Forget amalgam and fluoride. Could lead be dentistry's new bogeyman? The ADA said today that it is investigating reports of potentially dangerous levels of the element in imported crowns.
The concern stems from an investigation by WBNS-TV of Columbus, Ohio, which sent eight dental crowns from China to a certified testing facility. The facility found 210 parts of lead per million in one of them.
Is that enough lead to sicken a patient? The answer is unclear. The lead found in this crown falls within the current limit set by the Consumer Product Safety Commission of 600 parts per million for consumer products. But crowns are unlike most products regulated by the commission because they are used inside the consumer's mouth raising questions about whether they should meet a different standard. Congress is currently considering a limit of only 90 parts per million for toys.
The root of the problem, according to Bennett Napier, co-executive director of the National Association of Dental Laboratories, is that dental labs are under-regulated. Standards are too low for U.S. domestic labs, but the problem is even more severe for foreign ones.
"The FDA is inspecting less than 1 percent of the dental work coming in from overseas," Bennet told DrBicuspid.com. "We are not aware of any reported cases of domestic products contaminated with lead. However, there are four documented cases of contaminated foreign products."
For its part, the American Dental Association is taking the report "seriously," but keeping it "perspective."
"There simply isn’t enough information available to presume that the presence of lead in dental crowns or other prostheses is widespread," says the ADA Web site. "An estimated 15 to 20 percent of prostheses used in the U.S. originate in foreign labs, and an even smaller percentage originate in China."
Still, the ADA has alerted its members about the report, and announced its own investigation into the matter.
It has issued a list of questions that patients are likely to ask about dental restorations:
- Do you fashion your own crowns, bridges, etc., or purchase them from a dental laboratory?
- Where is the dental lab located?
- Does the lab outsource crowns or bridges to a foreign country?
- If the lab is in a foreign country, does it provide written documentation that it is registered with the FDA?
- Does the lab provide written documentation that it uses FDA-approved materials?
- Have you noticed any problems with the crowns, bridges or other items produced by this dental lab?
It had also issued a tip sheet for dentists concerned about lead contamination.
