Root canals are the only way to help keep your tooth longer once the nerve has died or the tooth is infected.
What is a root canal and why are my friends telling me not to get one?!
To understand why you may need a root canal, it is helpful to look at the picture of the tooth below. You can see the nerve is trapped in the centre of the tooth. When a nerve gets infected the bugs get right inside the nerve space of the tooth - generally the bugs come from your mouth. The infected nerve gets very irritated and swollen, but because it's trapped inside your tooth it can't swell properly like other parts of our bodies. That's why it can hurt so much!
Unfortunately, when a nerve dies, oral antibiotics (ones you swallow) cannot get inside the tooth to where the bugs causing the infection are. So the only way to clear up the infected nerve is to clean it out. This can be done by extraction, where your whole tooth is taken out, but if you want to save your tooth then the root canal is your only option.
Common things that cause a nerve to die are big cavities, getting a big filling, or if your tooth gets knocked. Sometimes the nerve can be painful and very sensitive while it is dying. Other times the nerve can die silently and the first you may be aware of any symptoms is at a much later time when there is already an abscess under your tooth. This abscess can cause pain while chewing or a throbbing pain that can be dull or really intense.