Umbrella review on the management of xerostomia and hyposalivation - what evidence do we have so far?

Background and Objective: Dry mouth is a rather prevalent oral manifestation of the older population. Pharmacological and non-pharmacological alternatives have been assessed to manage it, its symptoms and consequences. This umbrella review characterized the synthesis of evidence about the alternatives to manage xerostomia and hyposalivation. Methods: We searched for systematic reviews of interventions to manage dry mouth in Cochrane Database of Systematic Reviews, EMBASE, PubMed, Prospero and DARE databases (up to September 2023). References were managed and selected by reading titles and abstracts using Rayyan QCRI. Selection of studies, data extraction and methodological quality assessment (AMSTAR 2) were conducted independently, in duplicate. Data were extracted to a previously tested form that included information about dry mouth causes, interventions, outcomes and results. Results: The research strategy generated 3,323 records. At the end of the selection process, 48 studies were included and had their data extracted. Pharmacological management methods such as Pilocarpine and Cevimeline Hydrochloride continue to be the most used methods, however, indicated with caution because of the adverse effects. Non-pharmacological methods such as acupuncture, electrostimulation and surgical transfer of salivary glands are promising, but better conducted studies are needed for indications in clinical practice. Salivary substitutes and stimulants mostly acted as moisturizers and some as saliva stimulants, with short-term effect. More than 80% of the reviews were appraised as ‘critically low’ quality. Conclusion: Well-designed and well-reported systematic reviews are still needed to increase the level of evidence on dry mouth management methods.