Dentin Hypersensitivity

Dentin hypersensitivity (DH) is short, sharp pain from exposed dentin in response to cold, heat, touch, air, sweet or acidic stimuli. It needs two things at once: dentin that has lost its covering of enamel or gum, and dentinal tubules that are open. The most widely accepted explanation, the hydrodynamic theory, holds that these stimuli move fluid inside the tubules and that this movement stimulates nerve endings in the tooth. That is why treatments that plug the tubules or calm the nerve can work. Gum recession is the leading cause, followed by tooth wear from acid erosion, abrasion (for example from hard brushing) and attrition (for example from grinding). Periodontal treatment can temporarily increase sensitivity by removing the protective smear layer. Reported prevalence varies enormously, from about 1% to 98% depending on the population and how it is measured, with symptoms most common in the third and fourth decades of life and in women. Home treatment centres on desensitizing toothpaste used twice daily. A network meta-analysis of 125 randomized trials (12,541 patients) found most active toothpaste formulations beat placebo or fluoride alone, with calcium sodium phosphosilicate, stannous fluoride, potassium and hydroxyapatite combinations among those that helped. Improvement is judged over 2 to 8 weeks, and a dentist should confirm the diagnosis because cavities, cracked teeth and gum disease can feel similar.

• •Sharp, brief pain with cold air or cold drinks
• •Pain when brushing or touching a tooth
• •Sensitivity to sweet or acidic foods
• •Pain that fades within seconds of the trigger ending

• •Gum recession exposing root dentin
• •Enamel loss from acid erosion, including reflux
• •Abrasion from hard brushing or abrasive toothpaste
• •Attrition from tooth grinding (bruxism)
• •Temporary increase after periodontal treatment
• •Developmental enamel or dentin defects

Exposed dentin with open tubules. Exposure comes from gum recession (periodontal disease, brushing trauma, orthodontic treatment, piercings), or from loss of enamel through erosion by dietary or stomach acid, abrasion and attrition, or from developmental enamel and dentin defects.