The sooner you get this checked out, the better you will feel, no matter the outcome. Not all dentists are experienced or see much oral cancer. My son's dentist sent him to an oral surgeon for a biopsy which is the only way to tell for sure if it's cancer or not. It may just be the wake up call to quit smoking. My son was (and is) a non smoker and he was 33 when diagnosed with oral cancer. Hope everything turns out ok for you and that you get the good news you need soon!
Let us know what happens.

Anne-Marie
CG to son, Paul (age 33, non-smoker) SCC Stage 2, Surgery 9/21/06, 1/6 tongue Rt.side removed, +48 lymph nodes neck. IMRTx28 completed 12/19/06. CT scan 7/8/10 Cancer-free! ("spot" on lung from scar tissue related to Pneumonia.)