Efficacy of gel-based artificial saliva on Candida colonization and saliva properties in xerostomic post-radiotherapy head and neck cancer patients: a randomized controlled trial

OBJECTIVE: To evaluate the efficacy of an edible artificial saliva gel, oral moisturizing jelly (OMJ), and a topical commercial gel (GC dry mouth gel) on Candida colonization and saliva properties. MATERIALS AND METHODS: This study was a secondary analysis of a single-blinded randomized controlled trial conducted in xerostomic post-radiotherapy head and neck cancer patients. Candida colonization, stimulated salivary flow rate (SSFR), saliva pH, and buffering capacity (BC) were measured at 0, 1, and 2 months after each intervention. Candida colonization was quantified by colony counts and species identified by Candida Chromagar, polymerase chain reaction, and API 20C AUX system. Statistical significance level was 0.05. RESULTS: A total of 56 participants in OMJ (N = 30) and GC (N = 26) groups completed the study. OMJ significantly increased saliva pH (p = 0.042) and BC (p = 0.013) after 1-month use, while GC only improved saliva pH (p = 0.027). Both interventions tended to increase SSFR but only GC had a significant increase at 2 months (p = 0.015). GC and OMJ significantly decreased the number of Candida species at 1 and 2 months, respectively. Both groups tended to reduce Candida counts but not significant. CONCLUSIONS: Both OMJ and GC saliva gels could improve saliva pH and decrease the number of Candida species. OMJ is superior to GC in its buffering capacity, while GC may better improve salivary flow rate. Long-term and large-scale study is warranted to test the efficacy of artificial saliva in oral health improvement. CLINICAL RELEVANCE: OMJ and GC gel could decrease the number of Candida species and improve saliva properties in post-radiation xerostomic patients. TRIAL REGISTRATION NUMBER: Clinicaltrials.gov NCT03035825. Date of registration: 25th January 2017.