Implant failure due to titanium hypersensitivity/allergy?--Report of a case.

Six titanium implants were placed in the mandible between the left and right mental foramen of a 49-year old female patient. The implants were all constructed of the same grade IV titanium. Three types of implants were used, namely LIBB compression implant, cylindrical implant and Brånemark-like implant. These three types of implants were placed as part of a research project, which received approval from the ethics committee. The patient developed a severe reaction to all the implant units, with both clinical and radiological features of complication. The localised tissue reaction was severe enough to warrant removal of all the implants. The surrounding soft tissue was submitted for histological analysis, which revealed a chronic inflammatory response with concomitant fibrosis around all the implants as well as foreign body giant cell reaction around two implants. Following implant removal the patient recuperated well and the soft and hard tissue healed satisfactorily.