Health

Aging Causes Fracture Toughness Reduction in Dentin

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Researchers led by Dr. Dwayne D. Arola of the University of Maryland, have recently examined the role of aging and its affect on the reduction in fracture toughness of human dentin. The article appears on the Journal of the Mechanical Behavior of Biomedical Materials (October 2009 issue, pages 550-559). Dr. Arola and colleagues found that the average fracture toughness of  old dentin was approximately 30% lower than young dentin. The researchers observed that the fracture toughness seemed to depend on the number of lumens, which is important in determining the mineral-to-collagen ratio and the variation in the degree of age-related sclerosis, or embrittlement, throughout dentin. They were able to do this by examining the crack growth resistance of human coronal dentin using tissue obtained from patients 18 to 83 years of age and for crack extension oriented perpendicular to the … Read more

White Paper on Ethics & Professionalism in Dental Education

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The American Student Dental Association (ASDA) has recently published a White Paper on Ethics & Professionalism in Dental Education which can be found at http://www.asdanet.org/uploadedFiles/The_Issues/ASDA%20White%20Paper%20Final-Newcomb.pdf The paper is designed to help address issues of cheating which have occurred at dental schools. The ASDA Student Code of Ethics states that, “ASDA recognizes the importance of high ethical standards in the dental school setting. Therefore, the Association believes students should conduct themselves in a manner reflecting integrity and fairness in both the didactic and clinical learning environments. Ethical and professional behavior by dental students is characterized by honesty, fairness, and integrity in all circumstances; respect for the rights, differences, and property of others; concern for the welfare of patients, competence in the delivery of care, and preservation of confidentiality in all situations where this is warranted.” The paper addresses some of the … Read more

ADA EBD Champions Conference 2010

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The American Dental Association (ADA) is looking for dentists interested in spreading the word about evidence-based dentistry to attend the EBD Champions Conference March 26-27, 2010, at ADA Headquarters in Chicago, IL. The deadline for applications is faster approaching and is Jan. 30, 2010. The conference is sponsored by the ADA and the Journal of Evidence-Based Dental Practice and supported by an educational grant from Procter & Gamble. The event is a unique opportunity for dentists to become resources to their local dental communities by promoting an evidence-based approach to patient treatment and disease prevention. I am glad to see that dentists are gathering to discuss evidence-based dentistry and feel that if you are able to make the conference, it would be well worth it. For more information about the conference or to apply to become an EBD Champion, visit … Read more

Mercury Fillings May Be Less Toxic: Caution Still Needed

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A new study on the surface chemistry of silver-colored, mercury-based dental fillings suggests that the surface forms of mercury may be less toxic than that which was previously thought. Graham George and his colleagues note that mercury-based fillings (amalgams) have been used by dentists to repair teeth for over 100 years. In recent years, their use has become controversial because of concerns about exposure to potentially toxic mercury. Even so, mercury can potentially exist in several different chemical forms, each with a different toxicity. Scientists analyzed the surface of freshly prepared metal fillings and compared these with the surface of aged fillings (about 20 years old) from a dental clinic. Fresh fillings contained metallic mercury, which can be toxic. Aged fillings, on the other hand, usually contain a form of mercury, called beta-mercuric sulfide or metacinnabar. This form is unlikely … Read more

Common Bacteria Linked to MS

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Research suggests that a common oral bacteria may increase autoimmune disease. Multiple sclerosis (MS) is a disease where the immune system attacks the brain and spinal cord. It currently affects nearly around 1 in 700 people in the United States. Patients with MS have a variety of neurological symptoms, including difficulty in moving, difficulty in speech, and muscle weakness. Porphyromas gingivalis, a common oral bacterium in humans, produces a unique type of lipid, phosphorylated dihydroceramides (DHCs), which enhance inflammatory responses. These lipids are also likely produced by bacteria found in other parts of the body including the gastrointestinal tract. Researchers led byFrank C. Nichols and Robert B. Clark of the University of Connecticut Health Center administered phosphorylated DHCs in a mouse model of MS to determine if these lipids cause immune-mediated damage in autoimmune disease. The severity of disease was … Read more