Grind up a doxycyline tablet, put some on a denture adhesive and stick it on sore – one application doubles pain relief over time
Oral Surg Oral Med Oral Pathol Oral Radiol. 2013 Oct;116(4):440-6.
Single application of topical doxycycline hyclate in the management of recurrent aphthous stomatitis.
Vijayabala GS, Kalappanavar AN, Annigeri RG, Sudarshan R, Shettar SS
If patient had recurrent issues, could have several doxycyline tab dispensed and buy own Polident or something .Cheap and effective.