Gum swelling and pain in the large teeth may be caused by gingivitis or apical infection, and the cause needs to be identified to determine the next treatment option. There are two causes of swollen and painful gums, the first is caused by gingivitis, not brushing in time after eating, food debris or soft scale gathered around the teeth, the gum tissue is in a congested state, over time there will be bleeding from brushing or bleeding from eating, the gums are red and swollen and overflowing thick, and painful symptoms appear. In this case, dental scaling, ultrasonic removal of tartar, followed by gum rinsing is required. Gum swelling and pain may also be caused by tooth decay, bacterial infection leading to pulp tissue suppuration and necrosis, inflammation without timely drainage, further breaking through the gums to drain pus outward, forming gum abscess or gum swelling and pain. In this case, root canal treatment is required to remove the abscessed nerve, followed by disinfection of the root canal of the tooth and finally a tight filling. A proper root canal treatment will prevent reinfection, remove the irritants in the root canal, and the inflammation of the gums will subside on its own. Therefore, swollen and painful gums of large teeth can be scaled and medicated, or root canal treatment can be performed to relieve the painful symptoms.