Possible source of neurotoxic mercury waste

Dental chair a possible source of neurotoxic mercury waste

Mercury is a large component of dental fillings, but it is not believed to pose immediate health risks in that form. When exposed to sulfate-reducing bacteria, however, mercury undergoes a chemical change and becomes methylated, making it a potent, ingestible neurotoxin.

While the major source of neurotoxic mercury comes from coal-fired electric power plants, researchers at the University of Illinois at Chicago and at Urbana-Champaign say mercury entering drain water from dental clinics and offices is also a source.

"We found the highest levels of methyl mercury ever reported in any environmental water sample," said Karl Rockne, associate professor of environmental engineering at UIC and corresponding author of the study that appeared online March 12 in the journal Environmental Science and Technology.

Working with James Drummond, UIC professor of restorative dentistry, Rockne gathered waste water samples in collection tanks generated from both a single-chair dentist's office and a 12-chair dental clinic to check for methyl mercury.

Water collected was allowed to settle. Clear layers above the settled particles were then analyzed for presence of methyl mercury. Fine, slow-settling particles of mercury get into the waste water mostly after dentists use high-speed drills to remove old amalgam fillings. The numerous fine particles the drilling produces provide an ample source of exposed mercury surfaces, making them prime targets for sulfur-reducing bacteria that commonly live in anaerobic conditions and are known to methylate mercury.

"It appears to be produced partially, if not fully in the waste water, and it's being produced very rapidly," said Rockne, adding that it was significant this was happening before the particles were getting into sewers, where sulfur-reducing bacteria thrive.

The finding raised the question whether the culprit bacteria were living in the mouths of dental patients. "We don't have the answer," Rockne said.

Based on their sample studies, the researchers estimate that 2-5 kilograms, or up to 11 pounds, of methyl mercury could be entering the public water supply of the United States each year from dental waste water. While this may not seem like much, methyl mercury is highly toxic in minute amounts.

When in waterways, methyl mercury tends to get biomagnified up the food chain, moving from algae and phytoplankton to fish and, ultimately, to humans.

While surprised by the level of contaminants found in the study, Rockne says follow-up research is necessary -- then, possibly, some basic engineering.

"Amalgam separators are a good first step, but maybe something else is necessary downstream to prevent further methylation and prevent further soluble mercury from getting through the system," he said.

"We have to take more steps to prevent the problem from occurring in the first place," he said. "We're dealing with a pipe -- a control point. As an engineer, I see this as a problem that is tractable -- something we can definitely do something about."

Dental materials = infection for diabetic patients

Medications plus dental materials may equal infection for diabetic patients

CPeople who live with diabetes on a daily basis are usually instructed to eat right, maintain regular physical activity, and if necessary, take medication. What many may not know is that these medications that help control healthy insulin levels may lead to unexpected events at the dentist’s office. According to a study in the November/December 2007 issue of General Dentistry, the AGD’s clinical, peer-reviewed journal, diabetic patients especially need to communicate special needs to their dentists. This is due to harmful interactions that could occur because of the materials and medications used at dental appointments.

According to the study, more than 194 million people worldwide have diabetes, and health officials estimate that this figure will double or triple in less than 20 years. “It is imperative that diabetic patients inform their dentist of their needs in order to anticipate medication interactions and physical reactions to treatment,” says Lee Shackelford, DDS, FAGD, spokesperson for the AGD. “The doctor must know if the patient is taking insulin, and has taken their daily dose of insulin, in order to anticipate the length of the appointment.”

It does not stop, however, with diabetic patients; providing dentists with as much information as possible about current medications is essential for everyone’s oral health. “It is important that your dentist is aware of all of the medications that you are taking, including prescription drugs, over-the-counter medications, and herbal drugs as they may interact with agents that your dentist may use for your dental treatment,” advises lead author of the study, James Little, DMD, MS.

“Talk with your dentist if you are concerned about how the medications you are taking could affect your oral health,” advises Dr. Shackelford. “Open communication is the best way to ensure that your dentist gives you the best treatment possible.”

Steps diabetic patients can take to ensure optimal dental care:

Find a dentist who is aware of the needs of diabetic patients.
See the dentist on a regular basis and alert him or her of any changes in health status and medications.
Inform the dentist of any sores, swellings, or areas of redness in the mouth, as well as any painful areas in the mouth.
Eat a normal meal prior to the dental appointment, take all diabetic medications on schedule, bringing a blood sugar monitoring device to the appointment, and inform the dentist if symptoms associated with low blood sugar are felt.

Popular energy drinks also cause tooth erosion

For more than 10 years, energy drinks in the United States have been on the rise, promising consumers more “oomph” in their day. In fact, it is estimated that the energy drink market will hit $10 billion by 2010. While that may be great news for energy drink companies, it could mean a different story for the oral health of consumers who sometimes daily rely on these drinks for that extra boost.

Previous scientific research findings have helped to warn consumers that the pH (potential of hydrogen) levels in beverages such as soda could lead to tooth erosion, the breakdown of tooth structure caused by the effect of acid on the teeth that leads to decay. The studies revealed that, whether diet or regular, ice tea or root beer, the acidity level in popular beverages that consumers drink every day contributes to the erosion of enamel.

However, in a recent study that appears in the November/December 2007 issue of General Dentistry, the Academy of General Dentistry’s (AGD) clinical, peer reviewed journal, the pH level of soft drinks isn’t the only factor that causes dental erosion. A beverage’s “buffering capacity,” or the ability to neutralize acid, plays a significant role in the cause of dental erosion.

The study examined the acidity levels of five popular beverages on the market. The results proved that popular “high energy” and sports drinks had the highest mean buffering capacity, resulting in the strongest potential for erosion of enamel.

According to the study, the popularity of energy drinks is on the rise, especially among adolescents and young adults. Their permanent teeth are more susceptible to attack from the acids found in soft drinks, due to the porous quality of their immature tooth enamel. As a result, there is high potential for erosion among this age demographic to increase.

In fact, Raymond Martin, DDS, MAGD, AGD spokesperson, says he treats more patients in their teens to 20s for tooth erosion. “They drink a great deal more sodas, sports drinks, and energy drinks,” he says. “The results, if not treated early and if extensive, can lead to very severe dental issues that would require full mouth rehabilitation to correct,” says Dr. Martin.

Drink responsibly for your oral health:

Use a straw positioned at the back of the mouth so that the liquid avoids the teeth
Rinse the mouth with water after drinking acidic beverages
Limit the intake of sodas, sports drinks and energy drinks