3D-printed resins intended for long-term restoration vs. conventionally used materials: A systematic review and network meta-analysis of in vitro studies

OBJECTIVES: This systematic review with network meta-analysis (NMA) evaluated whether three-dimensional (3D) printed resin-based composites (RBCs) intended for long-term dental restorations perform similarly or superiorly to conventional restorative materials. DATA SOURCES: The review followed the PRISMA extension for NMA. Six electronic databases were searched up to November 2025. STUDY SELECTION: In vitro studies assessing at least one commercially available 3D-printed RBC for long-term dental restorations and at least one conventional restorative material were eligible. Methodological quality was assessed using the RoBDEMAT tool, and data were synthesized using Bayesian NMA. RESULTS: From 2299 records, 50 studies met the inclusion criteria, of which 40 were included in the meta-analyses. Across mechanical, physical, reproducibility, and optical outcomes, 3D-printed RBCs generally performed similarly to or worse than most conventional materials. However, they demonstrated superior marginal and internal fit compared with glass ceramics, polymer-infiltrated ceramic networks, and polymeric restoratives, except when compared with direct RBCs, indicating enhanced dimensional accuracy. CONCLUSIONS: Although 3D printing achieved superior trueness and internal/marginal fit relative to most conventional restorative materials, the inferior mechanical performance, suboptimal microstructural characteristics, and limited optical stability of 3D-printed resins underscore the need for improvements in material formulation, post-curing strategies, and finishing and polishing protocols. CLINICAL SIGNIFICANCE: At present, 3D-printed resins for long-term single-unit restorations do not yet match the overall performance of established conventional restorative systems.