They were sensitive right away. So I went back and the dentist "adjusted" them as best he could, but they're still sensitive. He claimed he had no idea why and that he had never seen anything like it. So I still favor the right side somewhat. It might have been the sealer he used or something. He did the right side a year or two later and they are fine. Sometimes I think that its a matter of waiting for the techniques and materials to evolve...and/or for them to come to a dentist near you. Next week I take the "next step" (finally) and am having a root canaled front tooth extracted and cleaned out; and 2 nickel crowns replaced with a metal-free bridge. I'm convinced these toxins (mercury, nickel, palladium, bacteria from root canals etc) have no place in a person's mouth.