Sir, Mr Mackay (BDJ 2008; 205: 295–296) is to be congratulated upon his unimpeachable success rate in root canal treatment, far beyond anything I could find in the published literature from so-called specialists. Perhaps this impressive end justifies his questionable means. I wonder though, given his disregard for the quality guidelines in treatment, as adopted by the British Endodontic Society, whether he has relevant criteria to judge success?