A radio frequency identification implanted in a tooth can communicate with the outside world.

A radio frequency identification (RFID) transponder covering the 13.56 MHz band was adapted to minimize its volume so that it could be placed in the pulp chamber of an endodontically treated human tooth. The minimized transponder had a maximum communication distance of 30 mm. In an animal experiment, the transponder was fixed in the cavity of a mandibular canine of a dog. An RFID reader positioned close to the dog's face could communicate with the transponder in the dog's tooth. In certain cases, the system is applicable for the personal identification procedures for hospitalized patients instead of an identification wristband.