No one can tell you from LOOKING at any leukoplakia lesion if it is dangerous or not. It is however the MOST common pre cancerous lesion. So in my humble opinion the oral surgeon is a putz. Find a new guy. These white lesions can be removed by laser or incisional surgery. Your beta-carotene regime is not going to do anything, and published studies have shown this. The amount that you would have to take to match the positive response in animal models would not be healthy for you in other respects. It is common for smokers to develop leukoplakia, and sometimes upon cessation of smoking it may resolve on its own. Nevertheless, this is not something you should consider infinitely benign, and even if it was biopsied today and found to be so, it is not a stable lesion type and can convert to a malignant lesion at any time in the future. Try to have it removed. Hope that it does not return. If it does, have it biopsied on a regular schedule. Even this is a hit and miss idea. What part of the lesion might go malignant first? The left side, the right side, the center? Will the biopsy be taken at the exact place where the cells have gone to the dark side? Lastly, give up the tobacco permanently. It will only lead to something bad in the future.