Ask the office staff how they handle emergencies that occur outside of the regular office hours. If the dentist has an answering service, ask how long it usually takes before he responds to a call placed to them.

Most dentists also arrange for a colleague to aid their patients when they are unavailable or on vacation. Ask the office staff the name of any other dentists that cover for your own dentist so you can check them out so you will be comfortable in case an emergency arises.