Have you thought of getting a second opinion from another dentist? The problem you have with a funny taste could be related to a lot of different things,(medications,etc.).It is extremely unfair to you and the 2 dentists that have treated you to try to get a diagnoses to your problem by someone who-A.doesn't have a pre-op and post-op x-rays of the tooth involved. B.Hasn't done a clinical exam of your mouth and the tooth involved. C.doesn't have a full medical history of you. Any guesses from this end are simply that----guesses and are likely to cause you more anguish and anxiety than you need right now.