The Comparative Sensitivity of Intra-oral, in vitro, and Animal Models in the ‘Profile’ Evaluation of Topical Fluorides

Abstract

The development of predictive and rapid methods for the assessment of the anticaries activity of topical fluorides has been a longstanding objective of caries researchers. These methods can provide useful benefits in a number of applications, ranging from the identification of novel agents to progress into clinical testing to the regulatory screening of commercial product variations. In the latter applications, combinations of test methods (so-called profiles) are used by manufacturers to prove that changes in formulations do not alter the efficacy of the products. Historically, combinations of in vitro and animal models have been used for basic research as well as for profile testing purposes; however, in recent years, the use of intra-oral or in situ models has increased. In this paper, in vitro, animal, and in situ methods are reviewed in terms of the historical basis for their development, protocols currently used in testing, and the primary advantages and limitations of each as applied to ‘profile’ applications. Recommendations are provided concerning circumstances for the appropriate use of modern test methods in formulation screening.