Heavy Abrasives – Whitening toothpastes rely on heavy abrasives to strip off stains. These abrasives also repeatedly strip off protective protein layers from your teeth reducing your their ability to resist acids and make them more sensitive. To avoid putting your teeth at greater risk for toothbrush abrasion, you should always select a low-abrasive toothpaste.
Erosive Ingredients – Many whitening toothpastes also contain calcium chelating agents like citric acids, citrate, pyrophosphates etc. that can be erosive to your teeth. Don’t be fooled by all natural whitening toothpastes that have the same ingredients under different names.