Periodontal pathogen load and increased antibody response to heat shock protein 60 in patients with cardiovascular disease

AIM

To determine the relationship between periodontal pathogen load and anti-human heat shock protein 60 (hHSP60) antibodies in patients with established cardiovascular disease (CVD).

MATERIALS AND METHODS

Participants were cardiovascular patients (n = 74) with a previous hospital admission for myocardial infarction. Concurrent periodontal pathogen load of Porphyromonas gingivalis, Fusobacterium nucleatum, Tannerella forsythia and Aggregatibacter actinomycetemcomitans was determined using quantitative real-time PCR. Serum antibodies to these pathogens, GroEL and hHSP60 were determined using an ELISA.

RESULTS

There was a trend for increasing anti-hHSP60 antibody as the number of bacterial species increased. The strongest positive correlations were found between anti-hHSP60 levels and numbers of T. forsythia (r = 0.43; p < 0.001) and between anti-hHSP60 and anti-GroEL levels (r = 0.39; p = 0.001). Patients with extensive periodontal pocketing (≥4 mm) had higher numbers of P. gingivalis and T. forsythia (p < 0.05) and a higher subgingival pathogen load (p < 0.05) than patients with minimal pocketing (≤1 site ≥ 4 mm). They also had significantly elevated anti-hHSP60 levels (p < 0.05). Overall, the highest anti-hHSP60 levels were seen in patients with extensive periodontal pocketing and all four bacterial species.

CONCLUSIONS

In cardiovascular patients, a greater burden of subgingival infection with increased levels of P. gingivalis and T. forsythia is associated with modestly higher anti-hHSP60 levels.

An exploratory study of the acceptability of delivering oral health information in community pharmacies

OBJECTIVE

The community pharmacy is an accessible service which, with further training and support, could be used to deliver oral health messages. This is important especially for those with systemic diseases such as diabetes mellitus and cardiovascular disease, where the oral environment may have a negative impact. This qualitative study assessed the feasibility of pharmacists delivering oral health messages in community pharmacies.

DESIGN AND METHODS

Semi-structured interviews were conducted with 49 pharmacists in Dunedin and Auckland, New Zealand, with a focus on the pharmacists' current knowledge, attitudes and possibilities for providing oral health information to patients with diabetes and cardiovascular disease.

FINDINGS

There is potential for community pharmacists to provide oral health information to patients, dependent on the approach of the pharmacist and the patient response. The majority of pharmacists agreed that providing oral health advice was within their role; however, few did so proactively. They highlighted a lack of available resources relating to oral health and systemic disease. Further training relating to oral health and systemic disease would be necessary to provide the knowledge to support any resources. The preferred option by pharmacists for such training was an evening course or workshop.

Long term use of triclosan toothpaste and thyroid function

The long term effects of usage of triclosan-containing toothpaste on thyroid function are currently unknown. Triclosan is structurally similar to thyroid hormones and reductions in serum thyroid hormone levels have been observed in animal studies following oral administration of triclosan. Therefore, an assessment of thyroid function over 4 years was undertaken in a subset of individuals in a randomised, placebo controlled clinical trial comparing the effects of 0.3% triclosan toothpaste with placebo toothpaste in subjects with coronary heart disease. Thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), antithyroglobulin antibody (anti-TGab) and antithyroid peroxidase antibody (TPOab) were measured. Paired serum samples at year 1 and year 5 from 132 subjects (64 triclosan group, 68 placebo group) were analysed. At year 1 there were no significant differences in thyroid function between the groups: mean (SD) TSH 1.4 (0.8) and 1.6 (0.9) mU/L, triclosan and placebo groups respectively, fT4 15.8 (2.2) and 15.2 (2.1) pmol/L; fT3 4.8 (0.5) and 4.8 (0.5) pmol/L. Similarly, for antithyroid antibodies there were no group differences at year 1. Median (25th, 75th percentile) for anti-TGab, 38 (34, 42) and 37 (30, 42) U/mL triclosan and placebo groups respectively; anti-TPOab, 15 (10, 22) and 18 (10, 24) U/mL. At year 5, fT4 was the only measure to show a significant difference between groups (mean and 95% Confidence Interval) 15.6 (15.1, 16.1) and 14.7 (14.2, 15.1) pmol/L triclosan and placebo respectively (p=0.01). This reflects reduced levels in the placebo group but no change in the triclosan group. In conclusion, over 4 years triclosan toothpaste had no detectable effect on thyroid function. The data support the view that 0.3% triclosan in toothpaste is safe and free of significant thyroid adverse effects.

Why should a doctor be interested in oral disease?

Oral health has been implicated in systemic disease throughout the ages; however, the understanding of the relationship between oral disease and systemic diseases such as cardiovascular disease and Type 2 diabetes mellitus is still emerging today. Chronic periodontal disease is widespread in the general population and a significant proportion of adults suffer from the most severe form of the disease. Dental plaque biofilm is necessary for the development of chronic periodontal disease with genetic and environmental factors contributing towards the pathogenesis. The putative biological mechanisms of the association between oral disease and atherogenesis are discussed, although there is insufficient evidence to establish causality at this time. Regardless of a direct causal relationship between oral disease and cardiovascular disease, treatment of oral disease leads to both a reduction in the systemic inflammatory burden as reflected in inflammatory markers and an improvement in endothelial function and hence improved overall health outcomes. A brief overview of periodontal disease including etiology, pathogenesis, screening and therapeutic implications is presented.

Diabetes, periodontitis, and the subgingival microbiota

Both type 1 and type 2 diabetes have been associated with increased severity of periodontal disease for many years. More recently, the impact of periodontal disease on glycaemic control has been investigated. The role of the oral microbiota in this two-way relationship is at this stage unknown. Further studies, of a longitudinal nature and investigating a wider array of bacterial species, are required in order to conclusively determine if there is a difference in the oral microbiota of diabetics and non-diabetics and whether this difference accounts, on the one hand, for the increased severity of periodontal disease and on the other for the poorer glycaemic control seen in diabetics.

Periodontal disease and systemic health: current status

The relationship between poor oral health and systemic diseases has been increasingly recognized over the past two decades. Indeed, the clichés "You cannot have good general health without good oral health", "The mouth is part of the body" and "Floss or die", are gaining an increasing momentum. A large number of epidemiological studies have now linked poor oral health with cardiovascular diseases, poor glycaemic control in diabetics, low birthweight preterm babies and a variety of other conditions. The majority have shown an association, although not always strong. As a result, a number of meta-analyses have been conducted and have confirmed the associations and at the same time cautioned that further studies are required, particularly with regard to the effect of periodontal treatment in reducing risk. A number of biologically plausible mechanisms have been put forward to explain the association and there is accumulating evidence in support of them, although at this stage, insufficient to establish causality. Nevertheless, the relationship between poor oral health and systemic diseases has become a significant issue, such that adult oral health can no longer be ignored in overall health strategies. This review provides an update on current understanding of the contribution of poor oral health to systemic diseases, the possible mechanisms involved and the relevance of this for general dental practitioners.

Immediate placement or immediate restoration/loading of single implants for molar tooth replacement: a systematic review and meta-analysis

PURPOSE

This systematic review and meta-analysis assessed the survival of immediately placed single implants in fresh molar extraction sites and immediately restored/loaded single molar implants in healed molar sites.

MATERIALS AND METHODS

A search of the main electronic databases, including the Cochrane Oral Health Group's Trials Register, was conducted up to November 1, 2008. The meta-analysis was prepared in accordance with the guidelines of the Academy of Osseointegration Workshop on the State of the Science on Implant Dentistry. The data were analyzed with statistical software.

RESULTS

For immediately placed molar implants, nine studies describing 1,013 implants were included to support a survival rate of 99.0%. There were no significant differences between immediate and delayed loading/restoration in molar sites (relative risk of 0.30, 95% confidence interval 0.05 to 1.61; P = .16). For immediate restoration/loading of single implants in healed molar sites, seven studies with 188 single implants were identified. In this case, the implant survival rate was 97.9%, with no difference between immediate and delayed loading (relative risk of 3.0, 95% confidence interval: 0.33 to 27.16; P = .33). Favorable marginal bone level changes in the immediate loading group were detected at 12 months (mean difference of -0.31, 95% confidence interval: -0.53 to -0.096; P = .005).

CONCLUSIONS

The protocols of immediate placement and immediate restoration/loading of single implants in mandibular molar regions showed encouraging results.

Dental stem cells and their potential role in apexogenesis and apexification

Injury to an immature permanent tooth may result in cessation of dentine deposition and root maturation leaving an open root apex and thin dentinal walls that are prone to fracture. Endodontic treatment is often complicated and protracted with an uncertain prognosis frequently resulting in premature tooth loss. Postnatal stem cells, which are capable of self-renewal, proliferation and differentiation into multiple specialized cell lineages have been isolated and identified within the dental pulp, apical papilla and periodontal ligament. The ability of these cells to produce pulp-dentine and cementum-periodontal ligament complexes in vivo suggest potential applications involving stem cells, growth factors and scaffolds for apexification or apexogenesis. Similar protein expression amongst dental stem cells possibly implicates a common origin; however, the dominant cells to repopulate an open apex will be directed by local environmental cues. A greater understanding of the structure and function of cells within their environment is necessary to regulate and facilitate cellular differentiation along a certain developmental path with subsequent tissue regeneration. This review focuses on development of the apical tissues, dental stem cells and their possible involvement clinically in closing the open root apex. MEDLINE and EMBASE computer databases were searched up to January 2009. Abstracts of all potentially relevant articles were scanned and their contents identified before retrieval of full articles. A manual search of article reference lists as well as a forward search on selected authors of these articles was undertaken. It appears that dental stem cells have the potential for continued cell division and regeneration to replace dental tissues lost through trauma or disease. Clinical applications using these cells for apexogenesis and apexification will be dependent on a greater understanding of the environment at the immature root end and what stimulates dental stem cells to begin dividing and then express a certain phenotype.

Relationship between periodontal infections and systemic disease

Oral conditions such as gingivitis and chronic periodontitis are found worldwide and are among the most prevalent microbial diseases of mankind. The cause of these common inflammatory conditions is the complex microbiota found as dental plaque, a complex microbial biofilm. Despite 3000 years of history demonstrating the influence of oral status on general health, it is only in recent decades that the association between periodontal diseases and systemic conditions such as coronary heart disease and stroke, and a higher risk of preterm low birth-weight babies, has been realised. Similarly, recognition of the threats posed by periodontal diseases to individuals with chronic diseases such as diabetes, respiratory diseases and osteoporosis is relatively recent. Despite these epidemiological associations, the mechanisms for the various relationships remain unknown. Nevertheless, a number of hypotheses have been postulated, including common susceptibility, systemic inflammation with increased circulating cytokines and mediators, direct infection and cross-reactivity or molecular mimicry between bacterial antigens and self-antigens. With respect to the latter, cross-reactive antibodies and T-cells between self heat-shock proteins (HSPs) and Porphyromonas gingivalis GroEL have been demonstrated in the peripheral blood of patients with atherosclerosis as well as in the atherosclerotic plaques themselves. In addition, P. gingivalis infection has been shown to enhance the development and progression of atherosclerosis in apoE-deficient mice. From these data, it is clear that oral infection may represent a significant risk-factor for systemic diseases, and hence the control of oral disease is essential in the prevention and management of these systemic conditions.

Radiographic study of ethnic variation in alveolar bone height among New Zealand dental students

BACKGROUND

The aim of this study was to determine anatomical variations in the radiographic distance between the cemento-enamel junction and the alveolar crest with respect to ethnic heritage and gender in New Zealand dental students.

METHODS

Digitized bitewing films of 123 second-year New Zealand dental students were examined with a computer imaging program on a desktop computer screen. The race of parents and grandparents was obtained by questionnaire.

RESULTS

The mean distance from the cemento-enamel junction to the alveolar crest across the sample was 0.97 mm. Eighteen (14.6%) of the participants had measurements >2 mm, of whom 17 were Asians. Asians had a significantly larger mean distance than did non-Asians (1.10 mm compared to 0.83 mm; P <0.001). Gender was not a significant variable.

CONCLUSIONS

Students of Asian origin had a significantly greater distance between the cemento-enamel junction and the alveolar crest. It remains to be determined whether this is anatomical or disease related.