Lead health hazard in root calan filling material

It has been stated in the recent literature that the lead content of N2 endodontic filling material poses a hazard of lead otxicity to the patient. No clinical evidence in humans was offered in support of the statements. In the studies here reported, it was determined that endodontic fillings of RC2B, A U.S. variant of the N2 material, contain, per root-canal, a quantity of lead equivalent to permissible uptake of 10-15 days. It is believed lead is generally unavailable to the blood stream, due primarily to its being chemically bound, and secondarily to the known affinity of dentin for lead. It was found that the levels of lead in the blood of nine young male patients, sampled at intervals up to 90 days following placement of RC2B endodontic fillings, were mostly nondetectable, did not exceed 9 mug/100 ml in any instance, and were all far below the accepted hazard-indicating level of 40 mug/100 ml whole blood.