Microstructure and mechanical properties of 3Y-TZP dental ceramics fabricated by selective laser sintering combined with cold isostatic pressing

Abstract

Additive manufacturing (AM) technology is showing great potential in dental restorations. In this paper, 3Y-TZP ceramics which are widely used in the fabrication of dental restorations were fabricated by selective laser sintering (SLS) combined with cold isostatic pressing (CIP) technology, and the effect of sintering temperature on phase composition, microstructure and mechanical properties of 3Y-TZP ceramics was investigated. 3Y-TZP/MgO/Epoxy resin E12 composite powder with good flowability and homogeneity was prepared by mechanical mixing method. The SLSed samples were obtained with optimum parameters (laser power = 7 W, scanning speed = 2600 mm/s, hatch spacing = 0.15 mm and layer thickness = 0.09 mm). Then they were densified by CIP (280 MPa, 5 min) process and sintered to obtain 3Y-TZP ceramics. It was found that the sample had the highest flexural strength of 279.50 ± 10.50 MPa and the maximum relative density of 86.65 ± 0.20% when sintered at 1500 °C due to the appropriate grain size and phase composition. Finally, some all-ceramic dental restorations were successfully fabricated by this technology. This work provides a new way for the manufacture of individualized all-ceramic dental restorations. Keywords: Selective laser sintering, 3Y-TZP dental ceramics, Cold isostatic pressing, Microstructure, Mechanical properties