The caries continuum: opportunities to detect, treat and monitor the re-mineralization of early caries lesions.

The aim of this review is to discuss dental caries as a dynamic process of de-mineralization and re-mineralization with progression, arrest or reversal of lesions reflecting the balance between them. The need for new clinical trial designs to assess oral care products which reflect and monitor these processes is highlighted and discussed. The research evidence to support the use of two state-of-the-art methods that focus on re-mineralization of natural root caries lesions and natural enamel lesions is described. The use of the Electrical Caries Monitor (ECM) in combination with clinical scoring of lesions to assess the hardness of root dentin and the use of Quantitative Light-induced Fluorescence (QLF) to measure enamel lesions are described together with a number of studies that have employed the methods to assess the efficacy of oral care products. It can be concluded that quantification of the re-mineralization provided by oral care products assessed using both buccal caries and root caries study designs is a valid approach to developing understanding of the mechanism of action of a new technology and to establishing its clinical efficacy in respect of arresting and reversing early caries lesions, and it complements, enhances and may ultimately supplant the information from a conventional two- to three-year clinical trial measuring effects at the cavitation level.