Dr Marshall Webb (1844-1883), author, lecturer, debater, clinician, inventor, and dentist extraordinaire, was a decade ahead of others in putting forth a concept of 'extension for prevention.' One hundred twenty years ago, he was one of the best known, most advanced, and highly regarded dentists in the world. His pioneering work in cariology, preventive dentistry, ethics, and prevention of recurrent decay raised the standards of what we call operative or conservative dentistry, but he is almost unknown now. However, his concept of conservative tooth preparation could be applied today.