@lindaadel in my experience, natural remedies did not work. Neither did going to dentists. I eventually was referred to an oral pathologist at a hospital dental clinic who first tried Nystatin oral suspension (ghastly stuff you rinse with, then swallow), which did nothing, then a Prednisolone rinse which didn’t work, and finally Lyderm (generic name Fluocinonide) gel, and about ten days after using that my mouth cleared up completely. I was told to stop using it then, and to use it only when the lichen planus recurred, which I do, once in a while now.

If you live in Canada you need a referral to an oral pathologist by your doctor. I don’t know if in the States you can just look up the name of an oral pathologist. If so, call and make an appointment. A referral to one known by your doctor or dentist may be better, however, if only because medical professionals know who is a good specialist.