1. Background, definitions and locations of restorations

The development of viable solutions in the field of dental restoration has mainly been guided by the ease of implementation, availability and physicochemical properties of the materials studied. Silver-mercury amalgams, still used today, have significant drawbacks for patients, including toxicity, poor aesthetics and lack of adherence to dental tissues. Furthermore, the implementation of this filling material requires the sacrifice of healthy tissues in order to obtain optimal cavity geometry. The first aesthetic alternatives to amalgam were based on silicate cements; however, the latter suffered from several defects including their delicate implementation, their poor mechanical properties (not all), their oral solubility and poor adhesion; they were quickly abandoned. From 1930 onwards the use of resins in particular acrylic and/or methacrylic...