ABSTRACT
Objective To make finite element analysis and compressive performance test on three-dimensional (3D) printed personalized poly-ether-ether-ketone (PEEK) condyle prosthesis, so as to analyze stress distribution characteristics and mechanical properties of the prosthesis, and to evaluate its clinical value and prospect. Methods The finite element models of PEEK condyle prosthesis, mandible and fixation screw were established by software such as CBCT, Mimics, Geomagic Studio, SolidWorks and ANSYS Workbench. The maximum mastication force was applied, and the maximum stress of the condyle prosthesis and screw, as well as the stress and strain of the mandible were recorded. In order to simulate the actual clinical situation, a special fixture was designed to test compression performance of the condyle prosthesis prepared by the fused deposition modeling (FDM) and selective laser sintering (SLS) at the rate of 1 mm/min. Results The peak stress of the PEEK condyle prosthesis was 10.733 MPa, which was located at the back of the condyle neck. The peak stress of 5 fixing screws was 9.707 5 MPa, which appeared on the 2# and 5# screws near the trailing edge of the mandibular ascending branch. The peak stress of both the prosthesis and the screw was smaller than its yield strength. The maximum pressure of the condyle prosthesis prepared by FDM and SLS was (3 814.7±442.6) N and (1 193.970±260.350) N, respectively. Compared with the SLS preparation, the FDM prepared prosthesis not only had higher compression strength but also better toughness. Conclusions The 3D printed personalized PEEK condyle prosthesis shows uniform stress distributions and good mechanical properties, which can provide the theoretical basis for PEEK as reconstruction material for repairing temporomandibular joint.
ABSTRACT
Objective To study the mechanical properties and biological characteristics of 3D-printed porous β-tricalcium phosphate ［β-Ca3(PO4)2, β-TCP］ scaffolds, so as to provide guidance for the design of composite scaffolds in animal experimentation. Methods Poly 1,8-octanediol citrate (POC), a kind of novel biodegradable materials, was used as the adhesive. The 3D-printed porous β-TCP scaffolds were fabricated by fused deposition modeling (FDM) technology, and Gly-Arg-Gly-Asp-Ser (GRGDS), a kind of polypeptides, was added into the scaffolds to improve the adhesive property of cells. The optical microscope and scanning electron microscope (SEM) were used to observe the micro-pore architectures of those scaffolds. The material testing machine was used to conduct compressive test on the scaffolds, and the water contact angles of the scaffolds were measured. The cell adhesion rate and proliferation rate of the scaffolds were also tested by in vitro cell experiment. The model of SD rat skull defects was repaired by the scaffolds, and the osteogenic ability in vivo was further studied. Results The GRGDS, remaining active, was evenly distributed in the composite scaffolds. The micro-pore architectures of the polypeptide modified scaffolds changed, with improvement in cell adhesion rate, while the compressive modulus, water contact angle and osteogenic ability in vivo of the scaffolds were not obviously affected. Conclusions The cell adhesion capacity of β-TCP composite scaffolds modified by polypeptide improved significantly, while the mechanical properties and hydrophilicity, osteogenic ability in vivo of the scaffolds were not affected very much. These research results provide new ideas for reconstruction of scaffolds for repairing bone defects in clinic, and a laboratory basis for further clinical application of this scaffold.