This is 1 guy who uses endocal with lasers and ozone and claims a lot of success. He also did a 3 year study and found none or possibly only 1 fracture(can't remember) out of some 70 or so teeth studied. The Goldberg study is the one that everyone cites and they used teeth that were extracted in a humidifier: not the same as teeth in the mouth!! Also, it's arguable whether the teeth are "dead" as the peridontal ligament- if healthy- makes the body act like the tooth is alive by many accounts.