Effects of a Novel Formulation on Oral Biofilm, pH Buffering, and Gingival Health in Patients with Dry Mouth

Xerostomia and Its Cellular Targets

Xerostomia, the subjective feeling of a dry mouth associated with dysfunction of the salivary glands, is mainly caused by radiation and chemotherapy, various systemic and autoimmune diseases, and drugs. As saliva plays numerous essential roles in oral and systemic health, xerostomia significantly reduces quality of life, but its prevalence is increasing. Salivation mainly depends on parasympathetic and sympathetic nerves, and the salivary glands responsible for this secretion move fluid unidirectionally through structural features such as the polarity of acinar cells. Saliva secretion is initiated by the binding of released neurotransmitters from nerves to specific G-protein-coupled receptors (GPCRs) on acinar cells. This signal induces two intracellular calcium (Ca2+) pathways (Ca2+ release from the endoplasmic reticulum and Ca2+ influx across the plasma membrane), and this increased intracellular Ca2+ concentration ([Ca2+]i) causes the translocation of the water channel aquaporin 5 (AQP5) to the apical membrane. Consequently, the GPCR-mediated increased [Ca2+]i in acinar cells promotes saliva secretion, and this saliva moves into the oral cavity through the ducts. In this review, we seek to elucidate the potential of GPCRs, the inositol 1,4,5-trisphosphate receptor (IP3R), store-operated Ca2+ entry (SOCE), and AQP5, which are essential for salivation, as cellular targets in the etiology of xerostomia.

World Workshop on Oral Medicine VIII: Development of a Core Outcome Set for Dry Mouth: A Systematic Review of Outcome Domains for Xerostomia

OBJECTIVE

The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth.

STUDY DESIGN

A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized.

RESULTS

From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains.

CONCLUSION

There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

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.

Mouth-Watering Results: Clinical Need, Current Approaches, and Future Directions for Salivary Gland Regeneration

Permanent damage to the salivary glands and resulting hyposalivation and xerostomia have a substantial impact on patient health, quality of life, and healthcare costs. Currently, patients rely on lifelong treatments that alleviate the symptoms, but no long-term restorative solutions exist. Recent advances in adult stem cell enrichment and transplantation, bioengineering, and gene transfer have proved successful in rescuing salivary gland function in a number of animal models that reflect human diseases and that result in hyposalivation and xerostomia. By overcoming the limitations of stem cell transplants and better understanding the mechanisms of cellular plasticity in the adult salivary gland, such studies provide encouraging evidence that a regenerative strategy for patients will be available in the near future.