Sour and soft teeth need anti-sensitivity treatment if it is caused by dentin sensitivity, or tooth filling treatment if it is caused by tooth decay. The most common cause of tooth soreness is dentin sensitivity. The outermost layer of tooth enamel has no sensory function and is a protective layer of tooth tissue. Once the enamel is worn away, the dentin inside is exposed, and there are many dentin tubules leading to the pulp tissue, so external hot, cold, sour and sweet will cause dentin sensitivity, resulting in sore, soft or painful teeth. In this case, anti-sensitivity treatment is needed. Fluoride can be applied to the sensitive area to seal the dentin tubules and isolate the nerve from external hot and cold stimuli. Sore and soft teeth may also be caused by tooth decay, bacterial infection reaches the tooth nerve and causes tooth soreness. In this case, it is necessary to carry out tooth filling treatment. The decayed part of the tooth is removed and the tooth is filled to isolate the external stimulation to the tooth nerve. It may also be caused by brushing habits, such as wedge-shaped defect of teeth caused by horizontal brushing, which may also cause tooth sensitivity and soreness. Resin restoration of the tooth can be performed. So sore and soft teeth can be treated with anti-sensitivity treatment or dental fillings.