How Does Sensodyne toothpaste work?

Many different factors contribute to how teeth may become sensitive. In the end it comes down to the fact that the nerve in the tooth is becoming more perceptive to temperature change and may also be more sensitive to touch.

The anatomy of the tooth consists of enamel (the white) and dentin (the yellow). Dentin should not be visible when looking in the mouth, unless the gums have receded or the enamel is worn down to the dentin layer. Dentin consists of tubules which are similar to pores for the tooth. These tubules, are protected by a smear layer; the smear layer can be removed a few different ways:

– Whitening products tend to dehydrate the tooth and strip the smear layer; this is not permanent, but may cause sensitivity

– Dentin may be exposed by hard brushing or a hard bristled toothbrush, grinding or clenching can wear through the enamel, and by the loss of supporting ligaments from severe gum disease.

– If dentin is exposed, then acidic food products, acidic mouthwashes and hard brushing can wear through layers that protect the tubules.

According to the ‘Hydrodynamic Theory’ , once these tubules are exposed for whichever reason, their fluid acts like a conductor of sensation from the outside layer to the inside of the pulp.

Sensodyne and other toothpastes with the same active ingredients such as Colgate pro-sensitive relief, and Pro-namel by Sensodyne, contain a mineral called potassium nitrate which blocks up the tubules that are exposed. This does not permanently fix the problem, however; consistent application or brushing with one of these pastes 2-3 times a day will treat most sensitivity related symptoms.

One may brush with these pastes daily, or if there is only a localized area of sensitivity, you may apply a dab to that area, and let it sit for about 30 minutes without eating, drinking or rinsing. Do this 2-3 times per day and expect to feel a difference after about 1-2 weeks.

Below is a picture of the tubules and how sensitivity occurs:


Cherise Britt RDH