Although the process of root surface caries is essentially identical with the process of enamel caries there are important differences that need to be recognised. In enamel caries the early lesion is identifiable as a white spot lesion because of the increased porosity of the enamel. The early root surface lesion may be very difficult to detect because there is no enamel so there is likely to be minimal or no colour change but only a modification in surface texture. The mineral content of dentine is much lower than that of enamel so the collagen matrix will be rapidly expose although it may retain much of its physical structure as long as it remains well hydrated. The exposed matrix is susceptible to physical damage, by a probe for example, but it can be readily remineralised through the repair mechanisms providing the disease is eliminated, and the demin/remin balance is stabilized. Advanced root caries lesions may therefore be rehardened through the application of topical fluorides or remineralising solutions and the progression modified or arrested. The enamel is generally not involved in the early stages but the lesion may extend up and under the cervical margin of the enamel crown if the lesion is allowed to progress.