scholarly journals Biomechanical Analyses of Porous Designs of 3D-Printed Titanium Implant for Mandibular Segmental Osteotomy Defects

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 576
Author(s):  
Yen-Wen Shen ◽  
Yuen-Shan Tsai ◽  
Jui-Ting Hsu ◽  
Ming-You Shie ◽  
Heng-Li Huang ◽  
...  
Keyword(s):  
Computational Models ◽  
Titanium Implant ◽  
Biomechanical Properties ◽  
In Vitro Experiments ◽  
Element Analysis ◽  
Group Function ◽  
Computed Tomography Images ◽  
Porous Implant ◽  
3D Printed

Clinically, a reconstruction plate can be used for the facial repair of patients with mandibular segmental defects, but it cannot restore their chewing function. The main purpose of this research is to design a new three-dimensionally (3D) printed porous titanium mandibular implant with both facial restoration and oral chewing function reconstruction. Its biomechanical properties were examined using both finite element analysis (FEA) and in vitro experiments. Cone beam computed tomography images of the mandible of a patient with oral cancer were selected as a reference to create 3D computational models of the bone and of the 3D-printed porous implant. The pores of the porous implant were circles or hexagons of 1 or 2 mm in size. A nonporous implant was fabricated as a control model. For the FEA, two chewing modes, namely right unilateral molar clench and right group function, were set as loading conditions. Regarding the boundary condition, the displacement of both condyles was fixed in all directions. For the in vitro experiments, an occlusal force (100 N) was applied to the abutment of the 3D-printed mandibular implants with and without porous designs as the loading condition. The porous mandibular implants withstood higher stress and strain than the nonporous mandibular implant, but all stress values were lower than the yield strength of Ti-6Al-4V (800 MPa). The strain value of the bone surrounding the mandibular implant was affected not only by the shape and size of the pores but also by the chewing mode. According to Frost’s mechanostat theory of bone, higher bone strain under the porous implants might help maintain or improve bone quality and bone strength. The findings of this study serve as a biomechanical reference for the design of 3D-printed titanium mandibular implants and require confirmation through clinical investigations.

scholarly journals 3D Printed Clamps for In Vitro Tensile Tests of Human Gracilis and the Superficial Third of Quadriceps Tendons

2021 ◽  
Vol 11 (6) ◽  
pp. 2563
Author(s):  
Ivan Grgić ◽  
Vjekoslav Wertheimer ◽  
Mirko Karakašić ◽  
Željko Ivandić
Keyword(s):  
3D Printing ◽  
Fused Deposition Modeling ◽  
Tensile Tests ◽  
Biomechanical Properties ◽  
Testing Procedure ◽  
Laboratory Equipment ◽  
Fused Deposition ◽  
Custom Made ◽  
3D Printed

Recent soft tissue studies have reported issues that occur during experimentation, such as the tissue slipping and rupturing during tensile loads, the lack of standard testing procedure and equipment, the necessity for existing laboratory equipment adaptation, etc. To overcome such issues and fulfil the need for the determination of the biomechanical properties of the human gracilis and the superficial third of the quadriceps tendons, 3D printed clamps with metric thread profile-based geometry were developed. The clamps’ geometry consists of a truncated pyramid pattern, which prevents the tendons from slipping and rupturing. The use of the thread application in the design of the clamp could be used in standard clamping development procedures, unlike in previously custom-made clamps. Fused deposition modeling (FDM) was used as a 3D printing technique, together with polylactic acid (PLA), which was used as a material for clamp printing. The design was confirmed and the experiments were conducted by using porcine and human tendons. The findings justify the usage of 3D printing technology for parts manufacturing in the case of tissue testing and establish independence from the existing machine clamp system, since it was possible to print clamps for each prepared specimen and thus reduce the time for experiment setup.

A CT-Based High-Order Finite Element Analysis of the Human Proximal Femur Compared to In-vitro Experiments

2006 ◽  
Vol 129 (3) ◽  
pp. 297-309 ◽  
Author(s):  
Zohar Yosibash ◽  
Royi Padan ◽  
Leo Joskowicz ◽  
Charles Milgrom
Keyword(s):  
Finite Element ◽  
Proximal Femur ◽  
Mechanical Response ◽  
Clinical Importance ◽  
High Order ◽  
Patient Specific ◽  
In Vitro Experiments ◽  
Element Analysis ◽  
Bone Response

The prediction of patient-specific proximal femur mechanical response to various load conditions is of major clinical importance in orthopaedics. This paper presents a novel, empirically validated high-order finite element method (FEM) for simulating the bone response to loads. A model of the bone geometry was constructed from a quantitative computerized tomography (QCT) scan using smooth surfaces for both the cortical and trabecular regions. Inhomogeneous isotropic elastic properties were assigned to the finite element model using distinct continuous spatial fields for each region. The Young’s modulus was represented as a continuous function computed by a least mean squares method. p-FEMs were used to bound the simulation numerical error and to quantify the modeling assumptions. We validated the FE results with in-vitro experiments on a fresh-frozen femur loaded by a quasi-static force of up to 1500N at four different angles. We measured the vertical displacement and strains at various locations and investigated the sensitivity of the simulation. Good agreement was found for the displacements, and a fair agreement found in the measured strain in some of the locations. The presented study is a first step toward a reliable p-FEM simulation of human femurs based on QCT data for clinical computer aided decision making.

scholarly journals A Comparison of Biomechanical Properties of Implant-Retained Overdenture Based on Precision Attachment Type

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2598
Author(s):  
Małgorzata Idzior-Haufa ◽  
Agnieszka A. Pilarska ◽  
Wiesław Hędzelek ◽  
Piotr Boniecki ◽  
Krzysztof Pilarski ◽  
...  
Keyword(s):  
Distal Part ◽  
Biomechanical Properties ◽  
Central Incisor ◽  
Element Analysis ◽  
Edentulous Mandible ◽  
The Matrix ◽  
Fea Analysis ◽  
Small Deformations ◽  
Made In

This paper aims to compare, in vitro, the biomechanical properties of an overdenture retained by two bar-retained implants and an overdenture retained by two bar-retained implants with ball attachments. An edentulous mandible model was prepared for the study based on the FRASACO mold with two implants. In the first system, the “rider” type (PRECI-HORIX, CEKA) retention structure and the complete mandibular denture with the matrix were made. In the second system, the “rider” type retention suprastructure was also used. In the distal part, (CEKA) clips were placed symmetrically, and a complete mandibular denture, together with the matrix on the bar, and the clip patrices were made. A numerical model was developed for each system where all elements were positioned and related to geometric relations, as in reality. The FEA analysis (finite element analysis) was carried out for seven types of loads: with vertical forces of 20, 50, and 100 N and oblique forces of 20 and 50 N acting on individual teeth of the denture, namely central incisor, canine, and first molar. Displacements, stresses, and deformations within the systems were investigated. Maximum denture displacement in the first system was 0.7 mm. Maximum bar stress amounted to 27.528 MPa, and implant stress to 23.16 MPa. Maximum denture displacement in the second system was 0.6 mm. Maximum bar stress amounted to 578.6 MPa, that of clips was 136.99 MPa, and that of implants was 51.418 MPa. Clips cause smaller displacement of the overdenture when it is loaded but generate higher stress within the precision elements and implants compared to a denture retained only by a bar. Regardless of the shape of the precision element, small deformations occur that mainly affect the mucosa and the matrix.

scholarly journals 3D-printed HA15-loaded β-Tricalcium Phosphate/Poly (Lactic-co-glycolic acid) Bone Tissue Scaffold Promotes Bone Regeneration in Rabbit Radial Defects

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Chuanchuan Zheng ◽  
Shokouh Attarilar ◽  
Kai Li ◽  
Chong Wang ◽  
Jia Liu ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Bone Tissue ◽  
Tricalcium Phosphate ◽  
Glycolic Acid ◽  
Bone Conduction ◽  
Biomechanical Properties ◽  
Bone Defects ◽  
Tissue Scaffold ◽  
3D Printed

In this study, a β-tricalcium phosphate (β-TCP)/poly (lactic-co-glycolic acid) (PLGA) bone tissue scaffold was loaded with osteogenesis-promoting drug HA15 and constructed by three-dimensional (3D) printing technology. This drug delivery system with favorable biomechanical properties, bone conduction function, and local release of osteogenic drugs could provide the basis for the treatment of bone defects. The biomechanical properties of the scaffold were investigated by compressive testing, showing comparable biomechanical properties with cancellous bone tissue. Furthermore, the microstructure, pore morphology, and condition were studied. Moreover, the drug release concentration, the effect of anti-tuberculosis drugs in vitro and in rabbit radial defects, and the ability of the scaffold to repair the defects were studied. The results show that the scaffold loaded with HA15 can promote cell differentiation into osteoblasts in vitro, targeting HSPA5. The micro-computed tomography scans showed that after 12 weeks of scaffold implantation, the defect of the rabbit radius was repaired and the peripheral blood vessels were regenerated. Thus, HA15 can target HSPA5 to inhibit endoplasmic reticulum stress which finally leads to promotion of osteogenesis, bone regeneration, and angiogenesis in the rabbit bone defect model. Overall, the 3D-printed β-TCP/PLGA-loaded HA15 bone tissue scaffold can be used as a substitute material for the treatment of bone defects because of its unique biomechanical properties and bone conductivity.

Research on Biomechanical Compatibility for the Artificial Anal Sphincter Based on Improved Actuator

2021 ◽  
Vol 15 (3) ◽  
Author(s):  
Peng Zan ◽  
Qiao Ding ◽  
Banghua Yang ◽  
Guofu Zhang ◽  
Yingjie Xue ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Anal Sphincter ◽  
In Vitro Experiments ◽  
Artificial Anal Sphincter ◽  
Element Analysis ◽  
Biomechanical Compatibility ◽  
Bowel Movements ◽  
Defecation Disorders ◽  
And Control

Abstract Anal incontinence, also known as fecal incontinence, refers to the loss of the body's ability to accumulate and control the liquid, solid, and gas contents in the rectum, increasing the frequency of bowel movements. It is a symptom of defecation disorders. The artificial anal sphincter provides a new solution for clinical treatment. In this paper, in order to solve the problem of biomechanical compatibility of the actuator of the artificial anal sphincter system, the original actuator was improved. The model of the rectum and the actuator was constructed by ANSYS. The mechanical finite element analysis of the clamping mechanism was carried out by simulating sphincter behavior, and the displacement cloud diagram and stress cloud diagram of the clamping rectum were obtained. in vitro experiments were carried out using pig intestine to simulate the rectum, which verified the effectiveness of the actuator. The results of the experiment show that the successful rate of holding the rectum reached 96% under the condition of ensuring the normal blood supply to the rectum. It fully proves that the actuator has good biomechanical compatibility.

Fabrication and finite element analysis of stereolithographic 3D printed microneedles for transdermal delivery of model dyes across human skin in vitro

2019 ◽  
Vol 137 ◽  
pp. 104976 ◽  
Author(s):  
Iakovos Xenikakis ◽  
Manolis Tzimtzimis ◽  
Konstantinos Tsongas ◽  
Dimitrios Andreadis ◽  
Euterpi Demiri ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Human Skin ◽  
Transdermal Delivery ◽  
Element Analysis ◽  
3D Printed
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