1. Which doctor should I see if I have a white patch?

You have to visit a Oral and Maxillofacial surgeon to get yourself examined.

2. Are all white patches dangerous?

Absolutely not. Some patches appear if you have taken scalding hot food. These disappear in some days. Another condition called as Aspirin burn is particularly common. Patients who are unable to tolerate a toothache often place an aspirin tablet near the affected area. This will cause a white patch as well, but there is no need to panic.