Hi thanks for contacting HCM... Dry mouth can be by many causes like certain drug like antihistaminic drugs.... Dehydration , sjogren syndrome , nerbve damage can lead dry mouth..... Drink more water to maintain moisture in mouth.... Fluoride tooth paste used. Sugar free gum chewing useful.... Breath through nose as through mouth breath dry ness can occur.... Room vaporizer can used. If still needed artificial over the counter saliva substitute useful..... At night time avoid more water drinking for preventing frequent urination at night... Avoid stress as they can lead excess urination... Take care..... Dr.Parth