In the few cases where the patient will feel discomfort, I tell them. Surprisingly anxiety is reduced if a patient knows exactly what to expect. I can not stress enough how important it is to find a dentist you can trust and who is willing to do what it takes to relieve your anxiety. Some dentists may go over relaxation techniques with you. Others will play soothing music in the background or allow the patient to bring in a walkman and headphones.
Some dentists even have virtual reality goggles which the patient can wear during the procedure.
If your dentist is unwilling to discuss your anxiety or try things to help reduce your anxiety it is time to get a new dentist. Remember that an educated consumer is a less anxious consumer. Make sure your dentist explains each and every procedure you undergo. Good dentists usually have videos, pamphlets, or books explaining the procedures they perform. A good dentist will answer the questions you have thus lessening your anxiety.