Preparation of Porous Titanium Dental Implant by 3D Printing/Composite Coating and Its Biomechanical Properties and Flexural Strength

Abstract

Dental implants have been widely used in clinical practice. The 3D modeling software was used to design threedimensional (3D) models (in the shapes of long strips, discs, and screws), i.e., the Ti2.6Al1.2 V0.42 specimens. Meanwhile, the implant material was electrochemically precipitated, and a layer of chitosan nano-coating was added to the surface. To test the bone-binding ability and planting success rate of the material, the mechanical properties of the specimens with different porosity (0%∼70%) were firstly analyzed by the three-point bending method. Then, the screw-shaped titanium alloy specimens were divided into the solid group, the solid coating group, the solid 30% group, the coating 30% group, the solid 50% group, and the coating 50% group. The MC3T3-E1 cells were cultured, and the in vitro biological properties of the specimens were tested from different angles. The biomechanical properties and flexural strength of screw-shaped titanium alloy specimens in different groups were tested by using a universal testing machine. In the experiment, the prepared dental implants had the complete surface, uniform pore distribution, dense coating distribution, and less overall cracks. The elastic gradient of porous titanium specimens would decrease due to the increase of porosity. The cell activity of the test specimen was higher, and the percentage of viable cells exceeded 80%. The MTT test confirmed that the pores of the test specimen could promote the increase of MTT value (P < 0.05), and the test specimen/composite coating had higher ALP levels compared with the test pieces with no surface treatments (P < 0.05). In biomechanical properties and flexural strength tests, the increase of pores increased the biomechanical properties (P < 0.05) and decreased the flexural resistance (P < 0.05), while the increase of coating decreased the biomechanical properties and increased the flexural resistance (P < 0.05). The porous titanium alloy specimens were successfully prepared, and the chitosan-based composite coating was applied. The material was non-toxic, which was beneficial to cell proliferation and had good mechanical properties, thereby contributing to the growth of new bone.