Sensitive teeth can ruin your day, but the the usual recommendation (use desensitizing toothpaste) is a safe bet—right?
Desensitizing toothpaste is a common tool in our dental arsenal, but it’s important to understand how it works and what it actually treats. We all know that it makes hot and cold food more bearable, and it can mute inexplicable dental pain that doesn’t come from cavities, but that doesn’t make it a cure-all.
So what’s the real deal behind desensitizing toothpaste? How does it work? What does it treat? What doesn’t it treat? Let’s find out!
What Causes Sensitive Teeth?
There isn’t a single cause for sensitive teeth — it’s usually triggered by a combination of factors, and there’s a lot of individual variability. For some, it’s caused by worn enamel; for others, it’s largely genetic.
Importantly, sensitive teeth (or, to be more accurate, dentin sensitivity) aren’t the result of tiny cavities; the condition is caused by the excessive stimulation of the interdental nerves. These nerves exist deep inside your teeth and, barring extreme cavities or broken teeth, they’re only exposed to indirect level. How?
The leading theory on dentin sensitivity attributes it to hydrodynamic pressures inside your teeth. Your teeth aren’t solid bone; they’re built in layers, and the dentin layer, just beneath your enamel, is criss-crossed with tubules that contain dentinal fluid.
This fluid is normally insulated from pressure variations, but worn enamel, gingivitis, or genetic factors can change that by exposing the ends of the dentin tubules. These exposed tubules then transmit sensations from the oral cavity directly to the interdental nerves, causing acute pain and/or temperature sensitivity.
Dentin tubules are tiny, too small to be seen with the naked eye. This means that dentin sensitivity has to be treated somewhat creatively. In the next section, we’ll cover three common active ingredients in desensitizing toothpaste.
How Desensitizing Toothpaste Works
Desensitizing toothpaste is more than just ‘Tylenol for your teeth.’ Different ingredients address it through different mechanisms, but it isn’t a simple pain reliever. According to Ask The Dentist, there are three common active ingredients used in desensitizing toothpaste:
Potassium Nitrate and Strontium Chloride (or Acetate; they’re largely interchangeable) have been used in desensitizing toothpaste since the early sixties, and they’ve been researched extensively.
Potassium Nitrate desensitizes your teeth by hyperpolarizing the interdental nerves, increasing the stimulus threshold for pain and temperature signaling. This compensates for the increased stimulation caused by hydrodynamic pressure, without blocking normal day-to-day sensations.
Strontium Chloride, meanwhile, limits the nerve’s exposure to stimuli by blocking the tubules that lead to the interdental nerves. It does this due to the molecule’s structural similarities to calcium, which let it serve as a kind of “patch” over the exposed tubule.
Stannous Fluoride is a ‘newer’ desensitizing agent, but it works the same way as most other fluoride treatments: it forms a calcium barrier. This barrier is more permanent than one made out of Strontium Fluoride, and it also forms quicker. Notably, there are prescription-only desensitizing toothpastes that use Stannous Fluoride, which makes it a popular pick among patients experiencing more intense sensitivity.
All of these active ingredients rely on frequent, and consistent, usage in order to work and they take up to a month of use to be fully effective, although initial effects are often experienced sooner.
How to Address the Root Issue
If you’re finding that your teeth are becoming more sensitive over time, or that the desensitizing toothpaste that you’ve been using isn’t quite cutting it, it’s probably time to schedule a dentist appointment. Dr. Halsema can help you pick a toothpaste with higher concentrations of active ingredients, and may suggest other treatments — fluoride treatments, deep cleaning, etc. — that can make a significant difference.
Dentin sensitivity and cavities are separate issues, though, so don’t be surprised if the treatment isn’t a filling or a root canal. Some people are simply more sensitive than others, and there’s nothing wrong with using desentizing toothpaste as a general solution for sensitivity. It’s safe to use, it’s been around for nearly sixty years, and the ingredients have been extensively researched.
It’s worth emphasizing, however, that you can’t replace a dentist visit with desensitizing toothpaste. It can do a lot for pain and temperature sensitivity, but it can’t fix cavities. If your teeth hurt more than they used to, visit Dr. Halsema, not the drug store.