If you have severe toothache, infection or injury within your mouth or to your teeth you need to make an appointment with your dentist.
If it is out of hours their answerphone message may have information on what to do. If they do not have any out of hours information, or if you are not registered with a dentists call NHS 111 on 111 and they will be able to advise you.
View this NHS page about NHS dentists and finding one near to you.