Dental Restorative Resin Composites: Modification Technologies for the Matrix/Filler Interface

Dental restorative resin composites are a pivotal class of organic/inorganic hybrid materials. The main reasons for their failure are secondary caries and dental composite fractures, which prevent their long-term service in posterior restorations. A remedy to these problems is improving the interfacial adhesion between the resin matrix and the fillers. Surface-modified inorganic fillers show strong potential as more than just a bond between these two phases and can therefore be considered a medium to compensate for the deficits of dental composites. This paper mainly discusses strategies to improve the interfacial adhesion of dental composites, including surface treatments of fillers with coupling agents, polymers, and tetraethyl orthosilicate (TEOS) coatings, as well as the selection of porous fillers capable of micromechanical resin matrix/filler interlocking. Additionally, the existing deficiencies of these strategies and the prospects for dental composites are discussed.