Spheroidized powder enables the fabrication of highly translucent dental lithium disilicate glass-ceramics via 3D printing and controlled thermal processing.

Objectives

This study aimed to investigate the effects of heat treatment on the morphology of lithium disilicate glass-ceramic (LDGC) powder, as well as the influence of sintering conditions on the microstructure, mechanical properties, and translucency of LDGCs produced via 3D printing. Furthermore, the in vitro cytocompatibility of the specimens was assessed.

Methods

The optimal powder was selected from different spheroidized groups and used to prepare vat photopolymerizable slurry. The printed green bodies underwent a single-step debinding-sintering process, and specimens sintered at different temperatures were evaluated for mechanical and optical properties. The group exhibiting the best overall properties was further assessed for in vitro cytocompatibility.

Results

The spheroidized powder, characterized by a bimodal particle size distribution, exhibited excellent flowability at a solid loading of 50 vol%. Under optimal sintering conditions, the specimens attained a relative density of 99.6% and high translucency, with a light transmittance of 46.90 ± 0.51% at 550 nm, alongside a CIEDE2000 translucency parameter of 12.63 ± 0.26, comparable to IPS e.max CAD HT A2. The measured biaxial flexural strength, Vickers hardness, and fracture toughness were 274.98 ± 35.35 MPa, 642.31 ± 8.74 HV, and 2.72 ± 0.08 MPa·m¹ ᐟ², respectively. Moreover, the specimens exhibited favorable in vitro cytocompatibility. These findings support the clinical application potential of printed LDGCs.

Significance

A novel approach for fabricating highly translucent LDGC restorations via vat photopolymerization was developed, showing promise as a fabrication strategy for anterior aesthetic restorations.