Narrative review of 3D-printed temporary and permanent dental resin restorations
Andreas Keßler, Lukas Montenbruck, Falk Schwendicke, Jörg Lüchtenborg, Dalia Kaisarly
Abstract
The advent of 3D-printed permanent restorations marks a significant evolution in restorative dentistry, offering potential in terms of customization and production of complex geometries in a time- and cost-effective way by additive manufacturing. The aim was to critically review the literature on the current state of printing technologies, materials, as well as pre- and post-processing. It addresses the challenges and limitations associated with the adoption of printed permanent restoration materials. Vat polymerisations remain the dominant manufacturing process, while first attempts have been made in direct-ink-writing. The group of 3D-printable materials has shown great heterogeneity, significantly different mechanical and physical properties. Fillers enhanced the properties of resins and were added to materials for printable permanent restorations in contrast to those for temporary restorations. While the mechanical properties of 3D-printed resin restorations have significantly improved, the biggest challenges are color stability, water sorption, solubility, and anisotropy. Preprocessing and post-processing of the materials have been found to significantly impact material performance, while a systematic benchmarking of different approaches, needed to guide daily application, is missing. The biological properties and clinical performance, as well as the cost-effectiveness and applicability, remain almost unexplored. At present, 3D-printing of restorations is characterised by a high number of individual manual steps. A higher degree of automation is essential if it is to become a mainstream workflow.