Teeth difficult but not painful may be the emergence of dentin sensitivity, commonly found in wedge-shaped defects, cryptocleidosis, excessive tooth wear, specific recommendations to the hospital for examination. 1. Wedge-shaped defects. Concentration of dental stress or brushing across the teeth may cause wedge-shaped defects in the neck of the teeth, may appear to suck the wind with a feeling of soreness and discomfort, found in the mouth with a neck defect. 2. Hidden cracks in the teeth. When biting hard objects or impacted by external forces, teeth can appear cracks, cracks reach the dentin, into the food may appear weakness and soreness. 3. Excessive wear of teeth. When the teeth are overly worn, the occlusion can be reduced, which will cause the upper and lower chewing joints to be sore, and eating hot, cold, sweet and sour food is sensitive and uncomfortable. Difficult but not painful teeth, it is recommended to go to the hospital for oral examination to determine the cause of the timely treatment.