What makes "Sensodyne" work?

[Equipoise]

My dentist told me to stop using my regular toothpaste (Aim) for a few weeks and just use Sensodyne when brushing my teeth. It's supposed to Relieve "Painful Sensitivity" which I at first took to mean that it's "less harsh" than regular toothpaste. But I read on the back...

"Do not use this product longer than 4 weeks unless recommended by a dentist or doctor."

So now I'm thinking it changes the teeth somehow to make them less sensitive. But how? And what happens if you use it for 6 months, or a year?

The ingredients sound fairly alarming. And it tastes nasty. And it burns when I try to swish.

POTASSIUM NITRATE (5%)
SODIUM FLUORIDE (0.15% W/V FLUORIDE ION)

What's the deal? Thanks in advance for any clues to what I'm putting in my mouth.

[HMS Irruncible]

Originally Posted by Equipoise

My dentist told me to stop using my regular toothpaste (Aim) for a few weeks and just use Sensodyne when brushing my teeth. It's supposed to Relieve "Painful Sensitivity" which I at first took to mean that it's "less harsh" than regular toothpaste. But I read on the back...

"Do not use this product longer than 4 weeks unless recommended by a dentist or doctor."

So now I'm thinking it changes the teeth somehow to make them less sensitive. But how? And what happens if you use it for 6 months, or a year?

The ingredients sound fairly alarming. And it tastes nasty. And it burns when I try to swish.

POTASSIUM NITRATE (5%)
SODIUM FLUORIDE (0.15% W/V FLUORIDE ION)

What's the deal? Thanks in advance for any clues to what I'm putting in my mouth.

The current understanding of tooth sensitivity is that the tooth, which is supposed to be a nonporous mineral matrix, for whatever reason erodes and has tiny channels that can transmit sensation to the nerve. The sensitivity paste has minerals that help "remineralize" the tooth and block these channels after several weeks of use.

If you got this sensitivity by scrubbing your gums until the roots are partially exposed, the sensodyne isn't going to help much though.

http://www.dentalgentlecare.com/sensitivity.htm

[WhyNot]

Pain, especially to cold things, can also be caused by exposed dentine - the inner substance of the tooth, which is covered by enamel. The enamel can get quite thin, especially where the tooth meets the root (at the gumline). The root is covered by a substance called cementum, which is easily worn away. Dentine contains little tunnels (tubules) that link to the nerves on the inside of the tooth, and when dentine is exposed, these nerves are easily stimulated, resulting in pain.

Desensitizing agents such as Sensodyne work by blocking off the tubules, so that the nerves don't get stimulated. Sensodyne doesn't work that well used as a toothpaste. It works a lot better by gently massaging it into the sore spot with a finger. Do NOT rinse it off with water or mouthwash. It may take several weeks before the desired effect is reached. Sensodyne can be used indefinitely. The warning on the US packet not to use Sensodyne for more than a month is a legal requirement, designed so that people won't put off seeing a dentist when something might be seriously wrong. There are no actual health reasons for not using Sensodyne long-term.

From DIY Dentistry.

[Nanoda]

I'm not sure why you're getting a 'burning sensation'. I'd recommend trying a different toothpaste - all the 'sensitive' toothpastes contain the same active ingredients in the same percentages. One of them might taste better for you. (And they'll probably be cheaper, too).

[Kalhoun]

I use it (all the time...my dentist said it's ok). But he told me to switch to Crest for Sensitive Teeth, as it is reported by most users to be better than Sensodyne.