Hi.. Welcome to HEALTHCARE MAGIC. I have gone through your query and can understand your concern.. As per your complain dry mouth also known as Xerostomia with a history of Rheumatoid Arthritis.. Dry mouth can occur due to a number of conditions like salivary gland dysfunction, nerve damage supplying salivary gland, mouth breathing,diabetes, oral infections like thrush and as you have RA that is an autoimmune disease Dry mouth can also be due to Sjogrens syndrome that is another autoimmune disease and manifest as dry mouth and dry eyes.. I would suggest you to consult an Oral Physician and get evaluated and along with a thorough clinical evaluation he can also advise you investigations as per suspected cause to rule out the exact cause of the problem and treatment can be planned accordingly.. As of now you can chew sugar free chewing gum and tart candies as it help in stimulating saliva flow.. Gargle with Biotene mouthwash.. Drink plenty of water.. Limit brushing your teeth to just 2 times a day as it has drying effect in mouth.. If you have mouth breathing problem mouth guards can be helpful.. Hope this information helps.. Thanks and regards. Dr.Honey Nandwani Arora.