| When an Ohio TV station recently reported that a woman’s partial bridge and dental crown, manufactured in China and exported to the U.S., tested positive for lead, reaction of the American Dental Assoc. (ADA) was immediate.
“There is no appropriate use for lead in the manufacturing of dental prostheses,” said ADA President Mark Feldman. “Our task now is to learn what the ADA can do to help prevent our members and our patients from ever hearing this kind of news again.”
Product danger and contamination stories about imports are hot topics in the media these days. The real concern for dentists and patients related to this news isn’t where dental lab work is done, but rather how dentists and their patients can be assured of the quality and safety of materials.
“When we learned of these findings, we immediately pooled our resources to determine what we should do first to guide our members and our patients,” said Dr. James Bramson, ADA executive director. “The first thing our members should do is start talking to their dental laboratories to be sure they know what methods and materials those labs are using.”
Knowledge Is Power
The first resource the ADA is providing to members is a tip sheet listing what dentists should know now and be able to learn from their dental laboratories to gain reassurance that the products made there are lead-free. ADA.org is also providing talking points to help members answer patients’ potential questions about dental work.
While the TV investigation sounded alarms, it failed to put its discoveries into any meaningful context. Specifically, how did the lead in the dental prostheses occur? Furthermore, what does it mean? What should the existence of lead in the proportions provided in the report — 160 parts per million for a bridge, 210 ppm for a crown — mean to dentists and their patients?
The ADA is devoting its resources to find out by working closely with the U.S. Food and Drug Administration and other state and federal regulatory agencies. The objective: to learn what can be done to help protect the public from potential hazards stemming from raw materials or manufacturing of dental prostheses.
The TV program didn’t have enough information to report where in the dental prostheses the lead was found. Materials experts say the stain is a likely culprit because lead helps with shading certain colors. The ADA Standards Committee on Dental Products intends to address specific requirements that test for the concentration or composition of the pigments used by dental laboratories to pigment and glaze porcelain materials.
The ADA Department of Standards works with the American National Standards Institute and the International Standards Organization to create international standards for the profession. Theoretically, it’s possible that lead could have come through a soldering process or as a contaminant from the lab environment. Standards are already in place that dental laboratories should comply with to address the safety and quality of the metal ceramic dental restorative system, including requirements to test for the metal alloy composition and concentrations of the materials.
According to stain suppliers and manufacturers contacted both here and abroad, the surface material for a dental prosthetic device should never contain lead. That’s what the FDA requires.
The ADA strongly supports state legislation in the dental practice act that requires all dental laboratories to disclose to dentists where a product was manufactured (all or part of it) and what materials were used, through documentation to the dentist. Dentists can then place documentation received from the lab about sources and materials in the patient’s chart, so that patients can request the information and it can be tracked and traced later on, if needed. The best thing for a dentist to do is to ask the lab what stains it is using and to ask the lab to provide the material safety data sheets on those stains, according to materials managers. The dental laboratory gets the material safety data sheets (MSDS) from the raw materials vendor and should provide it to the dentist.
“We develop the MSDS as part of the product development process long before we’re ready to market a product,” said Julie Noriega, manager of quality assurance and regulatory affairs for DENTSPLY Ceramco Manufacturing in Puerto Rico.
All dental laboratories, foreign and domestic, are required to comply with the FDA Quality System/Good Manufacturing Practices for products distributed in the U.S. Dental laboratories that operate overseas, serve as the initial importer for a foreign laboratory, conduct repackaging services, or manufacture sleep apnea/ snoring and other certain orthodontic appliances are required to register.
Watchful Eye
The FDA has the authority to inspect any dental laboratory manufacturing for the U.S. — registered or unregistered — here or abroad. Registration triggers periodic inspections.
Dental prostheses are among products marketed in the U.S. that require FDA clearance before they can be sold. Such products require the submission of a pre-market notification application, called a 510(k). Any manufacturer marketing a product requiring a 510(k) in the U.S. has to have shown the product is the equivalent to a product that the FDA has already cleared for marketing domestically. Only materials for which manufacturers have completed an FDA pre-market notification 510(k) should be used in dental prostheses.
Dental laboratory experts say there are many excellent dental laboratories overseas. For them, the savings isn’t incurred through raw materials, but lower labor costs. DENTSPLY opened an FDA registered dental laboratory—Prident—in China in 2006. The dental laboratory materials used there are the same materials cleared by the FDA, supplied by DENTSPLY and sold to its U.S. laboratory customers, according to Arlo King, director of technical education for DENTSPLY Prosthetics, and Charles Pigott, vice-president quality assurance and regulatory affairs.
“We can trace any raw materials we use through the lot and case number,” King said. “Dentists should know their lab partners well enough to know if they ask for this kind of information the lab can provide it.”v
This article was provided by ADA News. |
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