Microscopy investigations. Techniques, results, limitations

This paper critically reviews current microscopy techniques that are used t o image resin-dentin interfaces and more in particular to investigate the p rocess of hybridization and resin-tag formation. A short description of the four most commonly used microscopy techniques with their necessary specime n-preparation methodology is provided along with a discussion of their poss ibilities, limitations and potential artifact formation. With this critical appraisal on microscopy techniques available to study adhesive interfaces, it is hoped to encourage the use of high-resolution analytical tools to fu rther elucidate the mechanisms of bonding at the ultra-structural level. Be sides ultra-morphologic characterization, more research should be devoted t o study the chemical and physical properties of resin-dentin bonds. The fin al objective of such fundamental research should be to establish a more dur able and reliable adhesive restorative technique.