In many countries, the incidence of dental decay in the young is decreasing, and Hong Kong is no exception. However, there remains in the region, a number of restorative dental problems of some significance. These are tooth discolouration, fracture, and root surface decay. This article discusses these problems and the way in which their treatment is increasingly being undertaken by means of minimal-intervention adhesive techniques. The formulation of dental adhesive systems that are effective on a wet substrate has played a significant role in the development of modern dental practice. This development is briefly outlined, as are the principles underlying dental adhesion.