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4 pages, 177 KiB

Open AccessEditorial

Special Issue on “Biomaterials for Bone Tissue Engineering”

by José A. Sanz-Herrera

Appl. Sci. 2020, 10(8), 2660; https://doi.org/10.3390/app10082660 - 12 Apr 2020

Cited by 1 | Viewed by 1728

Abstract

The present Special Issue covers recent advances in the field of tissue engineering applied to bone tissue [...] Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

Research

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13 pages, 3809 KiB

Open AccessArticle

Automatic Method for Bone Segmentation in Cone Beam Computed Tomography Data Set

by Mantas Vaitiekūnas, Darius Jegelevičius, Andrius Sakalauskas and Simonas Grybauskas

Appl. Sci. 2020, 10(1), 236; https://doi.org/10.3390/app10010236 - 27 Dec 2019

Cited by 11 | Viewed by 4312

Abstract

Due to technical aspects of Cone Beam Computed Tomography (CBCT), the automatic methods for bone segmentation are not widely used in the clinical practice of endodontics, orthodontics, oral and maxillofacial surgery. The aim of this study was to evaluate method’s accuracy for bone [...] Read more.

Due to technical aspects of Cone Beam Computed Tomography (CBCT), the automatic methods for bone segmentation are not widely used in the clinical practice of endodontics, orthodontics, oral and maxillofacial surgery. The aim of this study was to evaluate method’s accuracy for bone segmentation in CBCT data sets. The sliding three dimensional (3D) window, histogram filter and Otsu’s method were used to implement the automatic segmentation. The results of automatic segmentation were compared with the results of segmentation performed by an experienced oral and maxillofacial surgeon. Twenty patients and their forty CBCT data sets were used in this study (20 preoperative and 20 postoperative). Intraclass Correlation Coefficients (ICC) were calculated to prove the reliability of surgeon segmentations. ICC was 0.958 with 95% confidence interval [0.896 ... 0.983] in preoperative data sets and 0.931 with 95% confidence interval [0.836 ... 0.972] in postoperative data sets. Three basic metrics were used in order to evaluate the accuracy of the automatic method—Dice Similarity Coefficient (DSC), Root Mean Square (RMS), Average Distance Error (ADE) of surfaces mismatch and additional metric in order to evaluate computation time of segmentation was used. The mean value of preoperative DSC was 0.921, postoperative—0.911, the mean value of preoperative RMS was 0.559 mm, postoperative—0.647 mm, the ADE value of preoperative cases was 0.043 mm, postoperative—0.057 mm, the mean computational time to perform the segmentation was 46 s. The automatic method showed clinically acceptable accuracy results and thus can be used as a new tool for automatic bone segmentation in CBCT data. It can be applied in oral and maxillofacial surgery for performance of 3D Virtual Surgical Plan (VSP) or for postoperative follow-up. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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17 pages, 5170 KiB

Open AccessArticle

Multiscale Characterisation of Cortical Bone Tissue

by José A. Sanz-Herrera, Juan Mora-Macías, Esther Reina-Romo, Jaime Domínguez and Manuel Doblaré

Appl. Sci. 2019, 9(23), 5228; https://doi.org/10.3390/app9235228 - 1 Dec 2019

Cited by 5 | Viewed by 2931

Abstract

Multiscale analysis has become an attractive technique to predict the behaviour of materials whose microstructure strongly changes spatially or among samples, with that microstructure controlling the local constitutive behaviour. This is the case, for example, of most biological tissues—such as bone. Multiscale approaches [...] Read more.

Multiscale analysis has become an attractive technique to predict the behaviour of materials whose microstructure strongly changes spatially or among samples, with that microstructure controlling the local constitutive behaviour. This is the case, for example, of most biological tissues—such as bone. Multiscale approaches not only allow, not only to better characterise the local behaviour, but also to predict the field-variable distributions (e.g., strains, stresses) at both scales (macro and micro) simultaneously. However, multiscale analysis usually lacks sufficient experimental feedback to demonstrate its validity. In this paper an experimental and numerical micromechanics analysis is developed with application to cortical bone. Displacement and strain fields are obtained across the microstructure by means of digital image correlation (DIC). The other mechanical variables are computed following the micromechanics theory. Special emphasis is given to the differences found in the different field variables between the micro- and macro-structures, which points out the need for this multiscale approach in cortical bone tissue. The obtained results are used to establish the basis of a multiscale methodology with application to the analysis of bone tissue mechanics at different spatial scales. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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15 pages, 4196 KiB

Open AccessArticle

Electrical Stimulation through Conductive Substrate to Enhance Osteo-Differentiation of Human Dental Pulp-Derived Stem Cells

by Yu-Che Cheng, Chien-Hsun Chen, Hong-Wei Kuo, Ting-Ling Yen, Ya-Yuan Mao and Wei-Wen Hu

Appl. Sci. 2019, 9(18), 3938; https://doi.org/10.3390/app9183938 - 19 Sep 2019

Cited by 17 | Viewed by 3830

Abstract

Human dental pulp-derived stem cells (hDPSCs) are promising cellular sources for bone healing. The acceleration of their differentiation should be beneficial to their clinical application. Therefore, a conductive polypyrrole (PPy)-made electrical stimulation (ES) device was fabricated to provide direct-current electric field (DCEF) treatment, [...] Read more.

Human dental pulp-derived stem cells (hDPSCs) are promising cellular sources for bone healing. The acceleration of their differentiation should be beneficial to their clinical application. Therefore, a conductive polypyrrole (PPy)-made electrical stimulation (ES) device was fabricated to provide direct-current electric field (DCEF) treatment, and its effect on osteo-differentiation of hDPSCs was investigated in this study. To determine the optimal treating time, electrical field of 0.33 V/cm was applied to hDPSCs once for 4 h on different days after the osteo-induction. The alizarin red S staining results suggested that ES accelerated the mineralization rates of hDPSCs. The quantification analysis results revealed a nearly threefold enhancement in calcium deposition by ES at day 0, 2, and 4, whereas the promotion effect in later stages was in vain. To determine the ES-mediated signaling pathway, the expression of genes in the bone morphogenetic protein (BMP) family and related receptors were quantified using qPCR. In the early stages of osteo-differentiation, the mRNA levels of BMP2, BMP3, BMP4, and BMP5 were increased significantly in the ES groups, indicating that these genes were involved in the specific signaling routes induced by ES. We are the first using DCEF to improve the osteo-differentiation of hDPSCs, and our results promise the therapeutic applications of hDPSCs on cell-based bone tissue engineering. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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11 pages, 5124 KiB

Open AccessArticle

Mechanical Behavior of Ti6Al4V Scaffolds Filled with CaSiO₃ for Implant Applications

by Ramin Rahmani, Maksim Antonov, Lauri Kollo, Yaroslav Holovenko and Konda Gokuldoss Prashanth

Appl. Sci. 2019, 9(18), 3844; https://doi.org/10.3390/app9183844 - 13 Sep 2019

Cited by 51 | Viewed by 6104

Abstract

Triply periodic minimal surfaces (TPMS) are becoming increasingly attractive due to their biomedical applications and ease of production using additive manufacturing techniques. In the present paper, the architecture of porous scaffolds was utilized to seek for the optimized cellular structure subjected to compression [...] Read more.

Triply periodic minimal surfaces (TPMS) are becoming increasingly attractive due to their biomedical applications and ease of production using additive manufacturing techniques. In the present paper, the architecture of porous scaffolds was utilized to seek for the optimized cellular structure subjected to compression loading. The deformation and stress distribution of five lightweight scaffolds, namely: Rectangular, primitive, lattice, gyroid and honeycomb Ti6Al4V structures were studied. Comparison of finite element simulations and experimental compressive test results was performed to illustrate the failure mechanism of these scaffolds. The experimental compressive results corroborate reasonably with the finite element analyses. Results of this study can be used for bone implants, biomaterial scaffolds and antibacterial applications, produced from the Ti6Al4V scaffold built by a selective laser melting (SLM) method. In addition, Ti6Al4V manufactured metallic lattice was filled by wollastonite (CaSiO₃) through spark plasma sintering (SPS) to illustrate the method for the production of a metallic-ceramic composite suitable for bone tissue engineering. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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18 pages, 8188 KiB

Open AccessArticle

A Comparative Study of Continuum and Structural Modelling Approaches to Simulate Bone Adaptation in the Pelvic Construct

by Dan T. Zaharie and Andrew T.M. Phillips

Appl. Sci. 2019, 9(16), 3320; https://doi.org/10.3390/app9163320 - 13 Aug 2019

Cited by 4 | Viewed by 4035

Abstract

This study presents the development of a number of finite element (FE) models of the pelvis using different continuum and structural modelling approaches. Four FE models were developed using different modelling approaches: continuum isotropic, continuum orthotropic, hybrid isotropic and hybrid orthotropic. The models [...] Read more.

This study presents the development of a number of finite element (FE) models of the pelvis using different continuum and structural modelling approaches. Four FE models were developed using different modelling approaches: continuum isotropic, continuum orthotropic, hybrid isotropic and hybrid orthotropic. The models were subjected to an iterative adaptation process based on the Mechanostat principle. Each model was adapted to a number of common daily living activities (walking, stair ascent, stair descent, sit-to-stand and stand-to-sit) by applying onto it joint and muscle loads derived using a musculoskeletal modelling framework. The resulting models, along with a structural model previously developed by the authors, were compared visually in terms of bone architecture, and their response to a single load case was compared to a continuum FE model derived from computed tomography (CT) imaging data. The main findings of this study were that the continuum orthotropic model was the closest to the CT derived model in terms of load response albeit having less total bone volume, suggesting that the role of material directionality in influencing the maximum orthotropic Young’s modulus should be included in continuum bone adaptation models. In addition, the hybrid models, where trabecular and cortical bone were distinguished, had similar outcomes, suggesting that the approach to modelling trabecular bone is less influential when the cortex is modelled separately. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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22 pages, 3420 KiB

Open AccessArticle

FEM-Based Compression Fracture Risk Assessment in Osteoporotic Lumbar Vertebra L1

by Algirdas Maknickas, Vidmantas Alekna, Oleg Ardatov, Olga Chabarova, Darius Zabulionis, Marija Tamulaitienė and Rimantas Kačianauskas

Appl. Sci. 2019, 9(15), 3013; https://doi.org/10.3390/app9153013 - 26 Jul 2019

Cited by 14 | Viewed by 3825

Abstract

This paper presents a finite element method (FEM)-based fracture risk assessment in patient-specific osteoporotic lumbar vertebra L1. The influence of osteoporosis is defined by variation of parameters such as thickness of the cortical shell, the bone volume–total volume ratio (BV/TV), and the trabecular [...] Read more.

This paper presents a finite element method (FEM)-based fracture risk assessment in patient-specific osteoporotic lumbar vertebra L1. The influence of osteoporosis is defined by variation of parameters such as thickness of the cortical shell, the bone volume–total volume ratio (BV/TV), and the trabecular bone score (TBS). The mechanical behaviour of bone is defined using the Ramberg–Osgood material model. This study involves the static and nonlinear dynamic calculations of von Mises stresses and follows statistical processing of the obtained results in order to develop the patient-specific vertebra reliability. In addition, different scenarios of parameters show that the reliability of the proposed model of human vertebra highly decreases with low levels of BV/TV and is critical due to the thinner cortical bone, suggesting high trauma risk by reason of osteoporosis. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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9 pages, 1166 KiB

Open AccessArticle

Potential Marker Genes for Predicting Adipogenic Differentiation of Mesenchymal Stromal Cells

by Masami Kanawa, Akira Igarashi, Katsumi Fujimoto, Veronica Sainik Ronald, Yukihito Higashi, Hidemi Kurihara, Yukio Kato and Takeshi Kawamoto

Appl. Sci. 2019, 9(14), 2942; https://doi.org/10.3390/app9142942 - 23 Jul 2019

Cited by 3 | Viewed by 4060

Abstract

Mesenchymal stromal cells (MSCs) are a promising source for tissue engineering of soft connective tissues. However, the differentiation capacity of MSCs varies among individual cell lines. Here, we show marker genes to predict the adipogenic potential of MSCs. To clarify the correlation between [...] Read more.

Mesenchymal stromal cells (MSCs) are a promising source for tissue engineering of soft connective tissues. However, the differentiation capacity of MSCs varies among individual cell lines. Here, we show marker genes to predict the adipogenic potential of MSCs. To clarify the correlation between gene expression patterns before adipogenic induction and the differentiation level of MSCs after differentiation, we compared mRNA levels of 95 genes and glycerol-3-phosphate dehydrogenase (GPDH) activities in 15 MSC lines (five jaw and 10 ilium MSCs) from 15 donors. Expression profiles of 22 genes before differentiation significantly correlated with GPDH activities after differentiation. Expression levels of 11 out of the 22 genes in highly potent ilium MSCs were at least three times higher compared with jaw MSCs, which have limited differentiation potential. Furthermore, three-dimensional scatter plot for mRNA expression of ITGA5, CDKN2D, and CD74 could completely distinguish highly potent MSCs from poorly potent MSCs for adipogenesis. The treatment of MSC cultures with the anti-ITGA5 antibody reduced adipogenic differentiation of MSCs. Collectively, these results suggest that the three genes play a role in adipogenesis before induction and can serve as predictors to select potent MSCs for adipogenic differentiation. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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12 pages, 8018 KiB

Open AccessArticle

Analysis of Damage Models for Cortical Bone

by Jacobo Baldonedo, José R. Fernández, José A. López-Campos and Abraham Segade

Appl. Sci. 2019, 9(13), 2710; https://doi.org/10.3390/app9132710 - 3 Jul 2019

Cited by 4 | Viewed by 2798

Abstract

Bone tissue is a material with a complex structure and mechanical properties. Diseases or even normal repetitive loads may cause microfractures to appear in the bone structure, leading to a deterioration of its properties. A better understanding of this phenomenon will lead to [...] Read more.

Bone tissue is a material with a complex structure and mechanical properties. Diseases or even normal repetitive loads may cause microfractures to appear in the bone structure, leading to a deterioration of its properties. A better understanding of this phenomenon will lead to better predictions of bone fracture or bone-implant performance. In this work, the model proposed by Frémond and Nedjar in 1996 (initially for concrete structures) is numerically analyzed and compared against a bone specific mechanical model proposed by García et al. in 2009. The objective is to evaluate both models implemented with a finite element method. This will allow us to determine if the modified Frémond–Nedjar model is adequate for this purpose. We show that, in one dimension, both models show similar results, reproducing the qualitative behaviour of bone subjected to typical engineering tests. In particular, the Frémond–Nedjar model with the introduced modifications shows good agreement with experimental data. Finally, some two-dimensional results are also provided for the Frémond–Nedjar model to show its behaviour in the simulation of a real tensile test. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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14 pages, 3300 KiB

Open AccessArticle

Scaffolds with a High Surface Area-to-Volume Ratio and Cultured Under Fast Flow Perfusion Result in Optimal O₂ Delivery to the Cells in Artificial Bone Tissues

by Thanh Danh Nguyen, Olufemi E. Kadri, Vassilios I. Sikavitsas and Roman S. Voronov

Appl. Sci. 2019, 9(11), 2381; https://doi.org/10.3390/app9112381 - 11 Jun 2019

Cited by 19 | Viewed by 6453

Abstract

Tissue engineering has the potential for repairing large bone defects, which impose a heavy financial burden on the public health. However, difficulties with O₂ delivery to the cells residing in the interior of tissue engineering scaffolds make it challenging to grow artificial [...] Read more.

Tissue engineering has the potential for repairing large bone defects, which impose a heavy financial burden on the public health. However, difficulties with O₂ delivery to the cells residing in the interior of tissue engineering scaffolds make it challenging to grow artificial tissues of clinically-relevant sizes. This study uses image-based simulation in order to provide insight into how to better optimize the scaffold manufacturing parameters, and the culturing conditions, in order to resolve the O₂ bottleneck. To do this, high resolution 3D X-ray images of two common scaffold types (salt leached foam and non-woven fiber mesh) are fed into Lattice Boltzmann Method fluid dynamics and reactive Lagrangian Scalar Tracking mass transfer solvers. The obtained findings indicate that the scaffolds should have maximal surface area-to-solid volume ratios for higher chances of the molecular collisions with the cells. Furthermore, the cell culture media should be flown through the scaffold pores as fast as practically possible (without detaching or killing the cells). Finally, we have provided a parametric sweep that maps how the molecular transport within the scaffolds is affected by variations in rates of O₂ consumption by the cells. Ultimately, the results of this study are expected to benefit the computer-assisted design of tissue engineering scaffolds and culturing experiments. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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18 pages, 3063 KiB

Open AccessArticle

Establishment of a Numerical Model to Design an Electro-Stimulating System for a Porcine Mandibular Critical Size Defect

by Hendrikje Raben, Peer W. Kämmerer, Rainer Bader and Ursula van Rienen

Appl. Sci. 2019, 9(10), 2160; https://doi.org/10.3390/app9102160 - 27 May 2019

Cited by 23 | Viewed by 4123

Abstract

Electrical stimulation is a promising therapeutic approach for the regeneration of large bone defects. Innovative electrically stimulating implants for critical size defects in the lower jaw are under development and need to be optimized in silico and tested in vivo prior to application. [...] Read more.

Electrical stimulation is a promising therapeutic approach for the regeneration of large bone defects. Innovative electrically stimulating implants for critical size defects in the lower jaw are under development and need to be optimized in silico and tested in vivo prior to application. In this context, numerical modelling and simulation are useful tools in the design process. In this study, a numerical model of an electrically stimulated minipig mandible was established to find optimal stimulation parameters that allow for a maximum area of beneficially stimulated tissue. Finite-element simulations were performed to determine the stimulation impact of the proposed implant design and to optimize the electric field distribution resulting from sinusoidal low-frequency (

f = 20 Hz

) electric stimulation. Optimal stimulation parameters of the electrode length

h_{el} = 25 m m

and the stimulation potential

φ_{stim} = 0.5 V

were determined. These parameter sets shall be applied in future in vivo validation studies. Furthermore, our results suggest that changing tissue properties during the course of the healing process might make a feedback-controlled stimulation system necessary. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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11 pages, 2920 KiB

Open AccessArticle

Biomechanical Evaluation of the Effect of Mesenchymal Stem Cells on Cartilage Regeneration in Knee Joint Osteoarthritis

by Yong-Gon Koh, Jin-Ah Lee, Hwa-Yong Lee, Hyo-Jeong Kim and Kyoung-Tak Kang

Appl. Sci. 2019, 9(9), 1868; https://doi.org/10.3390/app9091868 - 7 May 2019

Cited by 4 | Viewed by 3309

Abstract

Numerous clinical studies have reported cell-based treatments for cartilage regeneration in knee joint osteoarthritis using mesenchymal stem cells (MSCs). However, the post-surgery rehabilitation and weight-bearing times remain unclear. Phenomenological computational models of cartilage regeneration have been only partially successful in predicting experimental results [...] Read more.

Numerous clinical studies have reported cell-based treatments for cartilage regeneration in knee joint osteoarthritis using mesenchymal stem cells (MSCs). However, the post-surgery rehabilitation and weight-bearing times remain unclear. Phenomenological computational models of cartilage regeneration have been only partially successful in predicting experimental results and this may be due to simplistic modeling assumptions and loading conditions of cellular activity. In the present study, we developed a knee joint model of cell and tissue differentiation based on a more mechanistic approach, which was applied to cartilage regeneration in osteoarthritis. First, a phenomenological biphasic poroelastic finite element model was developed and validated according to a previous study. Second, this method was applied to a real knee joint model with a cartilage defect created to simulate the tissue regeneration process. The knee joint model was able to accurately predict several aspects of cartilage regeneration, such as the cell and tissue distributions in the cartilage defect. Additionally, our results indicated that gait cycle loading with flexion was helpful for cartilage regeneration compared to the use of simple weight-bearing loading. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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14 pages, 1474 KiB

Open AccessArticle

A Radiological Approach to Evaluate Bone Graft Integration in Reconstructive Surgeries

by Carlo F. Grottoli, Riccardo Ferracini, Mara Compagno, Alessandro Tombolesi, Osvaldo Rampado, Lucrezia Pilone, Alessandro Bistolfi, Alda Borrè, Alberto Cingolani and Giuseppe Perale

Appl. Sci. 2019, 9(7), 1469; https://doi.org/10.3390/app9071469 - 8 Apr 2019

Cited by 9 | Viewed by 3379

Abstract

(1) Background: Bone tissue engineering is a promising tool to develop new smart solutions for regeneration of complex bone districts, from orthopedic to oral and maxillo-facial fields. In this respect, a crucial characteristic for biomaterials is the ability to fully integrate within the [...] Read more.

(1) Background: Bone tissue engineering is a promising tool to develop new smart solutions for regeneration of complex bone districts, from orthopedic to oral and maxillo-facial fields. In this respect, a crucial characteristic for biomaterials is the ability to fully integrate within the patient body. In this work, we developed a novel radiological approach, in substitution to invasive histology, for evaluating the level of osteointegration and osteogenesis, in both qualitative and quantitative manners. (2) SmartBone®, a composite xeno-hybrid bone graft, was selected as the base material because of its remarkable effectiveness in clinical practice. Using pre- and post-surgery computed tomography (CT), we built 3D models that faithfully represented the patient’s anatomy, with special attention to the bone defects. (3) Results: This way, it was possible to assess whether the new bone formation respected the natural geometry of the healthy bone. In all cases of the study (four dental, one maxillo-facial, and one orthopedic) we evaluated the presence of new bone formation and volumetric increase. (4) Conclusion: The newly established radiological protocol allowed the tracking of SmartBone® effective integration and bone regeneration. Moreover, the patient’s anatomy was completely restored in the defect area and functionality completely rehabilitated without foreign body reaction or inflammation. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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13 pages, 1958 KiB

Open AccessFeature PaperArticle

Porous Titanium for Biomedical Applications: Evaluation of the Conventional Powder Metallurgy Frontier and Space-Holder Technique

by Sheila Lascano, Cristina Arévalo, Isabel Montealegre-Melendez, Sergio Muñoz, José A. Rodriguez-Ortiz, Paloma Trueba and Yadir Torres

Appl. Sci. 2019, 9(5), 982; https://doi.org/10.3390/app9050982 - 8 Mar 2019

Cited by 66 | Viewed by 5052

Abstract

Titanium and its alloys are reference materials in biomedical applications because of their desirable properties. However, one of the most important concerns in long-term prostheses is bone resorption as a result of the stress-shielding phenomena. Development of porous titanium for implants with a [...] Read more.

Titanium and its alloys are reference materials in biomedical applications because of their desirable properties. However, one of the most important concerns in long-term prostheses is bone resorption as a result of the stress-shielding phenomena. Development of porous titanium for implants with a low Young’s modulus has accomplished increasing scientific and technological attention. The aim of this study is to evaluate the viability, industrial implementation and potential technology transfer of different powder-metallurgy techniques to obtain porous titanium with stiffness values similar to that exhibited by cortical bone. Porous samples of commercial pure titanium grade-4 were obtained by following both conventional powder metallurgy (PM) and space-holder technique. The conventional PM frontier (Loose-Sintering) was evaluated. Additionally, the technical feasibility of two different space holders (NH₄HCO₃ and NaCl) was investigated. The microstructural and mechanical properties were assessed. Furthermore, the mechanical properties of titanium porous structures with porosities of 40% were studied by Finite Element Method (FEM) and compared with the experimental results. Some important findings are: (i) the optimal parameters for processing routes used to obtain low Young’s modulus values, retaining suitable mechanical strength; (ii) better mechanical response was obtained by using NH₄HCO₃ as space holder; and (iii) Ti matrix hardening when the interconnected porosity was 36–45% of total porosity. Finally, the advantages and limitations of the PM techniques employed, towards an industrial implementation, were discussed. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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8 pages, 851 KiB

Open AccessArticle

Influence of Implant Dimensions and Position on Implant Stability: A Prospective Clinical Study in Maxilla Using Resonance Frequency Analysis

by Antonio Nappo, Carlo Rengo, Giuseppe Pantaleo, Gianrico Spagnuolo and Marco Ferrari

Appl. Sci. 2019, 9(5), 860; https://doi.org/10.3390/app9050860 - 27 Feb 2019

Cited by 13 | Viewed by 3001

Abstract

Implant stability is relevant for the correct osseointegration and long-term success of dental implant treatments. The aim of this study has been to evaluate the influence of implant dimensions and position on primary and secondary stability of implants placed in maxilla using resonance [...] Read more.

Implant stability is relevant for the correct osseointegration and long-term success of dental implant treatments. The aim of this study has been to evaluate the influence of implant dimensions and position on primary and secondary stability of implants placed in maxilla using resonance frequency analysis. Thirty-one healthy patients who underwent dental implant placement were enrolled for the study. A total of 70 OsseoSpeed TX (Astra Tech Implant System—Dentsply Implants; Mölndal, Sweden) implants were placed. All implants have been placed according to a conventional two-stage surgical procedure according to the manufacturer instructions. Bone quality and implant stability quotient were recorded. Mean implant stability quotient (ISQ) at baseline (ISQ1) was statistically significant lower compared to 3-months post-implant placement (ISQ2) (p < 0.05). Initial implant stability was significantly higher with 4 mm diameter implants with respect to 3.5 mm. No differences were observed within maxilla regions. Implant length, diameter and maxillary regions have an influence on primary stability. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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9 pages, 2872 KiB

Open AccessArticle

Biomechanical Evaluation of a New Fixation Type in 3D-Printed Periacetabular Implants using a Finite Element Simulation

by Dae Woo Park, Aekyeong Lim, Jong Woong Park, Kwon Mook Lim and Hyun Guy Kang

Appl. Sci. 2019, 9(5), 820; https://doi.org/10.3390/app9050820 - 26 Feb 2019

Cited by 19 | Viewed by 5028

Abstract

Pelvic implants require complex geometrical shapes to reconstruct unusual areas of bone defects, as well as a high mechanical strength in order to endure high compressive loads. The electron beam melting (EBM) method is capable of directly fabricating complex metallic structures and shapes [...] Read more.

Pelvic implants require complex geometrical shapes to reconstruct unusual areas of bone defects, as well as a high mechanical strength in order to endure high compressive loads. The electron beam melting (EBM) method is capable of directly fabricating complex metallic structures and shapes based on digital models. Fixation design is important during the 3D printing of pelvic implants, given that the fixation secures the pelvic implants to the remaining bones, while also bearing large amounts of the loads placed on the bone. In this study, a horseshoe-shaped plate fixation with a bridge component between two straight plates is designed to enhance the mechanical stability of pelvic implants. The aim of this study is to investigate the biomechanics of the horseshoe-shaped plate fixation in a 3D-printed pelvic implant using a finite element (FE) simulation. First, computed tomography (CT) scans were acquired from a patient with periacetabular bone tumors. Second, 3D FE implant models were created using the patient’s Digital Imaging and Communications in Medicine (DICOM) data. Third, a FE simulation was conducted and the stress distribution between a conventional straight-type plate model, and the horseshoe-shaped plate model was compared. In both of the models, high-stress regions were observed at the iliac fixation area. In contrast, minimal stress regions were located at the pubic ramus and ischium fixation area. The key finding of this study was that the maximal stress of the horseshoe-shaped plate model (38.6 MPa) was 21% lower than that of the straight-type plate model (48.9 MPa) in the iliac fixation area. The clinical potential for the application of the horseshoe-shaped plate fixation model to the pelvic implant has been demonstrated, although this is a pilot study. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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Review

Jump to: Editorial, Research

17 pages, 1495 KiB

Open AccessFeature PaperReview

Continuum Modeling and Simulation in Bone Tissue Engineering

by Jose A. Sanz-Herrera and Esther Reina-Romo

Appl. Sci. 2019, 9(18), 3674; https://doi.org/10.3390/app9183674 - 5 Sep 2019

Cited by 8 | Viewed by 4812

Abstract

Bone tissue engineering is currently a mature methodology from a research perspective. Moreover, modeling and simulation of involved processes and phenomena in BTE have been proved in a number of papers to be an excellent assessment tool in the stages of design and [...] Read more.

Bone tissue engineering is currently a mature methodology from a research perspective. Moreover, modeling and simulation of involved processes and phenomena in BTE have been proved in a number of papers to be an excellent assessment tool in the stages of design and proof of concept through in-vivo or in-vitro experimentation. In this paper, a review of the most relevant contributions in modeling and simulation, in silico, in BTE applications is conducted. The most popular in silico simulations in BTE are classified into: (i) Mechanics modeling and scaffold design, (ii) transport and flow modeling, and (iii) modeling of physical phenomena. The paper is restricted to the review of the numerical implementation and simulation of continuum theories applied to different processes in BTE, such that molecular dynamics or discrete approaches are out of the scope of the paper. Two main conclusions are drawn at the end of the paper: First, the great potential and advantages that in silico simulation offers in BTE, and second, the need for interdisciplinary collaboration to further validate numerical models developed in BTE. Full article

(This article belongs to the Special Issue Biomaterials for Bone Tissue Engineering)

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