Some people who use teeth whiteners may experience tooth sensitivity. That happens when the peroxide in the whitener gets through the enamel to the soft layer of dentin and irritates the nerve of your tooth. In most cases the sensitivity is temporary. You can delay treatment, then try again.
Federal prison. A federal prison is operated under the jurisdiction of a federal government as opposed to a state or provincial body. Federal prisons are used for convicts who violated federal law (U.S., Mexico), inmates considered dangerous (Brazil), or those sentenced to longer terms of imprisonment (Canada).
Jail. A building designated or regularly used for the confinement of individuals who are sentenced for minor crimes or who are unable to gain release on bail and are in custody awaiting trial. Jail is usually the first place a person is taken after being arrested by police officers.