This study aims to produce by robocasting leucite/zirconia pieces with suitable mechanical and tribological performance, convenient aesthetics, and antibacterial properties to be used in dental crown replacement. Leucite pastes reinforced with 12.5%, 25%, and 37.5% wt. ZrO nanoparticles were prepared and used to print samples that after sintering were characterized in terms of density, shrinkage, morphology, porosity, mechanical and tribological properties and translucency. A coating of silver diamine fluoride (SDF) and potassium iodide (KI) was applied over the most promising material. The material’s antibacterial activity and cytotoxicity were assessed. It was found that the increase of ZrO reinforcement up to 25% enhanced both microhardness and fracture toughness of the sintered composite. However, for a superior content of ZrO, the increase of the porosity negatively affected the mechanical behaviour of the composite. Moreover, the composite with 25% ZrO exhibited neglectable wear in chewing simulator tests and induced the lowest wear on the antagonist dental cusps. Although this composite exhibited lower translucency than human teeth, it was three times higher than the ZrO glazed material. Coating this composite material with SDF+KI conferred antibacterial properties without inducing cytotoxicity. Robocasting of leucite reinforced with 25% ZrO led to best results. The obtained material revealed superior optical properties and tribomechanical behaviour compared to glazed ZrO (that is a common option in dental practice). Moreover, the application of SDF+KI coating impaired proliferation, which anticipates its potential benefit for preventing pathogenic bacterial complications associated with prosthetic crown placement.

中文翻译：

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经过优化的 3D 打印氧化锆增强白榴石，带有抗菌涂层，适用于牙科应用

本研究旨在通过机器人铸造生产具有合适的机械和摩擦学性能、方便的美观性和抗菌性能的白榴石/氧化锆件，用于牙冠置换。用 12.5%、25% 和 37.5% wt. 增强的白榴石浆料。制备 ZrO 纳米颗粒并用于打印样品，烧结后对样品进行密度、收缩、形态、孔隙率、机械和摩擦学性能以及半透明性的表征。在最有前途的材料上涂覆了氟化二胺银 (SDF) 和碘化钾 (KI) 涂层。评估了该材料的抗菌活性和细胞毒性。结果发现，ZrO 增强体增加高达 25%，可以提高烧结复合材料的显微硬度和断裂韧性。然而，对于较高含量的 ZrO，孔隙率的增加会对复合材料的机械性能产生负面影响。此外，含有 25% ZrO 的复合材料在咀嚼模拟器测试中表现出可忽略不计的磨损，并且对对抗牙尖的磨损最低。尽管这种复合材料的半透明度低于人类牙齿，但它比 ZrO 釉面材料高三倍。用 SDF+KI 涂覆这种复合材料可赋予抗菌性能，但不会引起细胞毒性。使用 25% ZrO 增强的白榴石进行自动铸造获得了最佳结果。与釉面 ZrO（牙科实践中的常见选择）相比，所获得的材料显示出优异的光学特性和摩擦力学行为。此外，SDF+KI涂层的应用会损害增殖，这预示着它对于预防与假体冠植入相关的致病细菌并发症的潜在益处。