Hypnosis is becoming widely used in dentistry, especially in cases where side effects make the use of certain drugs problematic.
Fear of needles and involuntary gagging, both of which dentists encounter in the patients from time to time, respond extremely well to hypnotherapy.
In this a paper published in the American Journal of Clinical Hypnosis, and titled, Three Case Reports in Dental Hypnotherapy*, J. Arthur Weyandt D.S.S., describes case studies where hypnosis proved effective with dentistry patients.
You can read the paper here
* J. Arthur Weyandt D.S.S. (1972): Three Case Reports in Dental Hypnotherapy, American Journal of Clinical Hypnosis, 15:1, 49-55