In the past, endodontic treatment was performed on very simple, selective and straightforward cas­ es – mostly anterior teeth and a few simple posteriors. Endodon­ tic surgical techniques were in

their infancy. Failing endodontically treated teeth were extracted, and retreatment was seldom attempted. Extraction of the tooth and replace­ ment with a bridge, if possible, was the norm. The standards for success­ ful endodontics varied widely. Universal criteria for endodontic suc­ cess did not exist. Clinicians, therefore, had few alternatives but to do the best they could under the circumstances and then “wait and see” if the treat­ ment rendered would ultimately prove successful.