Its a difficult issue to address because it depends on the frequency and duration of the bulimia. Oral hygiene with frequent brushing and flossing is very important to prevent the acid erosion that occurs with throwing up.
More importantly however is addressing the issue of anorexia and bulimia. There are other major health issues that need to be addressed as well. I suggest you post in the Anorexia/Bulimia/Binge Eating section in the Ask a Doctor forum to find out more. Sorry I don't particularly deal with it in terms of overall health.
I can only speak for myself. I had beautiful teeth when I was a teenager. Now from my twenties on....43, Infections!!!!I have had all my teeth root canaled, bonded, pulled, bridged, and now finally all pulled and I'm working on implants. Its not worth all the pain and suffering, I will tell you that right now. I have spent over 35,000 on my teeth over the years. Infections in the mouth can lead to death...the infection can go straight to your heart or brain. What you can do is not throw up. I wish I would have know this years ago!!!
Well it's not that easy to just stop...
I puked my way through high school and college, now I am 26 and facing four root canals, at $800 each, i'd rather be fat.