Shenzhen Upcera Dental Co., Ltd.

Dental caries in primary teeth is a significant global health problem. Conventional stainless-steel crowns (SSCs), widely used in pediatric dentistry, lack inherent antimicrobial properties. This study investigates a novel Cu-bearing titanium alloy, Ti6Al4V6Cu, fabricated by laser powder-bed fusion (LPBF), which is anticipated to offer both mechanical robustness and antibacterial performance.

This study aimed to comprehensively evaluate the suitability of 3D-printed Ti6Al4V6Cu alloy for pediatric crown applications by assessing its mechanical properties, corrosion resistance, biocompatibility, and antibacterial efficacy.

The alloy's mechanical and corrosion properties were analyzed via microhardness, universal testing, and electrochemical tests. Biocompatibility was evaluated using human gingival fibroblasts (HGFs) through CCK-8, IF, FCM, phalloidin, SEM, and qRT-PCR assays. Antibacterial activity againstStreptococcus mutanswas assessed using growth curves, plate counts, live/dead staining, lactic-acid production, TEM, and qRT-PCR. Crown internal fit was compared with traditional SSCs using silica-gel weighing and 3Shape software.

Ti6Al4V6Cu exhibited significantly higher surface hardness and compressive strength than pure Ti6Al4V and 304 stainless steel (P < 0.05), alongside superior corrosion resistance. The material demonstrated excellent biocompatibility with no cytotoxicity and supported normal HGF adhesion and proliferation. Antibacterial assays showed significant reductions in bacterial growth, biofilm formation, and acid production. TEM revealed structural damage to bacterial cells and elevated ROS levels, while qRT-PCR indicated downregulation of key virulence genes. The internal adaptation of TC4-6Cu crowns was significantly better than that of prefabricated SSCs (P < 0.05).

The 3D-printed TC4-6Cu alloy exhibits superior mechanical properties, enhanced corrosion resistance, excellent biocompatibility, and potent antibacterial effects, demonstrating strong potential as a next-generation material for pediatric dental crowns.

Repairing bone defects in the craniomaxillofacial region remains a significant challenge in oral and maxillofacial surgery. Polyether ether ketone (PEEK) is an emerging customizable bone replacement material for clinical treatment; however, the clinical application of three-dimensional (3D)-printed PEEK is limited by its poor cell adhesion ability and bioinertness. In this study, the cell adhesion ability and osteogenic properties of 3D-printed PEEK were improved by modifying its surface properties. First, methacrylated gelatin (GelMA) hydrogel containing β-tricalcium phosphate (β-TCP) was prepared and the appropriate β-TCP concentration was determined. Subsequently, sulfonation treatment was used to modify the surface of 3D-printed PEEK, which allowed the stable attachment of the GelMA hydrogel. Thus, 3D-printed bioactive PEEK was prepared successfully. In vitro and in vivo experiments showed that the 3D-printed bioactive PEEK increased the adhesion to bone marrow mesenchymal stem cells and osteogenic induction, which improved the cell adhesion and bone repair ability compared to unmodified 3D-printed PEEK. In summary, this study achieved bioactive modification of 3D-printed PEEK through a facile surface modification technique, which provides a new approach for future material design in the field of tissue engineering and regenerative medicine.

Titanium (Ti) alloys are widely used in bone repair due to their excellent biocompatibility and mechanical properties. However, managing post-implantation inflammatory responses in the defect region and accelerating the healing process remain major challenges in the design of such materials. As a bridge between the innate and adaptive immune systems, macrophages play a pivotal role in bone defect healing through their M2 polarization, which facilitates the secretion of tissue repair-promoting cytokines. Research on the role of copper ions (Cu²⁺) in regulating inflammatory responses at injury sites suggests their potential as active ions for incorporation into alloys as a secondary phase to modulate macrophage polarization. However, the effective concentration and mechanisms in this process remain unclear. Here, we synthesized Ti-xCu (x = 3, 5, 7 wt%) alloys and investigated the effects of copper concentration on macrophage M1/M2 polarization and the underlying mechanisms. In an 8-week rat mandibular bone regeneration experiment, Ti-5Cu demonstrated superior performance compared to pure titanium. At the early stage (2 weeks), Ti-5Cu promoted the dominance of M1 macrophages and upregulated inflammatory cytokines, facilitating the initial inflammatory response. Subsequently, a timely M1-to-M2 phenotype transition was observed, accompanied by elevated expression of the repair-related cytokine IL-10, ultimately leading to improved bone healing. This study provides a theoretical foundation for the development of titanium-copper composite materials with anti-inflammatory and pro-healing properties, paving the way for innovative solutions to promote bone defect repair.