The possible causes of soreness and softness of the lower incisors are many, and the common ones are periodontitis, wedge-shaped defect, dentin allergy, caries, and physiological wear, as follows: 1. Periodontitis: Patients with periodontitis may experience alveolar bone resorption, gingival recession, and tooth loosening and displacement, which may cause soreness and softness of the lower incisors. 2. Wedge-shaped defect: Wedge-shaped defect is mainly caused by incorrect brushing posture or excessive brushing force, which may cause patients to have soreness and softness when eating foods that are too cold, too hot or high in sugar. 3. 3.Dentin hypersensitivity: Dentin hypersensitivity caused by excessive tooth wear can also cause soreness and softness in lower incisors. 4.Decay: Patients with decay can experience soreness and softness when they are stimulated by the outside world. 5.Physiological wear: Physiological wear is common in middle-aged and elderly patients and may lead to exposure of tooth roots, resulting in soreness and softness in teeth when eating. Sour and soft feeling when eating. Therefore, if the lower incisors are sore and soft, it is recommended to actively seek medical examination and carry out targeted treatment according to the specific cause.