Whitening toothpastes with hydroxyapatite can whiten teeth but it doesn't whiten them in the way that you think it does. The type of whitening is very different but it can still work, just don't be disappointed that it doesn't do what you had in mind.
How hydroxyapatite toothpaste whitens teeth
Toothpastes with hydroxyapatite can whiten your teeth via two mechanisms:
Mechanical abrasion. Most whitening toothpastes utilize whitening abrasives which gently abrade away stains from the enamel surface. Since hydroxyapatite is a mineral, it is abrasive enough to remove stains while brushing with it.
Filling defects/porosities. Porosities, defects, nooks and crannies in the enamel can be filled in with hydroxyapatite thus smoothing over the surface. The enamel responds very well to it since it is biomimetic. Human enamel is literally made of hydroxyapatite!
We wish to expand upon the second point because it's quite interesting.
Hydroxyapatite is white in color such as in the example photo below.
Essentially when you brush with hydroxyapatite, it fills in all of the enamel imperfections and that can make the teeth appear whiter. Since the material itself is white, it gives the optics that the teeth have been "whitened."
Studies have shown that this type of whitening using hydroxyapatite based toothpastes does make the surfaces of the teeth feel smoother.
It's not the same as professional teeth whitening
Unfortunately, the hydroxyapatite type of whitening is NOT the same as professional teeth whitening since they are completely different mechanisms. One works through chemical means while the other utilizes mechanical means.
Professional teeth whitening is chemical based: Teeth whitening at the dentist typically involves the use of hydrogen peroxide or carbamide peroxide.
Peroxide-based whitening will chemically bleach the teeth by breaking conjugated double bonds of stain molecules.
This type of whitening is similar to bleaching a stained white t-shirt.
Hydroxyapatite teeth whitening is mechanical: The type of whitening with this toothpaste ingredient is more mechanical or physical in nature.
It can abrade away stains via a brushing action.
It can also fill in enamel defects and make it appear whiter.
This type of whitening is more similar to scrubbing a dirty dinner plate with a sponge.
In summary, these are two very different types of teeth whitening so you should adjust and temper your expectations if you're using it as a "whitening toothpaste." Yes, it'll make your teeth appear whiter but not in the way that you're probably thinking of.
Our Recommendation
Our dentists in Long Island City think that using hydroxyapatite whitening toothpaste is a solid choice as an everyday dentifrice. It'll remove stains, desensitize teeth, and even prevent cavities.
However, if your yellow teeth are stubborn and don't seem to be getting whiter despite a month or two of use with this toothpaste you should seek professional help. In other words, you should schedule for either an at home professional teeth whitening kit or getting an in office bleaching session.
The type of tooth stains that you have are probably not extrinsic and they're most likely intrinsic. These discolorations will not come off with just using whitening toothpaste!
