I had a root canal about a year ago. I just noticed that it made my teeth shift. I thought it was too tight before but it was the second time I had it done because the first one cracked and had enough of the dentist. I didn't realize it would cause this. Does anyone know if my Dentist has any responsibility for this and how much a retainer costs. It's not a massive amount but enough to bother me a lot. Any info would be appreciated!