[Dental alloys and allergy. Case report]

The case of a 67-year-old woman, who had been wearing an upper partial removable denture with a cast metal framework made of CoCrMo alloy for years without any problems, is described. After the extraction of a molar tooth a nickel alloy retention was soldered to the framework. Following reinsertion allergic reactions appeared. The soldered joint showed considerable corrosion. After removing the retention and the soldered joint, the allergic reactions disappeared, although an epicutanceous test had revealed a positive reaction to cobalt. This case supports the high corrosion resistance and biocompatibility reported for CoCrMo alloys in the literature and the loss of these properties due to inadequate processing. Furthermore, the case illustrates a true allergic reaction. In contrast to the rather indiscriminate use of the term allergy to describe various vague disorders, this diagnosis should be restricted to clearly identified clinical situations.