Premolar and molar. Left-curve. First instrument for treating all the surfaces and the furcations. Maxillary:buccal and distal surfaces of sector 2, pivots at 13, then the buccal and mesial surfaces of sector 1. Mandibular:buccal and distal surfaces of sector 4, pivots at 43, then lingual and mesial surfaces of sector 3.
Torque wrench is essential to ensure scaler tips are attached to the handpiece at the correct torque.
Too much torque will damage the handpiece, too little torque and scaler tip will not work corecctly.