Artificial salivas: present and future

Modern technology has allowed us to understand better the functions of saliva and now provides a rationale for developing: (1) diagnostic reagents for monitoring oral and systemic health status and (2) replacement therapies for individuals with salivary dysfunctions. Several areas of dental research are directed at augmenting or enhancing both the quality and quantity of saliva for individuals with dry mouth. An "intrinsic" approach is being explored which utilizes medications such as pilocarpine and bromhexine to stimulate the salivary glands to produce more saliva. An "extrinsic" approach proposes to use topically applied artificial saliva. Studies in our laboratory have been directed toward developing artificial salivas which incorporate many of the protective features of "native" saliva. An ideal artificial saliva should be "long-lasting", provide lubrication, inhibit colonization of microflora responsible for dental caries and gingivitis, and coat the oral soft tissues for protection against environmental insult and desiccation. Studies are currently under way to determine the structural requirements of salivary molecules responsible for these protective functions. Composite salivary molecules consisting of multiple biologically active or "functional domains" could then be designed and synthesized based upon primary sequence and conformational analyses, computer-assisted structural predictions, and in vitro testing. These supersalivary substances could then be used as saliva substitutes for targeting to selected oral surfaces to promote mineralization, hydration, and/or regulate microbial-mediated disease.