all dental work does damage. a crown is ok if the build up is natural tooth or composite and the crown itself has no metal in it. bridges are bad, especially on uppers because they will cause locking of the skull plates instead of the normal changes which will occur. the skull plates can be adjusted by a good chiropractor.
i had twelve fillings so i have a mouth full of damage. i have a couple of crowns to replace and a bridge to deal with. currently, i am trying to remineralize a tooth instead of doing any more drilling. i wish i had never seen a dentist in my entire life. they have ruined me in almost every way that is of human importance.