Abstract: An object of the present invention is to provide a method for regenerating tooth germ, and more specifically, to provide a method for regenerating tooth germ that enables the treatment of patients who have lost teeth or have had teeth damaged by dental diseases such as pyorrhea alveolaris or dental caries. The present invention provides a method for regenerating tooth germ by culturing tooth germ cells while giving mechanical stimulus to the cells, and a regenerated tooth germ.

Abstract: In an arrester comprising a characteristic element made up of a stack of a plurality of metal oxide resistors, parallelly connected capacitor and a linear resistor are connected between the characteristic element and ground, and voltage drop across the linear resistor is used to light a neon lamp or to operate an alarm device for detecting deterioration of the characteristic element. To protect the capacitor and the linear resistor at the time when the arrester operates, a nonlinear resistor may be connected in parallel with the capacitor and the linear resistor.