Slight bulging of the gums during root canal treatment without pain can be observed, or oral antibacterial drugs. Root canal treatment period, due to the development of the disease will appear gum bulging, that is, the inflammation within the root of the tooth is more serious, the infection breaks through the mucous membrane to the outward discharge of pus, in the period of dental treatment is normal, you can observe, regular follow-up to change the drugs in the root canal. If the inflammation can not be self-absorbed or aggravate the symptoms, you can take oral antibacterial drugs, such as cefixime, amoxicillin, metronidazole and so on. After root canal treatment, the infection in the root of the tooth is completely removed and the gums will return to normal. Therefore, during the root canal treatment, there will be a slight bulging of the gums without pain, it is recommended to seek medical attention, under the guidance of the physician to choose to observe or take medication for treatment.