You need to take a dental film first to check whether the teeth are seriously corroded. If it is not serious, you can clean up the corroded place before filling the tooth. If it is serious, root canal treatment is needed. Look at the posterior molars. If it's a wisdom tooth, just pull it out. If it is a big tooth, it is recommended to treat it as soon as possible, because it has caused gingivitis.

Generally, a tooth filling costs several hundred yuan. If you need to make a root canal, it will cost about 2000-4000 yuan (the cost of the crown). By the way, I suggest you have your teeth cleaned.