Having dry mouth is always troublesome, one of the effects of it is rampant decay. It is because saliva acts like a buffer and it reduces acidity bacteria producing as well as it carries mineral needed for replenishment of tooth surface. Saliva forms a film on tooth surface and protects it against loss of mineral too. One the reasons for getting dry mouth is medicines. We can always ask our pharmacist if this is the case and if so, we can ask our doctors if there is an alternative drug to take, one which does not cause dry mouth. The other one is systemic diseases like diabetes or HIV infection as well as autoimmune disorders such as lupus. Suggested protocol for dentists and patients for preventing tooth decay caused by dry mouth is as follows according to an article printed on Journal of Canadian Dental Association 2011;77:b85:
” Using remineralization paste and chewing gum containing Recaldent to replenish calcium and phosphate ions Using high-fluoride varnish once every 1 to 3 months to reduce the susceptibility of enamel to acid challenges Using high-fluoride-containing toothpaste and rinse daily, with monitoring for signs of fluorosis and patient compliance Chewing xylitol gum up to 5 times a day for 5 minutes each time to reduce acid production by bacteria, and increase saliva and oral comfort Taking medications, including pilocarpine, bethanechol or Sialor, to induce salivary flow and increase comfort for those with residual salivary gland function Using products made by Biotene for comfort and possible anti-bacterial activities Brushing teeth carefully to remove any plague and residual food particles with either a manual brush or and electric brush with an oscillating and rotating head, and possibly using a Waterpik to replace floss, as patients prefer Changing to a diet low in sugar and acidic drinks Potentially using chlorohexidine in conjunction with these other procedures Having the patient sleep with a remineralizing agent (e.g., MI Paste, X-Pur) in medication carriers fabricated like bleaching trays to extend exposure to the agent to keep the mouth wetter at night and to provide a mechanical barrier to an acidic environment.”
I hope this helps.