Inclusion Criteria:

1. High risk of oral cancer as defined by a twenty-pack/year cigarette smoking history or equivalent and is either a current smoker or has quit smoking within the last 24 months. Twenty-pack/year equivalent is defined as ½ pack/day for 40 years, or one pack/day for 20 years, or 2 packs/day for 10 years, or 4 packs/day for 5 years. AND/OR;
2. Ten-year history of twenty orally-consumed alcohol units/week and is either a current drinker or has quit drinking within the last 24 months. Twenty orally-consumed alcohol units/week is defined as the equivalent of twenty - 1 ounce shots of whisky or spirits/week (20 ounces = 600 mL), or twenty - 3 ounce glasses of wine/week (60 ounces = 1800 mL), or twenty - 12 ounce glasses of beer/week (240 ounces = 7200 mL);
3. Male or female, at least 45 years of age;
4. Written informed consent.
5. Females of childbearing potential may be enrolled following a negative urine pregnancy test performed at the SE visit. Abstinence will be considered an acceptable form of birth control.

Exclusion Criteria:

1. History of oral cancer, surgery or biopsy for suspected oral neoplasm;
2. History of recent oral surgery, periodontal treatment, or oral trauma (<14 days) or current orthodonture (e.g., braces);
3. Known hypersensitivity to study drug or its analogs;
4. Active and uncontrolled infection or any other severe concurrent disease that in the judgment of the investigator would make the patient inappropriate for entry into this study;
5. Psychiatric disorders which would interfere with informed consent or follow-up;
6. Use of any investigational agent within previous 30 days;
7. Female that is lactating or demonstrating positive pregnancy test;
8. Patients in whom betel nut use/abuse has been reported within the past 5 years;
9. Patients currently taking medication containing prohibited dyes.