However, the oldest formulations of GICs were limited in success by their poor resistance to abrasion, low tensile strength and low final hardness. Glassionomer cements for dental restorations for this reasons acquired the label of cheap materials, not of high quality, especially useful for time-saving restoration, and more focused on social assistance. The advent of nanotechnology allowed in recent years significant structural changes in many dental materials, from impression materials to resin composites, and of course also for glassionomer cements, allowing in some cases to overcome physical limitations that are thought to be insurmountable. Thanks to this, the limits of hardness and resistance to stress of GICs have been exceeded, and today modern GICs can give an aspect of natural translucency and coloration to restorations, representing both a long lasting and also a valid aesthetic solution. Considering the evolution of GICs and their role as Biomimetic/Bioactive materials, and through the results of a multicenter clinical trial, the aim of this lecture is to show some new possibility of use, durability, efficiency, aesthetics and possible problems of a modern system based on a high-viscosity glassionomer cement, coated with a light-curable nanotechnological resin, when used for long-term restorations of teeth.