Chinese Dental Labs Turn Lead into Gold…?
When a 73-year-old Ohio woman fell ill, the news made national headlines. It wasn’t old age, or pneumonia, or cancer, or anything else you might expect. She had gotten lead poisoning from her new dental bridge.
Though she’d visited an American dentist, the bridge itself had been fabricated by a Chinese lab. Let me assure you that this is major news. I expect this health scandal will rock the world of dentistry.
|Lead: How Many Parts Per Million Is Okay?|
|210||Discovered in one Chinese-made crown|
|160||Discovered in Ohio woman’s dental bridge|
|600||US legal limit in paint, toys, etc.|
|90||International standard for items such as toys (now being considered by US Congress)|
|1||Amount the UK permits in dental work|
|0.5-3||FDA guidelines for leachable lead in ceramic dishware|
|0.1||FDA limit in candy and food|
|0.1||Amount naturally in a healthy person’s blood|
The Ohio woman received this new dental bridge last year. However, the restoration site became inflamed, and chewing was unmanageably painful. The bridge was ultimately removed, and she’s had further surgeries since. She sent the bridge in question to a scientific testing laboratory, and its surface allegedly tested at 160 parts per million of lead. She has since retained a lawyer and is planning to sue her dentist. (Please note that she is planning to sue her dentist, not the dental lab!)
Chinese exports have received massive amounts of bad press after various health scandals. Do you remember the animals who died from eating tainted pet food? Then at least 21 Panamanians died after taking poison cough syrup. Danger made its way onto US shelves via toxic toothpaste. Most recently, children’s toys were pulled from the market after it was discovered that the paint contained high amounts of lead. All of these products were manufactured in China.
I know what many of you dentists are wondering: Is this for real? What evidence is there that Chinese labs are systematically producing lead-tainted dental restorations? Well, here’s the evidence that has so far come to light on this developing story:
- The Ohio woman’s partial bridge apparently tested at 160 parts per million of lead.
- Ohio TV station WBNS then conducted its own investigation, releasing the results on February 27. With the help of a local dentist, they ordered crowns from four different Chinese dental labs. One of the eight crowns tested positive for lead. The porcelain facing contained 210 parts per million.
- The ADA announced that it had begun its own investigation, and had recommended that the FDA and CDC do the same. (Read the ADA’s response and their talking points for dentists.)
Though most press focuses on work manufactured in China, it’s worth noting that products are imported from many other countries, including India and Mexico. Imported restorations are dramatically less expensive than work produced domestically; in some cases, a crown from China may cost as much as 90% less. Cost-saving measures have led to more and more international manufacturing.
In the US, about 15-20% of dental lab work is produced in China (primarily bridges and crowns); that’s 7 million foreign crowns each year. Many of these products are distributed by American labs. Three years ago, less that 1% of UK dental restorations were produced in China; that number is now up to 5%.
Theoretically, the FDA monitors all dental products, whether produced domestically or abroad. The FDA has the authority to inspect any dental lab, foreign or domestic, that makes products sold in the US. Dental labs with overseas operations must register with the FDA. But within the US, only three states (Texas, Kentucky and South Carolina) require dental labs to register with state health departments.
The National Association of Dental Labs (NADL) officially recommended that the FDA close some of these legal loopholes. Needless to say, the organization that represents 1400 US dental labs has grave concerns about the allegations of tainted dental products.
The lead appears to be in the porcelain surface of some restorations. But many foreign labs use porcelain and other materials made in the US or Europe. So where does the lead come from? Many suspect the lead is in the glaze used to stain and seal the porcelain.
Many pottery glazes contain lead. The lead itself is not particularly a problem until it comes into contact with acid. The acid is what allows the lead to leach out of the glaze. For pottery, this isn’t much of a problem. But since the human mouth is an acidic environment, lead might be transferred to the patient’s bloodstream.
Let’s be clear on this point: The FDA says there should not be detectable levels of lead in the surface material of a dental prosthetic device. Lead poisoning generally causes non-specific symptoms such as aches, abnormal bowels, or high blood pressure. As a result, proper diagnosis can take years.
Though labs are supposed to label outsourced work they provide to dentists, anecdotal evidence suggests that dentists do not in fact always know where their restorations were manufactured. Dentists: Do you know where your restorations are manufactured? Estimates suggest that 25% of US dentists are sending lab work to China – and what’s more, many of these dentists don’t even know it. You can’t just assume your dental lab does its own manufacturing. As a dentist, it’s your job to make sure you can stand behind the safety of any restorations you do.
Anyhow, folks, that’s just the tip of the iceberg! Check your inbox this Friday for a survey question on foreign dental labs. And you definitely won’t want to miss my next editorial. Do you know which of the major US dental labs import or manufacture foreign dental work? I do! And next week, I’ll start naming names.