impact upon the periodontium and the delivery of periodontal care.

AIM

In this paper we consider three main topics and explore their relationship to the periodontist and the provision of periodontal treatment.

METHOD

The areas reviewed include the effect of cardiovascular drugs on the periodontium and management of patients with periodontal diseases; the risk of infective endocarditis arising from periodontal procedures; the inter-relationship between periodontal disease and coronary artery disease.

RESULTS AND CONCLUSIONS

Calcium-channel blockers and beta-adrenoceptor blockers cause gingival overgrowth and tooth demineralisation, respectively. Evidence suggests that stopping anticoagulant therapy prior to periodontal procedures is putting patients at a greater risk of thromboembolic disorders compared to the risk of prolonged bleeding. The relationship between dentistry and infective endocarditis remains a controversial issue. It would appear that spontaneous bacteraemia arising from a patient's oral hygiene practices is more likely to be the cause of endocarditis than one-off periodontal procedures. The efficacy of antibiotic prophylaxis is uncertain (and unlikely to be proven), and the risk of death from penicillin appears to be greater than the risk of death arising from infective endocarditis. Finally, the association between periodontal disease and coronary artery disease has been explored and there seem to be many issues with respect to data handling interpretation. Many putative mechanisms have been suggested; however, these only further highlight the need for intervention studies.

Relationships Among Clinical Measures of Periodontal Disease and Their Associations With Systemic Markers

BACKGROUND

Recent investigations of the relationship between periodontitis and systemic disease require that periodontal disease also must be thought of as a disease process that is an exposure for a systemic disease or condition (outcome), rather than as the outcome itself. When viewing periodontal disease as an exposure, investigators must consider the clinical, microbiological, and inflammatory components of periodontitis that potentially convey risk for the systemic outcome of interest, which may or may not be the same as those associated with the assessments used to define tooth-based disease. Another important consideration is the temporal relationship between the exposure and the outcome of interest.

METHODS

To explore which definitions of periodontal disease or clustering of clinical signs are important with regards to systemic exposure to inflammatory stress, we examined the relationship between clinical periodontal disease measures and 2 systemic inflammatory markers of increased risk for cardiovascular disease: serum soluble intercellular adhesion molecule (sICAM), which is a measure of vascular stress and serum C-reactive protein (CRP), which is a measure of hepatic acute-phase response. The Dental Arteriosclerosis Risk in Communities (ARIC) study, a cross-sectional study of the relationship between periodontal disease and cardiovascular disease, forms the basis for the examples used in this investigation.

RESULTS

Our findings demonstrated that while attachment loss, probing depth, (PD) and bleeding on probing (BOP) are individually associated with sICAM and CRP, only BOP remains significant for sICAM when all 3 are in the model and, for CRP, only PD remains significant. Both of these clinical parameters were more robust in estimating the degree of systemic inflammation than traditional classifications of mild, moderate, and severe periodontitis or other measures of disease severity such as attachment loss.

CONCLUSIONS

When selecting a definition of "systemic periodontitis" (periodontal disease that represents an exposure for a systemic condition), it is helpful to think of periodontal disease as a chronic oral infection with a number of clinical signs, rather than as the dento-centrically defined entity, periodontal disease. Thus, "systemic periodontitis" should be defined predicated upon those clinical signs that best represent the underlying mechanisms and temporal sequence that may affect that systemic outcome.

Periodontal disease and cardiovascular disease: epidemiology and possible mechanisms

BACKGROUND

Many early epidemiologic studies reported an association between periodontal disease and cardiovascular disease. However, other studies found no association or nonsignificant trends. This report summarizes the evidence from epidemiologic studies and studies that focused on potential contributing mechanisms to provide a more complete picture of the association between periodontal and heart disease.

TYPES OF STUDIES REVIEWED

The authors summarize the longitudinal studies reported to date, because they represent the highest level of evidence available regarding the connection between periodontal disease and heart disease. The authors also review many of the case-control and cross-sectional studies published, as well as findings from clinical, animal and basic laboratory studies.

RESULTS

The evidence suggests a moderate association--but not a causal relationship--between periodontal disease and heart disease. Results of some case-control studies indicate that subgingival periodontal pathogenic infection may be associated with myocardial infarction. Basic laboratory studies point to the biological plausibility of this association, since oral bacteria have been found in carotid atheromas and some oral bacteria may be associated with platelet aggregation, an event important for thrombosis. Animal studies have shown that atheroma formation can be enhanced by exposure to periodontal pathogens.

CONCLUSIONS

The accumulation of epidemiologic, in vitro, clinical and animal evidence suggests that periodontal infection may be a contributing risk factor for heart disease. However, legitimate concerns have arisen about the nature of this relationship. These are early investigations. Since even a moderate risk contributed by periodontal disease to heart disease could contribute to significant morbidity and mortality, it is imperative that further studies be conducted to evaluate this relationship. One particularly important study to be carried out is the investigation of a possible clinically meaningful reduction in heart disease resulting from the prevention or treatment of periodontal disease.

Chronic infections and atherosclerosis/thrombosis

An emerging pathophysiologic paradigm implicates chronic inflammation in the initiation, progression, and destabilization of atherosclerotic vascular disease. Various potential contributors to the inflammatory response in the vessel wall include atherogenic lipids, mechanical stress and injury, hypertension and angiotensin II, cigarette smoking, immune response to neoantigens, and chronic infections with viruses and or bacteria (Table 1). The potential link between chronic infection and atherosclerosis/thrombosis is under extensive investigation in several laboratories around the world. Although indirect evidence and experimental data tend to support this link, definitive proof is still lacking. If such a link is eventually proven to be causal in nature, it will provide a novel target for preventive and therapeutic strategies (anti-infective drugs, vaccines, etc.) against a common disease that is the leading killer of people in Western nations. Results of ongoing, large-scale clinical trials are eagerly awaited.

General health risk of periodontal disease

The possibility that periodontal disease might influence the morbidity and mortality of systemic diseases constitutes a research topic of great current interest. Human periodontal disease is associated with a complex microbiota containing approximately 500 microbial taxa and various human viruses, many of which possess significant virulence potential. Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis and other periodontopathic bacteria that are unique to the oral cavity and may disseminate to other body sites comprise the best-documented form of dental focal infection. However, systemically healthy individuals seem to be at low risk of acquiring acute non-oral diseases from direct infections by periodontal pathogens. Research data from various laboratories point to periodontal infections as a risk factor for chronic medical disorders, including cardiovascular disease, cerebrovascular accidents and low-birth-weight infants. However, recent epidemiological studies have failed to show a significant relationship between periodontal disease and cardiovascular disease. This review paper evaluates the current status of knowledge on dental focal infection and suggests avenues for further research into the topic of general health risks of periodontal disease.

Treatment of periodontitis by local administration of minocycline microspheres: a controlled trial

BACKGROUND

Periodontitis is an inflammatory condition of tooth-supporting tissues that is usually treated by mechanical removal of plaque and microorganisms that adhere to teeth. This treatment, known as scaling and root planing, is not optimally effective. Adjunctive therapy with locally delivered antimicrobials has resulted in improved clinical outcomes such as probing depth reduction. This article reports on the efficacy and safety of locally administered microencapsulated minocycline.

METHODS

Seven hundred forty-eight (748) patients with moderate to advanced periodontitis were enrolled in a multi-center trial and randomized to 1 of 3 treatment arms: 1) scaling and root planing (SRP) alone; 2) SRP plus vehicle; or 3) SRP plus minocycline microspheres. The primary outcome measure was probing depth reduction at 9 months. Clinical assessments were performed at baseline and 1, 3, 6, and 9 months.

RESULTS

Minocycline microspheres plus scaling and root planing provided substantially more probing depth reduction than either SRP alone or SRP plus vehicle. The difference reached statistical significance after the first month and was maintained throughout the trial. The improved outcome was observed to be independent of patients' smoking status, age, gender, or baseline disease level. There was no difference in the incidence of adverse effects among treatment groups.

CONCLUSIONS

Scaling and root planing plus minocycline microspheres is more effective than scaling and root planing alone in reducing probing depths in periodontitis patients.

Activation of protease-activated receptors by gingipains from Porphyromonas gingivalis leads to platelet aggregation: a new trait in microbial pathogenicity

The bacterium Porphyromonas gingivalis is a major etiologic agent in the pathogenesis of adult periodontitis in humans. Cysteine proteinases produced by this pathogen, termed gingipains, are considered to be important virulence factors. Among many other potentially deleterious activities, arginine-specific gingipains-R (RgpB and HRgpA) efficiently activate coagulation factors. To further expand knowledge of the interaction between gingipains and the clotting cascade, this study examined their effects on cellular components of the coagulation system. The enzymes induced an increase in intracellular calcium in human platelets at nanomolar concentrations and caused platelet aggregation with efficiency comparable to thrombin. Both effects were dependent on the proteolytic activity of the enzymes. Based on desensitization studies carried out with thrombin and peptide receptor agonists, and immunoinhibition experiments, gingipains-R appeared to be activating the protease-activated receptors, (PAR)-1 and -4, expressed on the surface of platelets. This was confirmed by the finding that HRgpA and RgpB potently activated PAR-1 and PAR-4 in transfected cells stably expressing these receptors. Cumulatively, the results indicate the existence of a novel pathway of host cell activation by bacterial proteinases through PAR cleavage. This mechanism not only represents a new trait in bacterial pathogenicity, but may also explain an emerging link between periodontitis and cardiovascular disease. (Blood. 2001;97:3790-3797)

Circulating concentrations of C-reactive protein and total sialic acid in tobacco smokers remain unchanged following one year of validated smoking cessation

BACKGROUND

Elevated plasma concentrations of C-reactive protein (CRP) and total sialic acid (TSA) have been associated with increased cardiovascular risk. Additionally, levels of both CRP and TSA have been reported to be significantly elevated in smokers. However, it is not clear if the raised TSA and CRP levels noted in smokers are directly attributable to the smoking experience, or if they may be elevated due to a secondary mechanism(s), such as smoking-induced tissue inflammation.

SUBJECTS AND METHODS

We measured the plasma concentration of CRP and TSA in a group of smokers at baseline and following one year of validated smoking cessation (n = 30) and in a control group of tobacco users who continued to smoke over the year (n = 30).

RESULTS

The baseline concentration of TSA and CRP was 67.2 mg dL(-1) and 1.91 mg L(-1), respectively (n = 60). No significant dose-dependent relationship was noted between baseline CRP or TSA concentration and either plasma cotinine, expired-air CO or daily cigarette consumption. There was no difference in the mean change in CRP level in the quitters over one year (- 0.2 mg L(-1)) compared to the continuing smokers (+ 0.5 mg L(-1)), P = 0.80, or in the change in concentration of TSA in the quitters (- 2.7 mg dL(-1)) compared to the continuing smokers (+ 0.4 mg dL(-1)), P = 0.26.

CONCLUSIONS

As the circulating concentrations of both CRP and TSA remain unchanged following one year of smoking cessation, these results would suggest that the elevated levels noted in smokers are not directly attributable to tobacco use and are more likely to be elevated due to a secondary process that is yet to be established.

Age, dental infections, and coronary heart disease

Epidemiological and intervention studies have suggested that infections are risk factors for coronary heart disease (CHD). Dental infections have appeared as cardiovascular risk factors in cross-sectional and in follow-up studies, and the association has been independent of the "classic" coronary risk factors. This case-control study aimed at detailed assessment of the dental pathology found in various CHD categories (including elderly patients). Altogether, 85 patients with proven coronary heart disease and 53 random controls, matched for sex, age, geographic area, and socio-economic status, were compared with regard to dental status, assessed blindly with four separate scores, and to the "classic" coronary risk factors (seven of the controls had CHD, and they were not included in the analyses). The dental indices were higher among CHD patients than in the controls, but, contrary to previous studies, the differences were not significant (between the CHD patients and their matched controls or among the different CHD categories). This result could not be explained by potential confounding factors. The participants in the present study were older and had more often undergone recent dental treatment in comparison with subjects in our earlier studies. Age correlated with the severity of dental infections only in the random controls but not in the coronary patients who, although young, already had high dental scores. We believe that the higher age of the participants in the present study is the most likely reason for the results. Other possible explanations include an age-related selection bias among older CHD patients, and the fact that those participating in studies like this may have better general health and thus also less severe dental infections. Thus, the role of dental infections as a coronary risk factor varies according to the characteristics of the population studied.

Anaerobic Periodontal Infections as Risk Factors for Medical Diseases

Advanced forms of periodontal disease are associated with the overgrowth of a limited number of gram-negative anaerobic species in plaques found in periodontal pockets. Double-blind clinical trials of metronidazole and doxycycline, combined with debriding of the tooth surfaces, have significantly reduced the need for periodontal surgery. Epidemiologic studies have indicated that untreated periodontal disease could be a risk factor for preterm delivery of low birth weight infants, coronary heart disease, and cerebral vascular accidents. This is because gram-negative anaerobic species implicated in periodontal disease, eg, Bacteroides forsythus, Porphyromonas gingivalis, and Treponema denticola, could introduce lipopolysaccharides, heat-shock proteins, and proinflammatory cytokines into the blood stream. If periodontal disease is a risk factor for cardiovascular disease, then it is a modifiable risk factor, as periodontal disease is treatable.

Periodontitis: a risk factor for coronary heart disease?

This paper evaluates the current information on the relationship between oral disease (specifically periodontitis) and atherosclerosis/coronary heart disease (CHD) to determine whether the information is sufficient to conclude that periodontitis is a risk factor for atherosclerosis/CHD. As background for this evaluation, the term "risk factor" is defined, and the 3 criteria used to establish exposures as risk factors are reviewed. In addition, epidemiologic criteria for defining an exposure as causal are presented. The available evidence then is evaluated according to the criteria for causality, which are extensions of the criteria for establishing a risk factor. This review is done in the context of the relationship between atherosclerosis/CHD and inflammation. A number of findings are briefly reviewed that link inflammation and atherosclerosis/CHD, such as: 1) prior flu-like symptoms were more common in cases of myocardial infarction than in concurrently sampled controls; 2) high levels of cytomegalovirus antibody titers were associated with elevated carotid intimal-medial wall thickness 18 years later; 3) prior infection with cytomegalovirus was a strong independent risk factor for restenosis after coronary atherectomy; 4) dental infections were more common in cases of cerebral infarction compared to community controls matched on age and sex; and 5) the gingival index was significantly correlated with fibrinogen and white cell counts in periodontal patients and controls, adjusted for age, smoking, and socioeconomic status. Three case-control studies and 5 longitudinal studies investigating the relationship between dental conditions and atherosclerosis/CHD are reviewed in terms of strength of associations, consistency of associations, specificity. of associations, time sequence between exposure and outcome, and degree of exposure and outcome. Related to the last criterion, new findings are presented which indicate that the extent of the periodontal infection, a measure reflecting microbial burden, also is related to onset of new CHD events. Our previously published model describing the potential biological mechanisms underlying the associations found is reviewed. This model places the associations into a context of an intrinsic or acquired hyperinflammatory monocyte trait that results in a more intense inflammatory response to lipopolysaccharide (LPS) challenges, such as periodontal infections. This hyperinflammatory response may promote atheroma formation and thromboembolic events. finally, new findings from ongoing animal studies are presented, indicating that high fat diets in atherosclerotic-susceptible mice induce greater inflammatory responses to Porphyromonas gingivalis challenges. We conclude that the available evidence does allow an interpretation of periodontitis being a risk factor for atherosclerosis/CHD. This conclusion, however. is made with some qualifications. While the associations found across a wide variety of subjects are remarkably consistent, for the most part they are represented by incidence odds ratios around 2.0. While this level of association would result in oral conditions contributing to a large number of CHD cases, it is possible that associations of this magnitude are due to bias in the study designs. In addition, some studies report that periodontitis is associated with all-cause mortality and low birth weight infants. These multiple associations detract from the credibility of periodontitis as a risk factor, as specificity of association is more often related to causality. However, all-cause mortality may largely be driven by mortality from cardiovascular events: and some exposures, such as smoking. are indeed risk factors for multiple conditions. On the other hand, current findings regarding the associations between oral conditions and atherosclerosis/CHD imply that the criteria for causality may be met in the not-too-distant future.

Assessing the relationship between dental disease and coronary heart disease in elderly U.S. veterans

Several recent studies have shown a link between dental disease and coronary heart disease. The authors studied 320 U.S. veterans in a convenience sample to assess the relationship between oral health and systemic diseases among older people. They present cross-sectional data confirming that a statistically significant association exists between a diagnosis of coronary heart disease and certain oral health parameters, such as the number of missing teeth, plaque benzoyl-DL-arginine-naphthylamide test scores, salivary levels of Streptococcus sanguis and complaints of xerostomia. The oral parameters in these subjects were independent of and more strongly associated with coronary heart disease than were recognized risk factors, such as serum cholesterol levels, body mass index, diabetes and smoking status. However, because of the convenience sample studied, these findings cannot be generalized to other populations.

Association between acute cerebrovascular ischemia and chronic and recurrent infection

BACKGROUND AND PURPOSE

We performed a case-control study to investigate whether chronic or recurrent respiratory, ear-nose-throat (ENT), and dental infections are risk factors for cerebrovascular ischemia.

METHODS

Using a standardized questionnaire we investigated past infectious diseases in 166 consecutive patients with acute cerebrovascular ischemia and in 166 age- and sex-matched nonstroke neurological patient controls. In subgroups, we performed standardized ENT (69 patients, 66 control subjects) and dental examinations including orthopantomography (66 patients, 60 control subjects). Dental status was determined by a total dental index (TDI) that reflects caries, periapical lesions, periodontitis, and other dental lesions and by an orthopantomography index (OPGI) that was assessed blinded.

RESULTS

Frequent (> or = 2 episodes in each of the 2 preceding years) or chronic bronchitis was associated with cerebrovascular ischemia in age-adjusted multiple logistic regression analysis (odds ratio, OR, 2.2; 95% confidence interval, CI, 1.04 to 4.6). Groups were not different in ENT examination. Patients tended to have a worse dental status (TDI: P = .070; OPGI: P = .062) and had more severe periodontitis (P = .047) and periapical lesions (P = .027) than control subjects. In age-adjusted multiple logistic regression analysis with social status and established vascular risk factors, poor dental status (TDI) was independently associated with cerebrovascular ischemia (OR, 2.6; 95% CI, 1.18 to 5.7).

CONCLUSION

Recurrent or chronic bronchial infection and poor dental status, mainly resulting from chronic dental infection, may be associated with an increased risk for cerebrovascular ischemia.

Periodontal disease and cardiovascular disease

It is our central hypothesis that periodontal diseases, which are chronic Gram-negative infections, represent a previously unrecognized risk factor for atherosclerosis and thromboembolic events. Previous studies have demonstrated an association between periodontal disease severity and risk of coronary heart disease and stroke. We hypothesize that this association may be due to an underlying inflammatory response trait, which places an individual at high risk for developing both periodontal disease and atherosclerosis. We further suggest that periodontal disease, once established, provides a biological burden of endotoxin (lipopolysaccharide) and inflammatory cytokines (especially TxA2, IL-1 beta, PGE2, and TNF-alpha) which serve to initiate and exacerbate atherogenesis and thromboembolic events. A cohort study was conducted using combined data from the Normative Aging Study and the Dental Longitudinal Study sponsored by the United States Department of Veterans Affairs. Mean bone loss scores and worst probing pocket depth scores per tooth were measured on 1,147 men during 1968 to 1971. Information gathered during follow-up examinations showed that 207 men developed coronary heart disease (CHD), 59 died of CHD, and 40 had strokes. Incidence odds ratios adjusted for established cardiovascular risk factors were 1.5, 1.9, and 2.8 for bone loss and total CHD, fatal CHD, and stroke, respectively. Levels of bone loss and cumulative incidence of total CHD and fatal CHD indicated a biologic gradient between severity of exposure and occurrence of disease.

Poor oral health and coronary heart disease

A few recent studies have shown associations between poor oral health and coronary heart disease (CHD). The objective of this study was to examine the incidence of CHD in relation to number of teeth present and periodontal disease, and to explore potential mediators of this association, in a prospective cohort study. This study is a part of the ongoing Health Professionals Follow-Up Study (HPFS). Participants included a US national sample of 44,119 male health professionals (58% of whom were dentists), from 40 to 75 years of age, who reported no diagnosed CHD, cancer, or diabetes at baseline. We recorded 757 incident cases of CHD, including fatal and non-fatal myocardial infarction and sudden death, in six years of follow-up. Among men who reported pre-existing periodontal disease, those with 10 or fewer teeth were at increased risk of CHD compared with men with 25 or more teeth (relative risk = 1.67; 95% confidence interval, 1.03 to 2.71), after adjustment for standard CHD risk factors. Among men without pre-existing periodontal disease, no relationship was found (relative risk = 1.11; 95% confidence interval, 0.74 to 1.68). The associations were only slightly attenuated after we controlled for dietary factors. No overall associations were found between periodontal disease and coronary heart disease. Tooth loss may be associated with increased risk of CHD, primarily among those with a positive periodontal disease history; diet was only a small mediator of this association.

Symptoms of chronic bronchitis and the risk of coronary disease

BACKGROUND

Experimental and epidemiological studies show a positive association between coronary disease and various infections in different organs, both viral and bacterial and both acute and chronic. Most attention has been paid to dental infections and infections in the respiratory tract. We have studied how chronic respiratory infection predicts coronary disease.

METHODS

We defined chronic respiratory infection by the occurrence of symptoms of chronic bronchitis. We also analysed whether any association with coronary disease incidence and mortality is independent of the known major cardiovascular risk factors and whether it is similar among persons in different occupations. Our cohort study was a 13-year follow-up of 19,444 randomly selected eastern Finnish men and women born between 1913 and 1947 and examined in either 1972 or 1977.

FINDINGS

During follow-up, there were 1419 first coronary events, either fatal or non-fatal, and 614 coronary deaths. Among men, the age-adjusted and study-year-adjusted risk ratio of long lasting-symptoms of chronic bronchitis (during as much as 3 months in a year) was 1.52 (95% CI 1.33-1.75) for coronary disease and 1.74 (CI 1.43-2.11) for coronary death. Among women the risk ratios were 1.38 (1.07-1.78) and 1.49 (0.98-2.27), respectively. Inclusion of smoking, serum cholesterol, and systolic blood pressure into the models decreased risk ratios to 1.36 (1.17-1.56) and 1.55 (1.26-1.90) in men and to 1.34 (1.04-1.74) and 1.41 (0.92-2.16) in women, respectively. The risk of coronary disease associated with the symptoms of chronic bronchitis was similar among blue-collar and white-collar workers but the association was not found among farmers.

INTERPRETATION

Symptoms of chronic bronchitis predicted the risk of coronary disease independently from the known major cardiovascular risk factors. If the observed association is causal, prevention and improved management of chronic infections may have played a role in the decrease in coronary disease mortality observed in eastern Finland in the past two decades.

Infection as a risk factor for infarction and atherosclerosis

A growing amount of clinical and experimental evidence suggests a link between infection and atherosclerotic diseases including both myocardial and cerebral infarction. A prime example is a greatly increased risk of stroke in septicaemic patients with and without endocarditis. Controlled clinical studies have recently shown, however, that certain other milder bacterial infections are also a risk factor for infarction. A preceding febrile respiratory infection was a major risk factor for stroke in young and middle aged patients. In patients with acute myocardial infarction Chlamydia pneumoniae and dental infections seem to be risk factors according to one controlled clinical study. Several possible mechanisms could explain the observed association of infection and infarction. For instance, infection causes a hypercoagulable state which increases the risk of thrombosis. In addition, infection has profound and harmful effects on prostaglandin and lipid metabolism. Infection may also have some role in the atherosclerotic process itself by inducing damage and inflammation in vascular endothelium in the presence of hypercholesterolemia. So far, however, little clinical evidence is available to suggest that by controlling infection the risk of infarction or development of atherosclerotic lesions might be reduced except in patients with endocarditis, where the risk of thromboembolic complications rapidly diminished when the infection is controlled with antimicrobial therapy.