AbstractIn dentistry comparative studies of diffusion of disease preventive innovations are rare and usually atheoretical. For these reasons the present study was designed 1) to determine whether or not normal distribution assumptions applied to decisions to adopt caries preventive fluoride programs in a public dental service; 2) to compare rates of adoption of two school‐based and one clinic‐based fluoride program, and 3) to look for evidence indicating which type of decision‐making may have been involved. The programs studied were school‐based fluoride brushing 4–5 times per year, fluoride mouthrinsing at least once a month, and professional topical fluoride applications at least once a year. Data were collected by postal questionnaires from public dental officers in Norway in 1972, 1977 and 1982. To determine the length of time which had elapsed from the time of innovation of the technologies to adoption, the dental literature was reviewed. The adoption curves for school‐based fluoride brushing and rinsing, as well as for clinic‐based topical fluoride application did not comply with the normal distribution assumption. The time lapse from innovation to adoption was in excess of 10 yr and the rates of adoption differed between programs. Decision‐making would appear to have been primarily individual or collective. It was concluded that generalization beyond the innovations studied and the social and organizational setting of this particular investigation is inadmissible. Consequently, there is a need for more and larger scale comparative analytical studies to increase our understanding of diffusion and adoption of innovatio