Properties and Behavior of Additively Manufactured Provisional Fixed Dental Prostheses: A Systematic Review on 3D Printing Orientations Relative to Applied Materials and Postprocessing.

Abstract

Objectives: This systematic review aimed to assess the influence of printing orientations alone and with other parameters, such as applied material and postprocessing, on the physical-mechanical properties and mechanical behavior of provisional fixed dental prostheses (FDPs).

Materials and methods: A comprehensive search of websites such as PubMed, Scopus, Web of Science, and Cochrane was conducted in July 2024. Adhering to PRISMA 2020 guidelines, the studies that investigated the impact of printing orientations on the physical and mechanical properties were included in this review. The modified CONSORT statement was utilized for the risk of bias assessment. A total of 24 records were included; the main build-up angles were horizontal, oblique, and vertical (0°, 45°, and 90°), and other angles such as 30° and 150° were also reported. The data focused on the impact of orientation on 3D-printed products from different materials, applying various postcuring times and artificial aging. Horizontally printed specimens exhibited significantly superior mechanical properties and behavior compared with other angles, while vertically printed specimens displayed the lowest results. Additionally, the material type, amount, and type of fillers and postcuring had the most substantial impacts; zirconia fillers showed more enhanced strength compared to silica fillers, and the mechanical behavior was enhanced with postcuring time of up to 120 min. Optical properties were more related to the materials and technology applied than to printing directions. Polishing of the products enhances surface quality and removes differences from various orientations. Resin specimens exhibited a high susceptibility to staining, irrespective of printing orientation. Furthermore, aging significantly influenced the mechanical properties, gloss, and surface quality of the specimens.

Conclusions: To achieve high-quality provisional FDPs, it is essential to select a horizontal orientation. Careful selection of materials is necessary, as well as adherence to optimal printing parameters. 3D-printed resin may not yet be suitable for permanent rehabilitation; however, it is appropriate for short- and long-term temporization.

Clinical significance: The production of dental parts is shifting to additive manufacturing; it is crucial to understand the impact of various parameters on the physical and mechanical behavior of dental parts, particularly provisional restorations, to ensure their durable clinical service.