Sore and soft teeth are a manifestation of dentin sensitivity, which may also be caused by tooth decay. When the outermost enamel of the tooth is worn out, the inner dentin is exposed, and the dentin has small dentin tubes leading to the pulp tissue, so the tooth will feel sore and soft when eating hot and sour food. This is a manifestation of dentin sensitivity. Sour and soft teeth may also be caused by tooth decay, bacterial infection of the hard tissue of the teeth, causing the demineralization of inorganic material and decomposition of organic material. When tooth cavity appears, the tooth will be sour and soft when chewing food, and sometimes there will be slight discomfort, which is due to the bacterial infection is closer to the pulp tissue. Sour and soft teeth may also be caused by the loss of calcium due to eating too much acidic food, for example, like to drink carbonated drinks, or after eating hawthorn or lemon, it will lead to demineralization of teeth, and the teeth become sour and weak. Or if you do not brush your teeth in time after eating, food residue or soft scale accumulates around your teeth and gingivitis occurs, which can also cause the symptoms of sore and soft teeth. Therefore, sore and soft teeth are a manifestation of dentin sensitivity or tooth decay.