I had 4 veneers on my front four teeth for 28 years. Replaced 10 mo ago. Each one eventually fell off... # 7 and 10 fell off 4x. Each time etched and took off a little more of my teeth. Finally redid all #7 and 10 popped off in first week. He said he"bonded" then cement them now Is that common? Prior to this 2ND replacement he took off a lot more from the sides.They don't look anything like my old teeth but rather like nubs now.Is there a possibility there's not enough tooth or enamel left?