Evaluation of mechanical properties of temporary restoration materials produced using different 3D printer technologies

Purpose: The purpose of this in-vitro study was to compare the mechanical properties of interim restorations produced using SLA, DLP, and LCD technologies with the specimens produced by milling and conventionally manufactured polymethyl methacrylate (PMMA). Material and methods: Stereolithography (SLA), digital light processing (DLP), and liquid crystal display (LCD) 3D printers were used as experimental groups, and milling (ML) and conventional (C) method was used as the control. Six different 3D printers (DWS Systems, Formlabs, Asiga, Mega, Vega, and Photon) were included. According to ISO 10477: 2004, 120 rectangular prism interim resin specimens with dimensions of 25×2×2 mm were prepared. The geometry of the specimens was designed with the CAD software program (Materialise 3-matic; Materialise). The production direction was set horizontally and the layer thickness was 50 µm (n=15). The produced samples were subjected to 3-point bending and microhardness tests. Weibull analysis was performed. Fracture surface analysis was performed using a SEM (Quanta 650 field emission SEM; FEI). Statistical data analysis was performed with 1-way ANOVA followed by the post hoc Dunnet T3 test (α=.05). Results: DWS (p=.696), FL (p=1.000), AS (p=1.000), VG (p=.375), and C (p=.494) groups showed elastic modulus values comparable to ML. FL and ML showed statistically similar flexural strength (p=1.000). All 3D printers except PH showed a statistically significantly higher microhardness value than C. PH showed statistically significantly lower mechanical properties than all groups. Conclusions: The specimens produced on the 3D printers included in the study showed different mechanical properties. Constitute a good alternative to the conventional method. Keywords: 3D Printer, Additive Manufacturing, Interim Restoration, Mechanical Properties