Referral companies such as 1-800-DENTIST can be a helpful resource, though most dentists have an after-hours emergency number which may be given on their answering machine or by their answering service. Alternately, some hospital emergency rooms keep a dentist on-call for dental emergencies.
Some dentists offer after-hours services only for their existing patients, but others can be more accommodating in emergency situations. This varies from dentist to dentist, and sometimes the only way to find out is to call around local dental offices or to use a referral service. 1-800-DENTIST is a well-known Futuredontics company that helps pair patients with dentists. The number listed on the company's website for emergency services is 855-217-3840.
If a dentist cannot be reached, the American Dental Association recommends visiting a hospital emergency room. An emergency room doctor can prescribe medication to help with pain, and some emergency rooms even have an on-call dentist that can help in extreme cases.