Based on things I have read on AS gum problems are a part of the side effects. And my dentist agrees. I have two friends here in AS that have lost all of their teeth.
Also when I had a tooth extracted this year, I asked the dentist about the fact I have a water pik, braun toothbrush, I floss. Everything the normal person does to promote healthy teeth and gums. With me none of that prevents the AS from doing it's thing.

So if you have AS and you start to have dental problems the chances are it is AS related.

Hope I answered you question.

Doreen