"FDA believes that exposure to lead should be reduced whenever possible. However, based on a
preliminary exposure assessment, FDA does not believe that the levels of lead found in these crowns
pose a significant public health risk.
"Due to the uncertainty about the rate at which lead is released from these crowns, the FDA
recommends studies to evaluate the rate of lead release from porcelain crowns under clinically
relevant and more rigorous extraction protocols in order to better assess potential health
effects.
"Lead causes cancer in animals, and there is some evidence of carcinogenicity in humans.
However, other symptoms of lead toxicity, such as neurocognitive and kidney damage, are usually of
greater concern than its ability to cause cancer.
"California EPA-OEHHA recognizes lead as a carcinogen under Prop 65 and has derived a No
Significant Risk Level (NSRL) of 15 ug/day to be protective of lead exposure after oral exposure
(January 2008). FDA estimates of lead released from dental crowns using very conservative
assumption of release are below this level. FDA laboratories will work with other government and
non-government entities to help assess how much lead a patient with ceramic dental work is exposed
to. Currently there are no universally-accepted, established protocols to determine the
bioassessibility of lead from these products."
