Instant and Lasting Relief Effects of Strontium Chloride/Potassium Nitrate Dentifrice on Dentin Hypersensitivity

A Randomized, Double-blind Clinical Trial to Assess the Instant and Lasting Relief Effects of a Dentifrice Containing 2% Strontium Chloride and 5% Potassium Nitrate on Dentin Hypersensitivity

The objective of the present study was to compare the effects of a commercially available dentifrice containing 2% strontium chloride and 5% potassium nitrate in a silica base, versus a control dentifrice, containing exactly the same ingredients apart from strontium chloride and potassium nitrate, on the instant and lasting relief of DH.

Dentin hypersensitivity (DH) is a very common complaint that occurs in the general population. The intensity of the pain can be minor to very serious, which may prevent one from eating or performing ordinary oral hygiene practices. The most accepted mechanism by which DH occurs is hydrodynamic theory, which suggests that pain-producing stimuli cause rapid movement of fluid within the dentin tubules, as a result the free nerve endings, at the inner ends of the tubules or the periphery of the pulp, are excited and DH occurs. According to this theory, one approach to treat DH is reducing dentin tubule fluid movement through occluding open tubules. Strontium chloride was the first tubule-blocking ingredient used in dentifrice about fifty years ago and since that time a paucity of clinical studies have been carried out to test its effectiveness on DH. The other approach is to reduce the pulp nerve excitability by depolarizing the nerve endings, in which the most widely used material is potassium salts. Although there is limited clinical evidence that dentifrices containing strontium chloride or potassium nitrate alone, as the major desensitizing agent, has an effect on reducing DH, no clinical studies have shown the effectiveness of a dentifrice containing both strontium chloride and potassium nitrate in a silica base on alleviating DH.

Inclusion Criteria:

• good oral and general health
• possessing at least two teeth (incisors, cuspids, bicuspids and first molars with exposed cervical dentin) with hypersensitivity on facial surfaces which satisfied a tactile hypersensitivity stimulus score of 10-50 grams of force (Yeaple probe) and an air blast stimulus score of 2 or 3(Schiff Cold Air Scale)
• provided informed consent and were available for the study duration

Exclusion Criteria:

• progressive periodontitis, with teeth that had extensive restoration, suspected pulpitis, caries, cracked enamel or that were used as abutments for removable partial dentures,
• had hypersensitive teeth with a mobility greater than one
• had received periodontal treatment including surgery during the last year
• had used any other anti-hypersensitivity dentifrice or taken part in any other clinical trial, used any desensitizing agents during the last three months, or allergic to the ingredients of the dentifrices were excluded
• pregnant or breastfeeding women
• had taken the following drugs during the last month: anticonvulsants, antihistamines, antidepressants, sedatives, tranquilizers, anti-inflammatory drugs or daily analgesics