Most toothaches after a cleaning are dentin sensitivity, which usually subsides after a period of time. Dentin sensitivity is a common reaction of many patients after scaling. When enamel or bone is lost and dentin is exposed, dentin tubules can directly transmit external stimuli such as hot, cold, and tactile stimuli to the pulp, thus causing sensitivity. Scaling is the use of mechanical means to remove tartar and other irritants, inevitably leading to the loss of some of the dentin or even dentin, especially the ultrasonic work tip rests on the surface of the demineralized teeth, which will cause the patient’s sensitivity symptoms. Generally after a period of time will be relieved. If the toothache is not relieved for a long time after scaling, it is recommended to go to the hospital in time.