Technological innovations are crucial for the advancement of the art and science of clinical dentistry. While some innovations suffer a lack of support, resulting in general nonacceptance, others are gradually adopted and supersede previous techniques and/or materials. Very little has been published in the dental literature concerning the reasons for the adoption, nonadoption, or rejection of new technology in dentistry. This paper reviews the diffusion of innovation in dentistry, with an emphasis on the adoption of rotary nickel-titanium endodontic instruments. Factors affecting adoption of new technology include a complex interplay of perceived benefits and advantages, and psychosocial and behavioral factors, in decision making. The importance of both dental school teaching and continuing education in dentistry is highlighted, emphasizing that such courses must be of a very high caliber.