Dentin Hypersensitivity Zhang Qi Wuhan University School of Stomatology

Introduction

Definition: Dentin hypersensitivity is a common condition of transient tooth pain caused by a variety of exogenous stimuli.

Characteristic Short, sharp pain. Most in cervical, then occlusal

Stimuli The exogenous stimuli include: Thermal (cold) Tactile (touch) Osmotic changes (sweets, drying the surface)

Etiology The primary clinical cause is exposed dentinal tubules.

Two phases of development of dentin hypersensitity First, dentin has to be exposed. —lesion localization The dentinal tubules must be opened —lesion initiation

The most common clinical cause for exposed dentinal tubules is gingival recession.

Common Reasons for Gingival Recession 1.Inadequate attached gingiva 2.Prominent roots 3.Tooth brush abrasion 4.Pocket reduction periodontal surgery 5.Oral habits resulting in gingival laceration 6.Excessive tooth cleaning 7.Excessive flossing 8.others

Reasons for Continued Dentinal Tubular Exposure 1.Poor plaque control, acidic bacterial byproducts 2.Excess oral acids, sodas, fruit juice 3.Cervical decay 4.Toothbrush abrasion 5.Tartar control toothpaste

Mechanism Hydrodynamic theory —M.Brännström in 1967 The fluids within the tubule are disturbed either by temperature changes or physical osmotic changes. These fluid changes stimulate a baroreceptor which leads to neural discharge (depolarization).

Baroreceptor: a never receptor sensitive to pressure

Treatment A challenge for both the patients and dentists. It’s difficult measuring/comparing different patient’s pain. It’s difficult for patients to change the habits.

Treatment Strategies Plug the dentinal tubules preventing fluid flow. Desensitize the nerve making it less responsive to stimulation.

Nerve Desensitization Potassium Nitrate the only one approved by FDA and ADA KNO 3 penetrates through the dentinal tubules to the nerve; K + may depolarize the nerve and prevent it from repolarizing; Thereby, Preventing it from sending pain signals to the brain.

Covering Dentinal Tubules  Composite or GIC restoration  Crown placement  Periodontal surgery

Occluding Dentinal Tubules To plug the inside of the dentinal tubules Ions or salts: stannous fluoride, sodium fluoride, potassium oxalate, etc Precipitates: glutaraldehyde Resin: dentin sealers

Laser: another choice

Treatment Steps 1.Thorough exam to identify etiology and eliminate tooth fracture and irreversible pulpitis. 2. Potassium nitrate containing product/toothpaste 2×day for at least 2 weeks. 3. Potassium nitrate containing product in a tight fitting dental tray.

4. In-office tubule occluding product. 5. In-office tubule sealer. 6.Dental restoration, or a periodontal surgery, that covers the exposed dentin. 7. Endodontic procedure to remove the pulp.

The patient should be informed of the series of steps that may be necessary to eliminate the problem.