The cost of root canal treatment is different for anterior and posterior teeth, because the number of root canals in anterior teeth is generally based on a single root canal, so the cost of root canal treatment for anterior teeth is about 1000 yuan, and the cost of posterior teeth is a little more expensive than anterior teeth, about 1300-1500. The total cost of root canal treatment is about 2-3 times. If the patient is in pain from periapical infection at home, he can take some cold water orally, because the pain of periapical infection means that there is pus inside resulting in high pressure, so taking cold water orally can relieve the pressure and can temporarily reduce the pain, or he can take some painkillers orally at home to relieve the pain.