Full analysis of the effects of modeler liquids on the properties of direct resin-based composites: a meta-analysis review of in vitro studies

Abstract

Objectives: This study systematically revised the literature to answer the following question: do modeler liquids (MLs) affect the properties of direct resin-based composites (RBCs)?

Materials and methods: The review followed the PRISMA statement, and the search was conducted in PubMed, Scopus, Web of Science, Embase, and Lilacs databases. Studies were included if they investigated the properties of RBCs prepared using the restorative dental modeling insertion technique (RDMIT). The risk of bias was performed with the RoBDEMAT tool. Statistical analyses were conducted using Review Manager, and heterogeneity was assessed with the Cochran Q test and I² statistics.

Results: From 309 studies identified, 25 met the eligibility criteria, and 23 were meta-analyzed. In total, 27 MLs and 23 RBCs were evaluated. Modeled and non-modeled RBCs showed similar results in terms of cohesive strength, flexural strength, load-to-fracture, modulus of elasticity, work of fracture, degree of conversion, solubility, weight change, microhardness, and color change. Sorption and roughness benefited from the use of MLs, whereas translucency and whitening index were more adequate in the non-modeled RBCs. Aging affected similarly the modeled and non-modeled RBCs. Most studies showed a moderate risk of bias.

Conclusions: Modeled and non-modeled RBCs performed similarly in most of the properties, and the use of non-solvated lubricants offered beneficial effects in some cases.

Clinical relevance: When a balance has to be made between the RDMIT and the conventional technique, our review supports the safe application of modeler liquids for the handling of composite increments during the sculpting fabrication of direct resin-based restorations.

Keywords: Lubricating agents; Modeling resins; Restorative dental modeling insertion technique; Systematic review.