As some others have said, there is some evidence that links WLS to dental issues. The current thinking is that most issues arise from 1) increased incidences of vomiting, and 2) vitamin deficiency. To combat these, make sure you are not eating foods that cause dumping, listen to your full queues so as not to overeat, take your vitamins, and maintain good oral hygiene. It is wholly preventable, but it does take some work on your part.