From Salivary Dysfunction to Prosthetic Challenges in Xerostomia and Denture Retention with Oral Gels

Xerostomia significantly compromises oral comfort, mucosal integrity, and denture retention. While topical therapies such as oral gels are commonly used to manage symptoms, their effectiveness remains limited due to an inability to replicate the complex biochemical and mechanical functions of natural saliva. This review explores the pathophysiology of salivary dysfunction, the structural and functional roles of mucins, and the tribological and rheological demands of the oral environment-particularly in denture wearers. Emphasis is placed on the interplay between mucosal surfaces, salivary films, and prosthetic biomaterials, as well as the importance of mucoadhesion and aqueous boundary lubrication. A rheological comparison of commercially available oral gels and whole human saliva (WHS) reveals that gels are significantly more viscous and elastic, yet fail to mimic the dynamic responsiveness of saliva. Current formulations lack functional standardization and labeling, limiting clinical guidance. The study proposes design principles for next-generation gels that incorporate amphiphilic, biomimetic components and measurable performance benchmarks.