So I think I am finally getting my head around this.

Once you get pain in your tooth and it requires a root canal that is the 1st point of infection. The root canal helps the infection but does not actually get rid of the infection completely. So all teeth that are root canaled are 'infected'. The problem is when the pain re-starts - that means thats the infected tooth has become 'abscessed'?

So a tooth can be infected for years and years and nobody notices? Its just in an x-ray that you notice. It is then basically a wait and see game to see if it develops into an abscess? So effectively If i have no pain but know that it is 'infected' I could be waiting months before it actually 'abscesses?'