Month: January 2010
Mercury Fillings May Be Less Toxic: Caution Still Needed
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
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