The objective of this narrative review was to compare and analyze published articles on the mechanical properties of 3D printed fixed dental restorations compared to restorations fabricated with CAD/CAM and/or conventional milled composite and/or acrylic resins and to answer the following research question: Do 3D printed posterior restorations have increased flexural strength compared to restorations made of composite resin and/or acrylic resin? Articles were searched using the following electronic databases: PubMed, GOOGLE SCHOOLAR. This literature review was structured based on the guidelines given by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The PICO/PECO (Participant, Intervention/Exposure, Comparison, Outcome) focused question was: "Do restorations printed on 3D printers (I) for the posterior sector (P) have higher flexural strength (O) compared to restorations made of composite resin and/or acrylic resin (C)?". Of the two hundred and thirty-five titles, which were recognized after a primary search, fourteen articles were included in the analysis. The evidence available after performing this narrative review indicates that 3D-printed posterior fixed restorations have comparable mechanical behavior to CAD/CAM-engineered posterior fixed restorations in terms of flexural strength.