A method of controlling a plurality of forwarding databases provided in an Ethernet bridge having a plurality of devices. It uses a device making it possible to form a circuit including a first probe electrode inserted into the root canal of a tooth, a second electrode in conductive contact with an oral mucous membrane, frequency-generating elements able to produce alternating electrical signals at a number of frequencies, and elements for measuring electrical magnitude of alternating signals in the circuit. The force converter converts a downwardly directed force into a chestward resultant, which depresses the sternum, and two belt tightening resultants. The inorganic luminescent layer has such strength against heat and any damage such that the inorganic luminescent layer can be formed by sputtering method.