Dentinal Hypersensitivity: A Review
Oxalate Strips

Dentifrices containing desensitizing agents have been the most popular first-line treatment for sensitive teeth, but there are some drawbacks. It typically takes time (approximately 4 weeks) to experience relief and on-going use is required to maintain the benefit. Recently, a novel oxalate strip has been introduced as a targeted treatment that provides immediate and durable relief. Moreover, obtaining relief from the strip provides the patient with a greater selection of fluoride dentifrice to include in their daily hygiene routine, including those with anti-plaque /anti-gingivitis efficacy that would benefit patients with recession due to periodontal disease.

Method of Action

Oxalate has been shown to have a significant desensitizing effect by physically occludingopen, exposed dentinal tubules with oxalate crystals. The oxalate crystals block fluid flow in the dentinal tubules, leading to decreased dentinal hypersensitivity.⁵⁵ Furthermore, oxalate crystals are relatively resistant to dissolution in oral acidic environments.¹⁴ Oxalates have been used in professional products for years. Efficacy results have been mixed, primarily because the performance of oxalate is dependent upon the formulation.^55-58

The most recent advance in oxalate products for immediate and durable relief has been the introduction of an over-the-counter thin, flexible strip coated with oxalate-gel (See Figure 7, Crest Sensi-Stop Strips, P&G). The strip targets the delivery of oxalate directly to the specific site of sensitivity. A strip is worn at each sensitive site for 10 minutes, applied half on the gingival tissue and half on the tooth surface of each sensitive site and worn for 10 minutes. Users report experiencing immediate relief that lasts up to one month. Additional sensitivity relief is typically experienced with additional applications (one per site per day).

Outside the United States, an oxalate-containing oral rinse has been introduced in certain markets. Sharma and McGuire investigated the clinical efficacy of a desensitizing mouthrinse containing 1.4% potassium oxalate (Listerine Advance Defence Sensitive) versus a negative control to determine relief of dentinal hypersensitivity. Results showed a reduction in dentinal hypersensitivity within a five-day period after multiple applications of the product.⁵⁷