What treatments have you found to be most effective in treating oral lichen planus?  

Agree, have had good response with oral tacrolimus solution. Patients can work in nystatin mouthwash or clotrimazole troches +/- chlorhexidine gluconate oral rinse 0.12%. Dexamethasone solution may be rotated with the tacrolimus if desired (I've just used the lower strength 0.5mg/5mL, dose: 10cc, sw...

1mg tacrolimus dissolved in 500ml saline or water at home switch and spit BID. Works very well in many cases and very safe.You can also add hydroxychloroquine 200 mg qd-bid.Aung-Din et al., PMID 30419108

I have also had success with apremilast swish and spit, and orally.

Agree re: tacrolimus solution as above. Oral metronidazole can work in approximately 20% of patients but is a nice option when it is effective. I prefer clobetasol ointment to TAC paste personally and have patients use dental trays for erosive gingivitis or strips of non-stick gauze smeared with clo...