Managing Dentin Hypersensitivity in the Practice

Brännström's hydrodynamic theory explaining why exposed dentin causes pain, how to distinguish hypersensitivity from other causes of dental pain, and which professional and at-home desensitizing agents are available today.

Dentin hypersensitivity is clinically described as sharp, short-lasting pain triggered by non-noxious stimuli — thermal, tactile, evaporative, chemical or osmotic — that resolves quickly once the stimulus is removed, without being attributable to any specific dental pathology or defect. The most widely accepted pathophysiological mechanism today is the hydrodynamic theory, proposed by Brännström in 1972: when dentin is exposed and dentinal tubules are patent, external stimuli cause movement of the fluid contained within the tubules, which mechanically activates pulp nerve endings and generates the pain sensation.

Two concurrent conditions are needed for hypersensitivity to occur: loss of protective enamel or exposure of the root surface (typically from gingival recession), and patency of the dentinal tubules — meaning they are not already occluded by smear layer or natural mineral deposits. Among the most common risk factors are overly aggressive brushing technique or use of hard-bristled toothbrushes, exposure to acidic drinks and foods, gastroesophageal reflux or recurrent vomiting behaviors, and periodontal treatments themselves, which can expose root surfaces previously covered by gingival tissue.

Clinical management of hypersensitivity operates on two levels. Home treatment relies on desensitizing toothpastes, mouthwashes and gels for daily use, with active agents such as potassium nitrate — which reduces the excitability of nerve fibers responsible for pain transmission — or compounds that physically occlude the tubules such as stannous fluoride, calcium and strontium salts, arginine or biomimetic nano-hydroxyapatite, the latter able to bind to dentinal apatite and collagen fibrils, stably occluding the tubules. Patients should always be told that these products require consistent use for at least 2-4 weeks before producing noticeable benefit: an expectation of immediate relief often leads to early treatment abandonment.

In-office professional treatment includes higher-concentration varnishes, gels and sealants applied directly to sensitive areas, often with dedicated trays for controlled, sustained exposure, as well as more specific treatments such as iontophoresis (which uses an electric current flow to facilitate diffusion of fluoride ions into the tissues, with immediate but typically no more than six-month benefit) or laser use in cases more resistant to conventional topical treatment. In all cases, before starting desensitizing treatment, an accurate differential diagnosis is always necessary, because other conditions — early caries, leaking restorations, enamel fractures — can present with clinically overlapping symptoms.

On Oralzon you'll find desensitizing toothpastes, gels and varnishes for both home and professional use, with different formulations based on potassium nitrate, stannous fluoride and nano-hydroxyapatite.