Abstract: An extrasonic scaler includes a triangulate straight scaler, a leftward bent arc-shaped triangulate scaler, a rightward bent arc-shaped triangulate scaler, a leftward bent distal-hoe semi-triangulate scaler, a rightward bent distal-hoe semi-triangulate scaler, a leftward bent mesial-hoe semi-triangulate scaler, and a rightward bent mesial-hoe semi-triangulate scaler. Thus, the extrasonic scaler is designed according to the tooth pattern of the human body so that the extrasonic scaler can reach the deeper surface of the tooth root from various different directions to remedy the oral and periodontal diseases, thereby enhancing the working efficiency.