Restorative dentistry is a minimally invasive procedure. This motto was a particularly demanding target for many decades but could be reached much easier today due to the major improvements of most restorative materials: In case of layering composite restoration, we will focus on a rigorous spectrometric research studying the different opacities and translucencies of the current composite brands. Through this study and a classification based on opacity, we will propose an appropriate protocol that takes into account the thickness of the layers and the final value of the restoration.-In case of veneering indirect ceramic, today it is unacceptable to sacrifice sound enamel to create space for artificial restorative materials. Bonding techniques associated with novel laboratory techniques have significantly evolved, especially the capacity of new ceramics to mask dark areas even with small thickness. We will study, in a vitro investigation, the ultra-structure between enamel and ceramic in the less retentive cervical area and use this study as a basis for deciding on the design of the preparations in different clinical situations.