Zest MicroPrime G Gel Desensitizer · 4 mL

Dentin hypersensitivity is a short, sharp pain from exposed dentin in response to stimuli that are normally harmless: gentle touch, mild cold or heat, sweet or acid food and drink, and a blast of air. It is generally regarded as needing exposed dentin, especially open dentinal tubules, and a pulp nerve that responds to the outside environment. The most widely accepted explanation is the hydrodynamic theory: mechanical, thermal and chemical changes move fluid inside the tubules, which stimulates nerve terminals at the tubule walls and causes a brief acute pain. A review cited by the ADA puts dentin hypersensitivity at about 11.5 percent of patients.

Desensitizing agents work in one of two ways: they block the openings of the dentinal tubules, or they act on the pulp nerves directly. In-office products come as gels, solutions, varnishes, resin sealers, glass ionomers and dentin adhesives; at-home products are toothpastes, mouthwashes and chewing gums. The FDA has cleared fluoride varnish as a device for use as a cavity liner and a root desensitizer, to reduce sensitivity to temperature and touch on root surfaces exposed by receding gingiva. Silver diamine fluoride is classified by the FDA as a Class II device cleared for the treatment of tooth sensitivity, the same type of clearance fluoride varnish has, and must be professionally applied. Cavity varnish, a compound that coats a prepared cavity before the restorative material goes in, is a Class II device with special controls (21 CFR 872.3260).

Sources: Liu et al. 2020, Pathogenesis, diagnosis and management of dentin hypersensitivity: an evidence-based overview (BMC Oral Health) · CDC: Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States (MMWR 2001;50(RR-14)) · ADA Oral Health Topics: Fluoride — Topical and Systemic Supplements · FDA 21 CFR 872.3260, Cavity varnish · ADA Oral Health Topics: Toothpastes