This is a question that occasionally does come up. Some patients have come to my New York dentist office with this complaint and have asked me to check whether the work in question was actually performed.
If a patient suspects that his insurer has been billed for work that has not been performed then if possible they should first contact their dentist and ask for an explanation. If not satisfied with the explanation, then it makes sense to contact the insurance carrier and let them know that some of the work submitted for was not completed or performed. Often the insurance carrier will contact the dentist and ask for an explanation or even ask him to refund the overcharged amount.
Some patients may not want to contact their dentist to ask for a clarification and in that case they may choose to contact their insurance company, especially if they are sure that the procedures in question have not been performed.