Okay, a bit more Googling and I've discovered the following:
1. Getting rid of the infection is a matter of degree-it's not absolute. You will likely never get rid of every single cell of infection inside the tooth. This is partly cause you can't reach all the bacteria. Dentists use sodium hypochlorite (similar to bleach), laser and ultrasonic water tools to clean things out. It's now known fact that teeth are porous, and the teeth themselves can contain infected cells. The tubules of which the root is made up can be filled with bacteria. Claims are being made that newer types of lasers can clean out a large portion of the tubules. Nearby bone can also be infected.
2. Once you do a root canal, the tooth no longer has a nerve and blood supply to keep it healthy. Blood supply can provide immune system cells and lymph, and in reverse, a path through which the body can get rid of at least some of the infected cells/material. Take away the blood supply and the nerve, and tooth is not able to fend for itself as well against the (albeit lower after the canal) less infected tooth. The tubules are also a pathway for important body chemicals to travel which are used to fight infection.
3. It seems some of this depends on both the skill and completeness of the dentist's work. A well-cleaned root canal is less likely to get infected (or should I say more infected).
4. Some argue that Gutta Percha, the material used to fill the canal, is toxic, in various degrees. There's a lot of controversy about
whether this is true.
5. Substitutes for root canal, include a partial, a crown or an implant. Each of these has repercussions, and there is no ideal solution-it depends on your body and your situation.
Post Edited (Hogwild) : 11/21/2018 8:00:24 PM (GMT-7)