An electroluminescent element which comprises host materials and guest materials in a part of an electroluminescent layer, and which is superior in device characteristics such as luminous efficiency and luminous characteristics to those of the conventional electroluminescent element is provided. A current error module receives a second current flowing through the electric engine coolant pump measured using a current sensor and determines a current error based on a difference between the first current and the second current. The first and second portions are for being embedded in the jaw bone. Apparatus also has attaching means to anchor to heat conductive object, said attaching mean maybe a bulge thermal stub locked into cavity of heat conductive object.