THE DIFFUSION OF INNOVATION IN DENTISTRY: FACTORS ASSOCIATED WITH THE ADOPTION OF ROTARY NICKEL-TITANIUM ENDODONTIC INSTRUMENTS Peter Parashos BDSc (Melb), LDS (Vic), MDSc (Melb), FRACDS, FACD A thesis submitted in total fulfilment of the requirements for the degree of Doctor of Philosophy. January 2004 School of Dental Science The University of Melbourne