Two recent articles explore the possible relationships between oral bacteria - particularly those that cause periodontitis - and cardiovascular disease.
Sara C. Gordon, BSc, BA, DDS, MSc, FRCD(C), and colleagues reviewed the literature and published their findings recently in the Journal of the Canadian Dental Association. (Gordon S, Barasch A, Foong WC, ElGeneidy AK, Safford MM. Does dental disease hurt your heart? J Can Dent Assoc 2005; 71(2):93-95. Available at www.cda-adc.ca/jcda/vol-71/issue-2/93.html) By doing this review and critically evaluating available evidence, the authors hoped to answer such questions as, “What can a clinician say to patients who may be contemplating radical measures to eliminate dental disease as a means of controlling their risk of heart disease?” or “Can dentists advertise control of oral disease as ‘good for your heart’?”
At the end of the day, the authors concluded that “the debate about whether periodontal disease is a risk factor for CVD is interesting, but still unresolved.” Although they did find some evidence of greater relative risk for CVD in patients with periodontitis, the potential effects of confounding factors, such as smoking and diabetes, could not be determined. The authors reported that although the relationship between oral bacteria and CVD is plausible, it cannot be definitively established until disease mechanisms related to CVD are better understood.
However, Gordon et al. emphasized a very important point: “Patients should be encouraged to concentrate on controlling well-known risk factors for CVD and to seek the well-documented benefits of treating dental disease…”
In the second study, published recently in Circulation, researchers reported the first evidence of a direct association between CVD and bacteria that cause periodontal disease, but still say the findings do not prove that oral bacteria cause CVD, either directly or indirectly. (Desvarieux M, Demmer RT, Rundek T, Boden-Albala B, Jacobs DR Jr, Sacco RL, Papapanou PN. Periodontal microbiota and carotid intima-media thickness. The Oral Infections and Vascular Disease Epidemiology Study [INVEST]. Circulation 2005; 111:576-582)
The INVEST study was supported by four agencies of the National Institutes of Health. Controlling for several risk factors - such as smoking and diabetes - that might skew the data, the INVEST researchers found that older adults whose mouths have high proportions of four periodontal-disease-causing bacteria also tend to have thicker carotid arteries, which strongly predicts stroke and heart attack. These findings could be significant because about 200 million Americans are affected by periodontal disease in varying degrees.
“What was interesting to us was the specificity of the association,” said Moïse Desvarieux, MD, PhD, the study’s lead author and an infectious disease epidemiologist at Columbia University’s Mailman School of Public Health and the University of Minnesota. “These same four bacteria were there, they were always there in the analysis, and the relationship seems to be pretty much, with one exception, limited to them.”
Desvarieux explained that even though these findings shed new light on a long-controversial health issue, they cannot answer the more specific public health questions about cardiovascular disease. Because the 657 people in the study had their oral bacteria and carotid thickness measured at the same point in time, “it’s impossible to know which comes first, the periodontal disease or thickening of the carotid artery,” Desvarieux said. Answering that question is the only way to definitively establish whether or not chronic inflammation or infection caused the thickening of the carotid arteries.
Another author of this paper, Ralph Sacco, MD, MS, associate chair of neurology, professor of neurology and epidemiology, and the director of the Stroke and Critical Care Division of Columbia University College of Physicians and Surgeons, said that study participants will be re-examined in about three years “and, at that point, we can better evaluate the progression of the atherosclerosis and, hopefully, begin to establish a time frame underlying the diseases.”
United Kingdom Women Dentists’ Survey
England’s Department of Health published findings from a survey on the need to improve employment opportunities for women dentists in the country’s National Health Service (NHS). Although most of the findings were NHS-specific, some are likely relevant for women dentists everywhere:
• 43 percent of the women currently practicing [in the NHS] are the main income provider in the household and feature most prominently among younger age groups.
• 52 percent of women dentists found that an obstacle to returning to work [e.g., after having a baby] was the emotional difficulty associated with leaving children. Arranging childcare and loss of confidence were also major issues.
• 92 percent of respondents who tried to obtain part-time work were successful. The main reason for wishing to work part-time was caring for children (65 percent).
• The burden of the administrative and management side of running a business was consistently referred to as a disincentive during the review.
Researchers in the UK obtained their data from written submissions from organizations, from focus groups held across England, and from 4,500 completed questionnaires. The final report, available online at www.doh.gov.uk/dental/betteropportunitiesforwomendentists, covers aspects of dental practice, working patterns, returning to dentistry, practice ownership, and career satisfaction and advice. Other material presented in the report includes relevant issues raised by participants in the survey, a general discussion of findings, and a complete list of specific recommendations.
Japanese Researchers Produce Artificial Tooth Enamel
A brief report in the journal Nature describes a new dental therapy, currently undergoing clinical trials in Japan, that regenerates tooth enamel and eliminates the need for handpieces. (Yamagishi K, Onuma K, Suzuki T, Okada F, Tagami J, Otsuki M, Senawangse P. A synthetic enamel for rapid tooth repair. Nature 2005; 433:819)
The authors report that conventional treatment of dental caries is “not ideal for tiny early lesions because a disproportionate amount of healthy tooth must be removed to make the alloy or resin stick.” Dr. Kazue Yamagishi and her research team at the FAP Dental Institute in Tokyo have developed an alternative treatment - a synthetic enamel that repairs the tooth and protects it from further decay at the same time. On her Web site (http://homepage2.nifty.com/nmc/home.html), Dr. Yamagishi states her belief that this protective effect eventually “will provide a tremendous decrease in the total incidence of tooth decay.”
This product is expected to be available within two to three years, after clinical trials confirm its safety. It will be used under the supervision of dentists, because the paste is highly acidic, therefore making it unsuitable for at-home applications in toothpaste. However, it presents the distinct possibility that preventive dental treatments may be just over the horizon.
Root Caries Prevention Advances
An article in a special supplement to the journal Caries Research reviews the effects of dentifrices with high fluoride contents on the management of root caries. (Lynch E, Baysan A. Reversal of primary root caries using a dentifrice with a high fluoride content. Caries Res 2001; 35[Suppl 1]:60-64) Primary root caries lesions (PRCLs), which are a widespread and often serious problem in older populations, can be difficult to restore. According to this paper, “It is generally accepted that fluoride ions promote remineralization of tooth substances and reduce the rate of demineralization. The use of a dentifrice with a high fluoride content may be considered to reverse PRCLs, since more fluoride is required for the remineralization of roots than for enamel.”