Dental phobia is a fear, or phobia, traditionally defined as an irrational and exaggerated fear of dentists and dental procedures. Some controversy exists with regards to whether the fear is "irrational", as dental phobia is most commonly caused by previous bad experiences. Furthermore, there appear to be several subtypes of dental phobia, which to date have not been adequately described and categorized, for example "fear of dentists" versus "fear of specific dental procedures", needle phobia, and dental phobia resulting from previous, perhaps unrelated, abuse. Not all of these fears can be deemed irrational.

Dental phobia may better be defined as an extreme and persistent fear which results in the individual's avoidance of attending a dentist at all costs, unless possibly when a physical problem becomes overwhelming. Even thinking or hearing about going to the dentist will cause marked psychological distress, and the phobia may interfere with social functioning.

According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), dental phobia (which may also be referred to as odontophobia, dentophobia, dentist phobia, or dental anxiety) is one of the specific phobias. The diagnostic criteria of specific phobia include

• a marked and persistent fear of the specific object or situation that is excessive or unreasonable,
• an immediate anxiety response upon exposure to the feared stimulus, which may take the form of a panic attack,
• recognition that the fear is excessive or unreasonable,
• avoidance of the anxiety-producing situation,
• the phobia interferes with normal functioning or causes marked distress.

Dental phobia is most commonly caused by traumatic dental experiences, although there can be other causes as well. Children are often influenced by their parents' fears and attitudes towards dental treatment. Dental phobia may involve fear of dentists, dental procedures, a specific fear of needles, teeth, or objects and situations which remind the sufferer of the phobic situation. The dentist's drill is often a major factor in these fears.