Causes of root pain include: 1, acute pulpitis: mostly seen in patients with deeper caries, tooth pain is spontaneous, pain is aggravated at night, pain increases after thermal stimulation, and can radiate to the face, temporal and ear; 2, acute periapicalitis: due to the progress of acute pulpitis or trauma, the tooth is in continuous pain, with floating sensation, afraid to chew food; 3, acute periodontitis: the affected tooth not only has chewing pain and floating sensation, and has formed periodontal pockets and tooth loosening, gum tissue can appear repeated swelling and bleeding; 4, periodontal abscess: abscess formation when the pain is intense, abscess formation pain can be reduced or alleviated; 5, dental allergy: cold, hot, sweet, acid stimulation can appear pain, but the pain can disappear after the cessation of stimulation.