The leading theory behind whitening treatment causing teeth sensitivity is that the sensitivity is caused by the slight weakening of tooth enamel during the whitening process. This exposes microscopic pores in your teeth called “dentinal microtubules,” which connect the tooth’s exterior enamel to the interior nerve, allowing us to feel sensation in our teeth. When exposed, the microtubules can become more sensitive to temperature and pressure.  The good news is, post-whitening teeth sensitivity is usually a temporary condition lasting only a few days. This is because your body quickly remineralizes the teeth, sealing up the dentinal microtubules, and returning them to their less-sensitive original state.