The subjective sensation of dry mouth or xerostomia is a common symptom and estimates of the prevalence vary from 10-50%. The Cochrane Collaboration published systematic of topical treatments for reducing the effects of dry mouth in 2011(Furness et al). Recently the American Dental Association’s Evidence-based Dentistry Center have published a critical summary of this review
The summariser notes that the review was of high quality, although, because of the range of interventions and variety of outcome measures only limited meta-analysis could be performed. The review included 36 trials in all, 17 of which were of high risk of bias. 18 of unclear risk leaving only 1 with a low risk of bias. Many of the trials also included only a small number of participants.
Overall the review found no strong evidence that any topical therapy is effective for relieving the symptom of dry mouth.
Furness S, Worthington HV, Bryan G, Birchenough S, McMillan R. Interventions for the management of dry mouth: topical therapies. Cochrane Database of Systematic Reviews 2011, Issue 12. Art. No.: CD008934. DOI: 10.1002/14651858.CD008934.pub2.