Ultrasonic toothbrush

Abstract

Apparatus for use in personal dental hygiene care comprising an elongated member formed at least in part of a piezoelectric member with a pair of contacting surfaces intermediate the respective ends thereof with a brush member adapted to be received within the human mouth and moved across tooth and gingival surfaces and extending from one end of the elongated member. A casing adapted to be held in the hand is provided and is of a length at least equal to the piezoelectric member and having an elongated bore adapted to receive the piezoelectric member of the elongated member therein. Sealing means in the bore to engage the elongated member in readily releasable and in a fluid-tight fashion is used. Electrical contact means contained in the casing for releasable engagement with the contacting surfaces of the piezoelectric member of the elongated member is utilized so as to obtain electrical contact upon the insertion of the elongated member within the bore and disengagement of the electrical contact means upon removal from the bore of the elongated member. Generating means to supply alternating electrical signals to the contact means to establish an alternating field for transmission from the contact means to the piezoelectric member is provided whereby mechanical vibrations at the frequency of the alternating signals are induced in the elongated member and the brush member.