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1.
ACS Biomater Sci Eng ; 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-39227180

RESUMEN

With the accelerating trend of global aging, bone damage caused by orthopedic diseases, such as osteoporosis and fractures, has become a shared international event. Traffic accidents, high-altitude falls, and other incidents are increasing daily, and the demand for bone implant treatment is also growing. Although extensive research has been conducted in the past decade to develop medical implants for bone regeneration and healing of body tissues, due to their low biocompatibility, weak bone integration ability, and high postoperative infection rates, pure titanium alloys, such as Ti-6A1-4V and Ti-6A1-7Nb, although widely used in clinical practice, have poor induction of phosphate deposition and wear resistance, and Ti-Zr alloy exhibits a lack of mechanical stability and processing complexity. In contrast, the Ti-Ni alloy exhibits toxicity and low thermal conductivity. Nonthermal plasma (NTP) has aroused widespread interest in synthesizing and modifying implanted materials. More and more researchers are using plasma to modify target catalysts such as changing the dispersion of active sites, adjusting electronic properties, enhancing metal carrier interactions, and changing their morphology. NTP provides an alternative option for catalysts in the modification processes of oxidation, reduction, etching, coating, and doping, especially for materials that cannot tolerate thermodynamic or thermosensitive reactions. This review will focus on applying NTP technology in bone implant material modification and analyze the overall performance of three common types of bone implant materials, including metals, ceramics, and polymers. The challenges faced by NTP material modification are also discussed.

2.
Materials (Basel) ; 17(9)2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38730967

RESUMEN

Stress distribution and its magnitude during loading heavily influence the osseointegration of dental implants. Currently, no high-resolution, three-dimensional method of directly measuring these biomechanical processes in the peri-implant bone is available. The aim of this study was to measure the influence of different implant materials on stress distribution in the peri-implant bone. Using the three-dimensional ARAMIS camera system, surface strain in the peri-implant bone area was compared under simulated masticatory forces of 300 N in axial and non-axial directions for titanium implants and zirconia implants. The investigated titanium implants led to a more homogeneous stress distribution than the investigated zirconia implants. Non-axial forces led to greater surface strain on the peri-implant bone than axial forces. Thus, the implant material, implant system, and direction of force could have a significant influence on biomechanical processes and osseointegration within the peri-implant bone.

3.
Front Bioeng Biotechnol ; 12: 1335159, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38468690

RESUMEN

Purpose: The aim of this study is to develop a test bench, which integrates different complexity levels and enables in that way a flexible and dynamic testing for mid and long term intervals as well as testing of maximum loads till implant failure of different osteosynthesis systems on the mandible. Material and Methods: For this purpose, an analysis of the state of the art regarding existing test benches was combined with interviews of clinical experts to acquire a list of requirements. Based on these requirements a design for a modular test bench was developed. During the implementation of the test stand, functional tests were continuously carried out and improvements made. Depending on the level of complexity, the test bench can be used either as an incorporated variant or as a standalone solution. In order to verify the performance and the degree of fulfilment of the requirements of these two variants of the test bench, preliminary studies were carried out for all levels of complexity. In these preliminary studies, commercially available osteosynthesis and reconstruction plates were investigated for their biomechanical behaviour and compared with data from the literature. Results: In total, fourteen test runs were performed for the different levels of complexity. Firstly, five test runs were executed to test the simplified load scenario in the incorporated variant of the test bench. High forces could be transmitted without failure of the miniplates. Secondly a quasi-static test scenario was examined using the incorporated variant with simplified load insertion. Five experiments with a number of cycles between 40,896 and 100,000 cycles were carried out. In one case the quasi-static testing resulted in a fracture of the tested reconstruction plate with a failure mode similar to the clinical observations of failure. The last four test runs were carried out using the standalone variant of the test bench simulating complex load patterns via the insertion of forces through imitated muscles. During the test runs joint forces were measured and the amplitude and vector of the resulting joint forces were calculated for both temporomandibular joints. Differences in the force transmission depending on the implant system in comparison to the zero sample could be observed. Conclusion: The presented modular test bench showed to be applicable for examination of the biomechanical behavior of the mandible. It is characterized by the adjustability of the complexity regarding the load patterns and enables the subsequent integration of further sensor technologies. Follow-up studies are necessary to further qualify and optimize the test bench.

4.
J Mech Behav Biomed Mater ; 152: 106436, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38325168

RESUMEN

Due to the unique lamellar structures, physicochemical and biological properties, electronegative two-dimensional (2D) materials have been explored for surface modification of carbon fibers reinforced polyetheretherketone (CFR-PEEK) composite. Deposition of electronegative 2D materials based on a porous surface created by concentrated H2SO4 has been studied to promote osteogenesis of CFR-PEEK. Generally, a porous layer will be pre-built on CFR-PEEK through severe corrosion of concentrated sulfuric acid to help the loading of 2D materials. However, the severe corrosion will greatly reduce surface mechanical strength, especially wear resistance and hardness, which increases the risk of collapse or even peeling of the bioactive coating by external force. Herein, instead of the severe corrosion, a mild corrosion by concentrated HNO3 was applied to modify the surface of CFR-PEEK to pre-create a dense transition layer for the further surface decoration of electronegative 2D materials (graphene oxide (GO) and black phosphorus (BP), representatively). The results indicated that hardness and wear resistance of the dense transition layer were markedly higher than those of the porous layer. Although GO and BP can be both loaded on these two transition layers, -SO3H on the porous transition layer showed moderate cytotoxicity, while -NO2 on the dense transition layer showed good cytocompatibility. The dense transition layer displayed higher mineralized deposition in vitro and new bone formation rate in vivo than the porous transition layer, moreover, GO and BP coatings improved osteogenesis. This work offers inspirations for the construction of electronegative 2D material coating on CFR-PEEK based on chemical transition layers.


Asunto(s)
Benzofenonas , Grafito , Osteogénesis , Polímeros , Prótesis e Implantes , Fibra de Carbono , Cetonas , Fósforo , Polietilenglicoles
5.
Spine J ; 24(4): 721-729, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37875243

RESUMEN

BACKGROUND CONTEXT: Methods to improve osseointegration of orthopedic spinal implants remains a clinical challenge. Materials composed of poly-ether-ether-ketone (PEEK) and titanium are commonly used in orthopedic applications due to their inherent properties of biocompatibility. Titanium has a clinical reputation for durability and osseous affinity, and PEEK offers advantages of a modulus that approximates osseous structures and is radiolucent. The hypothesis for the current investigation was that a titanium plasma spray (TPS) coating may increase the rate and magnitude of circumferential and appositional trabecular osseointegration of PEEK and titanium implants versus uncoated controls. PURPOSE: Using an in vivo ovine model, the current investigation compared titanium plasma-sprayed PEEK and titanium dowels versus nonplasma-sprayed dowels. Using a time course study of 6 and 12 weeks postoperatively, experimental assays to quantify osseointegration included micro-computed tomography (microCT), biomechanical testing, and histomorphometry. STUDY DESIGN/SETTING: In-vivo ovine model. METHODS: Twelve skeletally mature crossbred sheep were equally randomized into postoperative periods of 6 and 12 weeks. Four types of dowel implants-PEEK, titanium plasma-sprayed PEEK (TPS PEEK), titanium, and titanium plasma-sprayed titanium (TPS titanium) were implanted into cylindrical metaphyseal defects in the distal femurs and proximal humeri (one defect per limb, n=48 sites). Sixteen nonoperative specimens (eight femurs and eight humeri) served as zero time-point controls. Half of the specimens underwent destructive biomechanical pullout testing and the remaining half quantitative microCT to quantify circumferential bone volume within 1 mm and 2 mm of the implant surface and histomorphometry to compute direct trabecular apposition. RESULTS: There were no intra- or perioperative complications. The TPS-coated implants demonstrated significantly higher peak loads at dowel pullout at 6 and 12 weeks compared with uncoated controls (p<.05). No differences were observed across dowel treatments at the zero time-point (p>.05). MicroCT results exhibited no significant differences in circumferential osseointegration between implants within 1 mm or 2 mm of the dowel surface (p>.05). Direct appositional osseointegration of trabecular bone based on histomorphometry was higher for TPS-coated groups, regardless of base material, compared with uncoated treatments at both time intervals (p<.05). CONCLUSIONS: The current in vivo study demonstrated the biological and mechanical advantages of plasma spray coatings. TPS improved histological incorporation and peak force required for implant extraction. CLINICAL SIGNIFICANCE: Plasma spray coatings may offer clinical benefit by improving biological fixation and osseointegration within the first 6 to 12 weeks postoperatively- the critical healing period for implant-based arthrodesis procedures.


Asunto(s)
Benzofenonas , Cetonas , Oseointegración , Polímeros , Animales , Ovinos , Cetonas/química , Titanio/química , Éter , Microtomografía por Rayos X , Éteres de Etila , Éteres , Materiales Biocompatibles Revestidos/química
6.
J Mech Behav Biomed Mater ; 148: 106222, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37948919

RESUMEN

In this work, 1 wt% of graphite oxide (GO) was used to strengthen the interface of carbon fibers (CF) reinforced polyetheretherketone (CFR-PEEK) composites, so as to obtain sufficiently high mechanical properties and bioactive surfaces which are two fundamental requirements for orthopedic/dental implants. Concretely, aminated GO was grafted onto oxidized CF in aqueous solution in a mild and non-toxic manner, subsequently, the CF grafted by GO was used for injection molding to prepare CFR-PEEK implant. The dispersibility of CF in the composites were remarkably boosted. Mechanical tests indicated that the flexural strength, compressive strength and hardness of CFR-PEEK were increased by 51%, 46%, and 30%, respectively. Furthermore, the flexural modulus increased to 11.67 ± 0.20 GPa and the compression modulus increased to 6.12 ± 0.11 GPa, which both meet the elastic modulus of human bone (6-30 GPa). The wear resistance was slightly improved. In the in vitro cell evaluation, CFR-PEEK with interface strengthening by GO showed no cytotoxicity and exhibited significantly enhanced adhesion and proliferation of Bone marrow mesenchymal stem cells (BMSCs) on the surface. More importantly, osteogenesis-related protein expression in vitro and osteogenetic evaluation in vivo all disclosed greatly accelerated osteo-differentiation of BMSCs on the composites due to the additive effect of GO at the interface. Based on this scheme, the CFR-PEEK composites with the dual functions of mechanical enhancement and osteointegration promotion holds great potential as implants in orthopedic/dental applications.


Asunto(s)
Grafito , Humanos , Osteogénesis , Polímeros , Polietilenglicoles/farmacología , Cetonas , Fibra de Carbono
7.
Mater Today Bio ; 22: 100784, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37731959

RESUMEN

Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices.

8.
Nanomaterials (Basel) ; 13(16)2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37630871

RESUMEN

Bioactive glasses (BGs) are especially useful materials in soft and bone tissue engineering and even in dentistry. They can be the solution to many medical problems, and they have a huge role in the healing processes of bone fractures. Interestingly, they can also promote skin regeneration and wound healing. Bioactive glasses are able to attach to the bone tissues and form an apatite layer which further initiates the biomineralization process. The formed intermediate apatite layer makes a connection between the hard tissue and the bioactive glass material which results in faster healing without any complications or side effects. This review paper summarizes the most recent advancement in the preparation of diverse types of BGs, such as silicate-, borate- and phosphate-based bioactive glasses. We discuss their physical, chemical, and mechanical properties detailing how they affect their biological performances. In order to get a deeper insight into the state-of-the-art in this area, we also consider their medical applications, such as bone regeneration, wound care, and dental/bone implant coatings.

9.
Bioact Mater ; 28: 155-166, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37250865

RESUMEN

The microstructural architecture of remodeled bone in the peri-implant region of screw implants plays a vital role in the distribution of strain energy and implant stability. We present a study in which screw implants made from titanium, polyetheretherketone and biodegradable magnesium-gadolinium alloys were implanted into rat tibia and subjected to a push-out test four, eight and twelve weeks after implantation. Screws were 4 mm in length and with an M2 thread. The loading experiment was accompanied by simultaneous three-dimensional imaging using synchrotron-radiation microcomputed tomography at 5 µm resolution. Bone deformation and strains were tracked by applying optical flow-based digital volume correlation to the recorded image sequences. Implant stabilities measured for screws of biodegradable alloys were comparable to pins whereas non-degradable biomaterials experienced additional mechanical stabilization. Peri-implant bone morphology and strain transfer from the loaded implant site depended heavily on the biomaterial utilized. Titanium implants stimulated rapid callus formation displaying a consistent monomodal strain profile whereas the bone volume fraction in the vicinity of magnesium-gadolinium alloys exhibited a minimum close to the interface of the implant and less ordered strain transfer. Correlations in our data suggest that implant stability benefits from disparate bone morphological properties depending on the biomaterial utilized. This leaves the choice of biomaterial as situational depending on local tissue properties.

10.
J Arthroplasty ; 38(7S): S280-S284, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37028774

RESUMEN

BACKGROUND: Total hip arthroplasty (THA) failure due to tribocorrosion of modular junctions and resulting adverse local tissue reactions to corrosion debris have seemingly increased over the past few decades. Recent studies have found that chemically-induced column damage seen on the inner head taper is enabled by banding in the alloy microstructure of wrought cobalt-chromium-molybdenum alloy femoral heads, and is associated with more material loss than other tribocorrosion processes. It is unclear if alloy banding represents a recent phenomenon. The purpose of this study was to examine THAs implanted in the 1990s, 2000s, and 2010s to determine if alloy microstructure and implant susceptibility to severe damage has increased over time. METHODS: Five hundred and forty-five modular heads were assessed for damage severity and grouped based on decade of implantation to serve as a proxy measure for manufacturing date. A subset of heads (n = 120) was then processed for metallographic analysis to visualize alloy banding. RESULTS: We found that damage score distribution was consistent over the time periods, but the incidence of column damage significantly increased between the 1990s and 2000s. Banding also increased from the 1990s to 2000s, but both column damage and banding levels appear to recover slightly in the 2010s. CONCLUSION: Banding, which provides preferential corrosion sites enabling column damage, has increased over the last 3 decades. No difference between manufacturers was seen, which may be explained by shared suppliers of bar stock material. These findings are important as banding can be avoidable, reducing the risk of severe column damage to THA modular junctions and failure due to adverse local tissue reactions.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Humanos , Prótesis de Cadera/efectos adversos , Vitalio , Aleaciones de Cromo/química , Artroplastia de Reemplazo de Cadera/efectos adversos , Cabeza Femoral/cirugía , Corrosión , Falla de Prótesis , Diseño de Prótesis , Cobalto
11.
Orthop Surg ; 15(5): 1219-1227, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36959773

RESUMEN

The spine is the most common site of bone metastases. Many cancer patients will ultimately develop spinal metastatic disease with symptomatic epidural spinal cord compression. At present, the main treatment for cervical spine tumors is surgical resection combined with postoperative radiotherapy. Implant materials for cervical spine anterior column reconstruction need to meet amounts of different properties, such as biocompatibility, bioactivity and the ability to maintain long-term mechanical strength. The selection of different materials determines the surgical efficacy and prognosis of patients to a certain extent. This article provides an overview of a variety of implant materials used for anterior column reconstruction after cervical spine tumor resection, introduces and analyzes their properties, advantages, disadvantages, derivatives, and applications in clinical practice, and looks forward to the future development of implant materials.


Asunto(s)
Neoplasias Óseas , Compresión de la Médula Espinal , Neoplasias de la Columna Vertebral , Humanos , Vértebras Cervicales/cirugía , Vértebras Cervicales/patología , Neoplasias Óseas/patología , Compresión de la Médula Espinal/cirugía , Neoplasias de la Columna Vertebral/secundario , Resultado del Tratamiento
12.
Biomater Transl ; 4(3): 151-165, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38283087

RESUMEN

The growing field of dental implant research and development has emerged to rectify the problems associated with human dental health issues. Bio-ceramics are widely used in the medical field, particularly in dental implants, ortho implants, and medical and surgical tools. Various materials have been used in those applications to overcome the limitations and problems associated with their performance and its impact on dental implants. In this article we review and describe the fabrication methods employed for ceramic composites, the microstructure analyses used to identify significant effects on fracture behaviour, and various methods of enhancing mechanical properties. Further, the collective data show that the sintering technique improves the density, hardness, fracture toughness, and flexural strength of alumina- and zirconia-based composites compared with other methods. Future research aspects and suggestions are discussed systematically.

13.
Biomater Res ; 26(1): 59, 2022 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-36274171

RESUMEN

In an aging society, quality of life improvement is emerging as an important issue, and as implants are accepted as the core of oral rehabilitation treatment, competition for leadership in developing related technologies is intensifying. In this trend, unlike what is evident in the literature, the patent landscape shows the status of industrial-based technology development. A database analysis of a total of 32,237 dental implant patents shows improvements in technology, diverse geographical characteristics, and new advances toward technological convergence in this field. Technologically, dental implant technology has shown a tendency to develop from conventional implant materials and surface treatment technologies to new material technologies making use of substances such as pure zirconium and tantalum or software technologies related to diagnosis and prognosis. Regionally, dental implant technology, which was developed mainly in Europe and the Unites States in the past, is growing explosively in East Asian countries accompanied by the recent growth of the Asian market. In summary, dental implant technology seems to be developing while trying to converge with various technological areas based on the local market environment. Therefore, it is necessary to develop a new dental implant material technology that is highly applicable to the development of hybrid information/communication technology and is suitable for a new manufacturing method. Our study may provide important information to help basic and translational researchers and their financial supporters set their research directions in advancing the development of dental implants.

14.
Dent Mater ; 38(9): 1547-1557, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35909000

RESUMEN

OBJECTIVES: This study aimed to investigate human osteoblasts (HOB) response towards different dental implant abutment materials. METHODS: Five dental implant abutment materials were investigated: (1) titanium (Ti), (2) titanium coated nitride (TiN), (3) cobalt chromium (CoCr), (4) zirconia (ZrO2), and (5) modified polyether ether ketone (m-PEEK). HOBs were cultured, expanded, and seeded according to the supplier's protocol (PromoCell, UK). Cell proliferation and cytotoxicity were evaluated at days 1, 3, 5, and 10 using Alamar Blue (alamarBlue) and lactate dehydrogenase (LDH) colorimetric assays. Data were analysed via two-way ANOVA, one-way ANOVA and Tukey's post hoc test (significance was determined as p < 0.05 for all tests). RESULTS: All the investigated materials showed high and comparable initial proliferation activities apart from ZrO2 (46.92%), with P% of 79.91%, 68.77%, 73.20%, and 65.46% for Ti, TiN, CoCr, and m-PEEK, respectively. At day 10, all materials exhibited comparable and lower P% than day 1 apart from TiN (70.90%) with P% of 30.22%, 40.64%, 37.27%, and 50.65% for Ti, CoCr, ZrO2, and m-PEEK, respectively. The cytotoxic effect of the investigated materials was generally low throughout the whole experiment. At day 10, the cytotoxicity % was 7.63%, 0.21%, 13.30%, 5.32%, 8.60% for Ti, TiN, CoCr, ZrO2, and m-PEEK. The Two-way ANOVA and Tukey's Multiple Comparison Method highlighted significant material and time effects on cell proliferation and cytotoxicity, and a significant interaction (p < 0.0001) between the tested materials. Notably, TiN and m-PEEK showed improved HOB proliferation activity and cytotoxic levels than the other investigated materials. In addition, a non-significant negative correlation between viability and cytotoxicity was found for all tested materials. Ti (p = 0.07), TiN (p = 0.28), CoCr (p = 0.15), ZrO2 (p = 0.17), and m-PEEK (p = 0.12). SIGNIFICANCE: All the investigated materials showed excellent biocompatibility properties with more promising results for the newly introduced TiN and m-PEEK as alternatives to the traditionally used dental implant and abutment materials.


Asunto(s)
Implantes Dentales , Circonio , Humanos , Pilares Dentales , Materiales Dentales/toxicidad , Cetonas/farmacología , Ensayo de Materiales , Osteoblastos , Polietilenglicoles/toxicidad , Titanio/toxicidad , Circonio/toxicidad
15.
Front Bioeng Biotechnol ; 10: 895288, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35646862

RESUMEN

Due to excellent mechanical properties and similar elastic modulus compared with human cortical bone, polyetheretherketone (PEEK) has become one of the most promising orthopedic implant materials. However, implant-associated infections (IAIs) remain a challenging issue since PEEK is bio-inert. In order to fabricate an antibacterial bio-functional surface, modifications of PEEK had been widely investigated. This review summarizes the modification strategies to biofunctionalize PEEK for antibacterial. We will begin with reviewing different approaches, such as surface-coating modifications and controlled release of antimicrobials. Furthermore, blending modifications and 3D printing technology were discussed. Finally, we compare the effects among different approaches. We aimed to provide an in-depth understanding of the antibacterial modification and optimize the design of the PEEK orthopedic implant.

16.
Mater Today Bio ; 15: 100326, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35761844

RESUMEN

In tissue engineering, foreign body reactions (FBRs) that may occur after the insertion of medical implants are a considerable challenge. Materials currently used in implants are mainly metals that are non-organic, and the lack of biocompatibility and absence of immune regulations may lead to fibrosis after long periods of implantation. Here, we introduce a highly biocompatible hybrid interface of graphene oxide (GO) and collagen type I (COL-I), where the topological nanostructure can effectively inhibit the differentiation of fibroblasts into myofibroblasts. The structure and roughness of this coating interface can be easily adjusted at the nanoscale level through changes in the GO concentration, thereby effectively inducing the polarization of macrophages to the M1 state without producing excessive amounts of pro-inflammatory factors. Compared to nanomaterials or the extracellular matrix as an anti-fibrotic interface, this hybrid bio-interface has superior mechanical strength, physical structures, and high inflammation. Evidenced by inorganic materials such as glass, titanium, and nitinol, GO-COL shows great potential for use in medical implants and cell-material interfaces.

17.
Materials (Basel) ; 14(19)2021 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-34640231

RESUMEN

Implants and materials are indispensable in trauma and orthopedic surgery. The continuous improvements of implant design have resulted in an optimized mechanical function that supports tissue healing and restoration of function. One of the still unsolved problems with using implants and materials is infection. Trauma and material implantation change the local inflammatory situation and enable bacterial survival and material colonization. The main pathogen in orthopedic infections is Staphylococcus aureus. The research efforts to optimize antimicrobial surfaces and to develop new anti-infective strategies are enormous. This mini-review focuses on the publications from 2021 with the keywords S. aureus AND (surface modification OR drug delivery) AND (orthopedics OR trauma) AND (implants OR nails OR devices). The PubMed search yielded 16 original publications and two reviews. The original papers reported the development and testing of anti-infective surfaces and materials: five studies described an implant surface modification, three developed an implant coating for local antibiotic release, the combination of both is reported in three papers, while five publications are on antibacterial materials but not metallic implants. One review is a systematic review on the prevention of stainless-steel implant-associated infections, the other addressed the possibilities of mixed oxide nanotubes. The complexity of the approaches differs and six of them showed efficacy in animal studies.

18.
Mater Sci Eng C Mater Biol Appl ; 126: 112128, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34082945

RESUMEN

According to the National Center for Health Statistics, currently, more than 250,000 total hip replacements annually in the US alone, with an estimated increase to 500,000 by the year 2030. The usage of tapered junctions between the femoral neck and head gives the surgeon flexibility in implant assembly. However, these modular junctions are subjected to micro-motion that may cause chemical and fretting-corrosion at the modular junction. Therefore, it is imperative to study these forces to mitigate their effects. The current study aims to understand the effects of fretting-corrosion as a function of fretting frequencies caused by common physical activities in an in-vitro model of hip modular junctions. The fretting system has a tribological contact condition of flat-on-flat, mounted to a load frame. CoCrMo pins were polished and immersed in a synovial fluid-like electrolyte solution (Bovine calf serum 30 g/l). Electrochemical measurements were made using a potentiostat. Samples then undergo 3600 cycles at 50 µm (to simulate gross slips), with a horizontal load at 200 N, and a frequency of 0.5 Hz, 0.7 Hz, 1 Hz, and 1.5 Hz to simulate Sit Down-Stand Up, Stair Climb, Walking, and Jogging, respectively. Worn surfaces were then examined under optical and scanning electron microscopy. The evolution of free potential as a function of time for tested frequencies shows the initial potential drop and stabilized trend in the potential evolution. The sample group at a higher frequency displays a higher tendency of corrosion than a lower frequency; however, the dissipation energy decreases as a function of fretting frequency. Both electrochemical and mechanical responses correlate to the variation in the fretting frequencies. Organometallic complexes were found on the surfaces of the samples that were subjected to a slower frequency of fretting, whereas mechanical grooving was noticed on samples with a faster frequency. Hence, these preliminary studies suggest that implant failure rates may be altered based on fretting-frequencies induced by physical activity. Further studies will be required to verify the findings and explore the potential role of fretting frequency in the damage modes of the modular junction.


Asunto(s)
Artroplastia de Reemplazo de Cadera , Prótesis de Cadera , Animales , Bovinos , Corrosión , Ensayo de Materiales , Diseño de Prótesis , Falla de Prótesis , Propiedades de Superficie
19.
Materials (Basel) ; 14(8)2021 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-33924189

RESUMEN

Total knee replacement (TKR) is a remarkable achievement in biomedical science that enhances human life. However, human beings still suffer from knee-joint-related problems such as aseptic loosening caused by excessive wear between articular surfaces, stress-shielding of the bone by prosthesis, and soft tissue development in the interface of bone and implant due to inappropriate selection of TKR material. The choice of most suitable materials for the femoral component of TKR is a critical decision; therefore, in this research paper, a hybrid multiple-criteria decision-making (MCDM) tactic is applied using the degree of membership (DoM) technique with a varied system, using the weighted sum method (WSM), the weighted product method (WPM), the weighted aggregated sum product assessment method (WASPAS), an evaluation based on distance from average solution (EDAS), and a technique for order of preference by similarity to ideal solution (TOPSIS). The weights of importance are assigned to different criteria by the equal weights method (EWM). Furthermore, sensitivity analysis is conducted to check the solidity of the projected tactic. The weights of importance are varied using the entropy weights technique (EWT) and the standard deviation method (SDM). The projected hybrid MCDM methodology is simple, reliable and valuable for a conflicting decision-making environment.

20.
J Biomed Mater Res A ; 109(1): 31-41, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-32418271

RESUMEN

Photofunctionalization of implant materials with ultraviolet (UV) radiation have been subject of study in the last two decades, and previous research on CoCrMo discs have showed good results in terms of bioactivity and the findings of apatite-like crystals in vitro. In the current study, CoCrMo domes were photofunctionalized with UV radiation of 254 nm on their internal faces during 24 hr; they were implanted in rabbit tibia and remained for 3, 4, and 6 weeks. The potential to induce bone formation beneath the dome-shaped membranes was evaluated through morphometric, histologic, and density measurements; and the results were compared with those obtained under control untreated domes. Higher density values were observed for irradiated domes at 3 weeks, whereas higher volumes were obtained under photofunctionalized domes for longer periods (4 and 6 weeks). Histologically, woven bone was formed by endochondral ossification in all cases; differences in the architecture and size of the trabeculae and in the number of osteoblasts were noted between irradiated and non-irradiated samples. The UV radiation of 254 nm generated a larger bone volume fraction compared to that found in the absence of UVC radiation and induced an increase of density in the early stages of healing, leading to a better initial bone quality and improved osseointegration.


Asunto(s)
Regeneración Ósea/efectos de los fármacos , Aleaciones de Cromo/farmacología , Aleaciones de Cromo/efectos de la radiación , Ingeniería de Tejidos/métodos , Animales , Interfase Hueso-Implante , Condrocitos/efectos de los fármacos , Masculino , Membranas Artificiales , Oseointegración , Osteoblastos/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Conejos , Tibia/efectos de los fármacos , Tibia/crecimiento & desarrollo , Rayos Ultravioleta
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