PubMed ID (PMID): 33969973Pages 168-184, Language: EnglishChiodera, Giuseppe / Orsini, Giovanna / Tosco, Vincenzo / Monterubbianesi, Riccardo / Manauta, Jordi / Devoto, Walter / Putignano, AngeloThere is a continuing increase in demand for the direct restoration of posterior teeth with resin-based composites. However, the execution of these restorations, especially the reproduction of the anatomical details of the tooth, still presents difficulties for most clinicians. Nowadays, resin-based composite restorations have become increasingly popular due to the development of new materials and filling techniques. Direct composite restorations are usually performed using the time-consuming incremental filling technique, which minimizes polymerization shrinkage. With this technique, the composite is built up in individually cured increments. Due to the superior physical and chemical properties of the newer bulk-fill composites, it is possible to replace this incremental filling technique with a more time-efficient bulk-fill technique, whereby the composite is placed and modeled in a single layer up to the occlusal surface. This article presents this novel technique for direct posterior composite restorations. The technique, called Essential Lines, is simple, esthetic, and time saving. It combines the advantages of the bulk-fill technique with a modeling technique that utilizes minimal so-called diagram lines to restore the tooth anatomy. This procedure can be used by beginners and expert practitioners alike in various clinical situations to produce direct posterior composite restorations with optimal function and esthetics.