My oldest was a biter. Nothing, absolutely nothing broke her of it but time and lots of patience. I even got desperate and tried the biting her back. Did nothing but leave a bruise for me as a reminder I just abused my child. She still bit any time she was "triggered." I remember when I was a teach in the 2's class I had a little girl who bit when extremely excited. She just got so excited she didn't know how to release her excitement. So, I had a biting blanket for her. Whenever she'd get super excited she could bite it. It went everywhere with us lol. I wish I had been that smart with my oldest. Maybe look into getting her something like this, and explaining she may only bite this? http://funandfunction.com/chewy-wristbands-p-1654.html
That site has other options as well.