Dr. Cyril Tahtadjian
Might be a side effect of another drug
Usually mouth rinse and Sialogogues can be used to stimulate saliva as well as chewing gum and sometime Malic or ascot if acid
If you can find the cause that would help personalize your treatment
Is it related to surgery or cancer treatments?
In any case, if it is something that must simply be treated, there are many products on the market to help with salivary flow such as rinses, lozenges and gums. I think the best are those that are sweetened by XYLITOL. This is a sugar that bacteria in the mouth can’t metabolize or use to create the acids that cause cavities. There are other medications that can be prescribed to increase salivary flow, but these seem to have fallen out of favor. The other and most “low-tech” solution is just to keep water on hand and sip as necessary.
Dry mouth could be due to various reasons, some them are as follows:
1-Current medications you're taking
2-Autoimmune disease sjogren syndrome
There are some OTC artificial saliva substitutes available at most pharmacies in the dental section you can try, but I would recommend you see a dentist to make the right diagnosis.
I hope this answer helps.