Universal cements: dual activated and chemically activated<br /><br />The clinical success of indirect restoration procedures<br />depends among others on the cementation technique<br />used to create a stable bond between the restoration<br />and the different dental structures. Resin cements<br />have been widely used in the fixation of inlays, onlays,<br />crowns and pins due to their improved mechanical<br />properties, ease of use and esthetic qualities.<br />However, many new products have appeared in the<br />dental market, making the choice of materials a difficult<br />task for professionals.<br />Resin cements are composed of a matrix of Bis-<br />GMA or UEDMA, monomers with a low molecular<br />weight, such as TEGDMA, and functional hydrophilic<br />groups that promote adhesion to dentin, such as<br />HEMA and 4-META Resin-based cements may<br />contain the monomer MDP (10-methacryloyloxydecyl<br />dihydrogen phosphate), which also promotes adhesion.<br />Adhesive cementation is a critical phase that<br />involves the application of an adhesive system and a<br />cementation agent. Consequently, this slow, sensitive<br />and complex procedure requires multiple steps.<br />Universal cements, which involve a process of dual<br />polymerization, have recently been launched in the market. However, the use of a multimode adhesive<br />system is recommended. These adhesives can be<br />applied to enamel and/or dentin, offering the possibility<br />of using them as a conventional (complete conditioning<br />technique) or self-etching system. These<br />systems differ in relation to the availability of the<br />monomer MDP, which interacts chemically with the <br />hydroxyapatite of dental tissue.