Salivary hypofunction: An update on therapeutic strategies

Objective: To perform a literature review addressing the therapeutic strategies for salivary hypofunction. Background: Qualitative and quantitative salivary dysfunctions predispose to changes in the oral mucosa and teeth, cause impairment to oral functions and negative impact on quality of life. Materials and methods: A MEDLINE/PubMed search was conducted using the terms "Xerostomia" AND, "Saliva Artificial" OR, "Citric Acid," "Malic Acid," "Chewing Gum," "Acupuncture" OR, "Pilocarpine" OR, "Bethanechol" OR, "Cevimeline" OR, "Hyperbaric Oxygen Therapy" OR, "Stem Cell Therapy" OR "Genetic Therapy" and their Mesh Terms. Results: We selected 25 clinical trials investigating the effects of salivary substitutes, chewing gum, malic and citric acids, pilocarpine, cevimeline, bethanechol, acupuncture, hyperbaric oxygen therapy and regenerative therapies on salivary hypofunction. In most studies, the number of participants was low and the follow-up times short. The therapeutic modalities were classified according to the level of evidence on salivary dysfunction. Conclusions: Pilocarpine and cevimeline had the strongest evidence of beneficial effect on salivary hypofunction. Citric and malic acids increase salivary flow but also increase the risk of erosion and dental caries. There are no controlled clinical trials supporting the efficacy of acupuncture, stem cell therapy and gene therapy on salivary dysfunction, although clinical observations suggest a promising effect. There is no evidence supporting salivary substitutes, chewing gum, bethanechol or hyperbaric oxygen on the treatment of salivary hypofunction.