Lead Found in Some Dental WorkSep 23, 2008 | Parker Waichman LLP Some dental offices outsource their dental work to other countries, and some of the crowns and bridges being manufactured in other countries have tested positive for lead. A recent CBS investigation, in which 13 crowns were purchased from labs in China, Thailand, and the United States, revealed that the overwhelming majority—10—tested positive for lead at levels ranging from 110 to 240 parts per million.
Meanwhile, the American Dental Association is conducting a study to determine if lead from foreign dental work "leeches" out. And, although, most people know that lead exposure can harm children, most don’t realize that lead can also poison adults. Still, the U.S. Food & Drug Administration has not yet established a lead limit in dental work.
DW Dental Lab owner David Wessel said he believes the lead in the crowns tested came originated from the surface stain used to whiten the teeth. "That's probably worse," he said. "It's on the surface. It's against your tongue and cheeks, and your mouth absorbs … everything into your bloodstream." Lead dissolves quickly in acid solutions such as in the stomach, allowing significant amounts of lead to be absorbed into the body. Wessel expressed reservations about the outsourcing trend. "The problem is you don't know what you're getting," he said. "You don't know what they're putting in your mouth. No matter what they tell you there's no way to prove it unless you can break it down and analyze it and tell you what it's made of." There is virtually no regulation on labs, whether they are in the U.S. or in another country.
Many consider lead poisoning to be one of the most important chronic environmental illnesses affecting children today. Exposure to lead in children and unborn children can cause brain and nervous system damage, behavioral and learning problems, slowed growth, hearing problems, headaches, mental and physical retardation, and behavioral and other health problems. Lead is also known to cause cancer and reproductive harm and, in adults, lead can damage the nervous system. Of particular concern is the developing brain because negative influences can have long-lasting effects and can continue well into puberty and beyond. Once poisoned, no organ system is immune.
A major challenge with lead poisoning is the difficulty in recognizing its subtle symptoms and that no pathognomonic—or definitive—indicators exist or point to contamination. When faced with peculiar symptoms that do not match any one particular disease, lead poisoning should be considered. Children with lead poisoning may experience irritability, sleeplessness or excess lethargy, poor appetite, headaches, abdominal pain with or without vomiting—and generally without diarrhea—constipation, and changes in activity level. A child with lead toxicity can be iron deficient and pale because of anemia and can be either hyperactive or lethargic. There may also be dental pointers, for instance, lead lines on gingival tissue. Lead poisoning in adults may present with motor problems and an increase in depressive disorders, aggressive behavior, and other maladaptive affective disorders, as well as problems with sexual performance, impotence and infertility, as well as increased fecal wastage and sleep disorders; adults may over sleep or experience difficulty falling asleep.