Having a dry mouth increases your risk of mouth infections, gum disease, and dental cavities. If the White dry patches inside the mouth cannot be wiped off then it is a matter of some concern. Dry mouth can also be because of health conditions such as
diabetes, stroke, yeast infection, etc. My suggesstion would be if the white lesions cannot be scrapped off and if there is burning sensations as well then best is to consult a nearby dental surgeon immediately or video-tele consultation with a dental surgeon so that the lesion can be appreciated well and proper medications be prescribed.
Next Steps
Avoid hot and spicy food for sometime
Increase water intake. And if any history of areca nut/betel nut/tobacco chewing habbit, then to be given up strictly.
Increase
vitamin rich food.
And consult a oral medicine/dental surgeon immediately for proper diagnosis