scholarly journals Oxide Bioceramic Composites in Orthopedics and Dentistry

2021 ◽  
Vol 5 (8) ◽  
pp. 206
Author(s):  
Piconi Corrado ◽  
Sprio Simone
Keyword(s):  
Mechanical Behavior ◽  
Hip Replacement ◽  
Ceramic Composites ◽  
Clinical Applications ◽  
Wide Field ◽  
Joint Replacements ◽  
Composite Systems ◽  
Third Phase ◽  
Main Component ◽  
Zirconia Toughened Alumina

Ceramic composites based on alumina and zirconia have found a wide field of application in the present century in orthopedic joint replacements, and their use in dentistry is spreading. The development of this class of bioceramic composites was started in the 1980s, but the first clinical applications of the total hip replacement joint were introduced in the market only in the early 2000s. Since then, several composite systems were introduced in joint replacements. These materials are classified as Zirconia-Toughened Alumina if alumina is the main component or as Alumina-Toughened Zirconia when zirconia is the main component. In addition, some of them may contain a third phase based on strontium exa-aluminate. The flexibility in device design due to the excellent mechanical behavior of this class of bioceramics results in a number of innovative devices for joint replacements in the hip, the knee, and the shoulder, as well in dental implants. This paper gives an overview of the different materials available and on orthopedic and dental devices made out of oxide bioceramic composites today on the market or under development.

scholarly journals POS1143 GOUT AND JOINT REPLACEMENTS IN THE US

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 851.1-851
Author(s):  
G. Singh ◽  
M. Sehgal ◽  
A. Mithal
Keyword(s):  
Knee Joint ◽  
Confidence Intervals ◽  
Knee Replacement ◽  
Joint Replacement ◽  
Economic Burden ◽  
Hip Replacement ◽  
Average Charge ◽  
Joint Replacements ◽  
Increased Risk ◽  
The Us

Background:Irreversible joint damage in gout has been linked to a possible increase in knee and hip joint replacements1. In addition, the strong association between gout and osteoarthritis2,3 could also lead to an increased risk of joint replacements in patients with gout. Population-based data from the UK and Taiwan have shown hazard rates of 1.14 and 1.16 respectively for knee replacements in patients with gout compared to age and gender matched controls1. However, there is little national data in the US on clinical and economic burden of joint replacements in patients with gout.Objectives:To evaluate total or partial hip and knee joint replacements in patients with gout in the US and to estimate their economic impactMethods:The Nationwide Inpatient Sample (NIS) is a stratified random sample of all US community hospitals. It is the only US national hospital database with information on all patients, regardless of payer, including persons covered by Medicare, Medicaid, private insurance, and the uninsured. Detailed information including clinical and nonclinical data elements on each hospital stay including International Classification of Diseases (ICD)10 diagnosis and procedure codes, age, gender, length of stay, payer, charges, comorbidities etc. is available. We examined hospitalizations in patients with gout with hip and knee joint replacements in NIS 2018, the most recent year of data.Results:In 2018, there were 914,510 hospitalizations with primary or secondary diagnosis of gout in the US. Of these 43,615 were for joint replacement surgeries (knee (24,840) and hip (18,755)). Patients with knee replacement were on an average 68.5 years old (95% confidence intervals 68.2 years -68.8 years). Patients with hip replacement were slightly older (mean age 70.3 years, 95% confidence intervals 69.8 years -70.7 years). Unlike general population statistics, men formed a majority of these joint replacements (68% for the knee and 72% for the hip). The average charge per hospitalization was $69,279 and $72,944 for knee and hip replacement respectively. The total annual national cost estimate was $3.09 billion, with government insurances (Medicare and Medicaid) responsible for 67% of knee replacement and 70% of hip replacement costs.Conclusion:Joint replacements in gout patients have a large clinical and economic burden in the US. This calls for an increased awareness and management of associated hip and knee arthritis in patients with gout.References:[1]Kuo CF, Chou IJ, See LC, et al. Urate-lowering treatment and risk of total joint replacement in patients with gout. Rheumatology. Dec 1 2018;57(12):2129-2139.[2]Howard RG, Samuels J, Gyftopoulos S, et al. Presence of gout is associated with increased prevalence and severity of knee osteoarthritis among older men: results of a pilot study. Journal of clinical rheumatology: practical reports on rheumatic & musculoskeletal diseases. Mar 2015;21(2):63-71.[3]Roddy E, Zhang W, Doherty M. Are joints affected by gout also affected by osteoarthritis? Annals of the rheumatic diseases. Oct 2007;66(10):1374-1377.Disclosure of Interests:Gurkirpal Singh Shareholder of: Pfizer, Merck, Sanofi, Grant/research support from: Horizon, Maanek Sehgal: None declared, Alka Mithal: None declared.

Processing and mechanical behavior of rigid and flexible material composite systems formed via voxel digital design in polyjet additive manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Furkan Ulu ◽  
Ravi Pratap Singh Tomar ◽  
Ram Mohan
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Additive Manufacturing ◽  
Mechanical Behavior ◽  
Digital Design ◽  
Composite Part ◽  
Content Type ◽  
Composite Systems ◽  
Polyjet Printing ◽  
Material Composite

Purpose PolyJet technology allows printing complex multi-material composite configurations using Voxel digital designs' capability, thus allowing rapid prototyping of 3D printed structural parts. This paper aims to investigate the processing and mechanical characteristics of composite material configurations formed from soft and hard materials with different distributions and sizes via voxel digital print design. Design/methodology/approach Voxels are extruded representations of pixels and represent different material information similar to each pixel representing colors in digital images. Each geometric region of a digitally designed part represented by a voxel can be printed with a different material. Multi-material composite part configurations were formed and rapidly prototyped using a PolyJet printer Stratasys J750. A design of experiments composite part configuration of a soft material (Tango Plus) within a hard material matrix (Vero Black) was studied. Composite structures with different hard and soft material distributions, but at the same volume fractions of hard and soft materials, were rapidly prototyped via PolyJet printing through developed Voxel digital printing designs. The tensile behavior of these formed composite material configurations was studied. Findings Processing and mechanical behavior characteristics depend on materials in different regions and their distributions. Tensile characterization obtained the fracture energy, tensile strength, modulus and failure strength of different hard-soft composite systems. Mechanical properties and behavior of all different composite material systems are compared. Practical implications Tensile characteristics correlate to digital voxel designs that play a critical role in additive manufacturing, in addition to the formed material composition and distributions. Originality/value Results clearly indicate that multi-material composite systems with various tensile mechanical properties could be created using voxel printing by engineering the design of material distributions, and sizes. The important parameters such as inclusion size and distribution can easily be controlled within all slices via voxel digital designs in PolyJet printing. Therefore, engineers and designers can manipulate entire morphology and material at each voxel level, and different prototype morphologies can be created with the same voxel digital design. In addition, difficulties from AM process with voxel printing for such material designs is addressed, and effective digital solutions were used for successful prototypes. Some of these difficulties are extra support material or printing the part with different dimension than it designed to achieve the final part dimension fidelity. Present work addressed and resolved such issued and provided cyber based software solutions using CAD and voxel discretization. All these increase broad adaptability of PolyJet AM in industry for prototyping and end-use.

Structure Evolution in Al2O3 - ZrO2(Y2O3) Ceramic Composites during Sintering

2010 ◽  
Vol 65 ◽  
pp. 11-15
Author(s):  
Ya. Dyatlova ◽  
S.S. Ordanyan ◽  
Andrey Osmakov ◽  
V. Pesin ◽  
V. Rumyantsev
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Composite ◽  
Large Angle ◽  
Tetragonal Zirconia ◽  
Ceramic Composites ◽  
Structure Evolution ◽  
Composite Ceramics ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
Microstructure Parameters

The paper demonstrates the possibility to control the degree of tetragonal zirconia stabilization, microstructure and physical and mechanical behavior of Al2O3 -ZrO2(Y2O3) ceramic composite. Control is exerted via the process variables during deposition synthesis of nanosized composite powders from hydroxide salts, and their subsequent heat treatment and consolidation. Morphology features of nanosized powder systems and microstructures of the consolidated nanostructured materials were characterized by BET surface are measurements, scanning electron microscopy (both standard and HR), and large-angle X-ray diffraction. Correlations are established between microstructure parameters, physical and mechanical behavior of composite ceramics and a degree of stabilization of tetragonal ZrO2.

The Effect of Ta2O5 on the Densification Behaviour and Mechanical Properties of Zirconia-Toughened Alumina (ZTA) Composites Prepared by Two-Stage Sintering

2020 ◽  
Vol 861 ◽  
pp. 320-326
Author(s):  
Teow Hsien Loong ◽  
Se Yong Eh Noum ◽  
Wong Wai Mun
Keyword(s):  
Mechanical Properties ◽  
Hip Replacement ◽  
Sintering Temperature ◽  
Tantalum Oxide ◽  
Well Being ◽  
Two Stage ◽  
Total Hip ◽  
Second Stage ◽  
Replacement Procedure ◽  
Zirconia Toughened Alumina

By 2050, 130 million people are estimated to suffer from osteoarthritis worldwide which would require patients to undergo total hip replacement procedure which have a lifespan of 20 years and failure rates of ~1%. In this research, Zirconia Toughened Alumina (ZTA) which is the main biomaterial used for total hip arthroplasty were doped with varying vol % of Tantalum Oxide (Ta2O5) from 0 to 0.4 vol % were produced through conventional two-stage sintering with first stage sintering temperature, ranging between 1400°C and 1550°C, heated at 20°C/min, followed by second stage sintering temperature of 1350°C and hold for 12 hours. The efficacy of two-stage sintering on the microstructure and mechanical properties of the sintered samples were then evaluated. Addition of Ta2O5 combined with two-stage sintering were able to produce ZTA composites with enhanced grain size and mechanical properties compared to undoped ZTA composites. The samples with 0.3 vol% Ta2O5 content and above sintered at T1 ≥1450°C achieved density > 99% T.D., Vickers hardness > 19 GPa, Young’s modulus > 400 GPa and fracture toughness > 6 MPam1/2 when compared to undoped ZTA composites. This would enable production of ZTA with improved mechanical properties and lifespan ensuring the well-being of people suffering from osteoarthritis.

scholarly journals Use of prescription analgesic drugs before and after hip or knee replacement in patients with osteoarthritis

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Tuomas J. Rajamäki ◽  
Pia A. Puolakka ◽  
Aki Hietaharju ◽  
Teemu Moilanen ◽  
Esa Jämsen
Keyword(s):  
Knee Replacement ◽  
Joint Replacement ◽  
Hip Replacement ◽  
Drug Prescription ◽  
Considerable Proportion ◽  
Joint Replacements ◽  
Analgesic Drugs ◽  
Before And After ◽  
Hip Replacements ◽  
Strong Opioids

Abstract Background Analgesic drugs are recommended to treat pain caused by osteoarthritis, and joint replacement should decrease the need for them. We aimed to determine the user rates of analgesic drugs before and after joint replacement. Methods All patients who underwent a primary hip or knee replacement for osteoarthritis from 2002 to 2013 in a region of 0.5 million people were identified. Patients with revision or other joint replacements during the study period (operation date +/− two years) were excluded, leaving 6238 hip replacements (5657 patients) and 7501 knee replacements (6791 patients) for analyses. Medication data were collected from a nationwide Drug Prescription Register and the prevalence (with its 95% confidence intervals) of acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), mild opioids, strong opioids, and medications used for neuropathic pain was calculated in three-month periods two years before and after surgery. Results Between two years and three months preoperatively, the proportion of patients who redeemed at least one type of analgesic drug increased from 28% (95% CI, 27–30%) to 48% (47–50%) on hip replacement patients and from 33% (32–34%) to 41% (40–42%) on knee replacement patients. Postoperatively, the proportions decreased to 23% (22–24%) on hip and to 30% (29–31%) on knee patients. Hip replacement patients used more NSAIDs (34% (32–35%) hip vs 26% (25–27%) knee, p < 0.001), acetaminophen (14% (13–15%) vs 12% (11–13%), p < 0.001), and mild opioids (14% (13–15%) vs 9% (8–9%), p < 0.001) than knee patients preoperatively, but postoperatively hip patients used less NSAIDs (12% (11–13%) vs 16% (15–16%), p < 0.001), acetaminophen (9% (8–10%) vs 11% (11–12%), p < 0.001), and mild opioids (5% (5–6%) vs 8% (7–8%), p < 0.001). Conclusion Use of analgesic drugs increases prior to joint replacement, and is reduced following surgery. However, a considerable proportion of patients continue to use analgesics in two-year follow-up.

scholarly journals Microstructure Characteristics of Ce-ZTA Ceramic Composites Obtained by Liquid Phase Sintering

2006 ◽  
Vol 530-531 ◽  
pp. 421-424
Author(s):  
Haine Beck ◽  
Maria do Carmo de Andrade Nono ◽  
Francisco Piorino Neto
Keyword(s):  
Ceramic Composite ◽  
Glassy Phase ◽  
Volume Fraction ◽  
Tetragonal Zirconia ◽  
Ceramic Composites ◽  
Liquid Phase Sintering ◽  
Scanning Electronic Microscopy ◽  
Powder Samples ◽  
Zirconia Toughened Alumina ◽  
Crystalline Matrix

Zirconia-toughened alumina (ZTA) ceramics with Ce-TZP (tetragonal zirconia polycrystalline doped with ceria) volume fraction on 33% were prepared with the addition.. The influence of glass infiltrated method was investigated. Coprecipitated Zr and Ce hydroxide mixture was obtained from ZrOCl2.8H2O and CeCl3. 7H2O aqueous solution. CeO2-ZrO2 calcinated powder was compacted and the compacted samples were sintered at 1180°C. Powder samples were characterized by scanning electronic microscopy (SEM), The volume fraction of each phase, the grains size and shapes, and the porosity were investigated with SEM. The relative density and shrinkage was investigate too. The results showed that the crystalline matrix was composed by SiO2 -B2O3-La2O3-Al2O3-Ce-TZP and revealed the important role played the glassy phase in the densification of this ceramic composite.

Mechanical Behavior of Multilayered Nanoscale Metal-Ceramic Composites

2005 ◽  
Vol 7 (12) ◽  
pp. 1099-1108 ◽  
Author(s):  
X. Deng ◽  
N. Chawla ◽  
K. K. Chawla ◽  
M. Koopman ◽  
J. P. Chu
Keyword(s):  
Mechanical Behavior ◽  
Ceramic Composites ◽  
Metal Ceramic

scholarly journals Nacre-like Alumina Composites Based on Heteroaggregation

2020 ◽  
Author(s):  
Mariana Muñoz ◽  
Manuella Cerbelaud ◽  
Arnaud Videcoq ◽  
Hassan Saad ◽  
Alexandre Boulle ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Mechanical Behavior ◽  
Colloidal Suspensions ◽  
High Strength ◽  
Ceramic Composites ◽  
Anisotropic Particles ◽  
High Toughness ◽  
High Stiffness ◽  
Brick And Mortar ◽  
Alumina Composites

<div> <div> <div> <p>High strength and high toughness are usually mutually exclusive in materials. Among all material classes, ceramics exhibit a high stiffness and strength, but they present a limited plastic deformation, which results in a moderate toughness. However, tough ceramics have been obtained using anisotropic particles organized in a "brick and mortar" microstructure, inspired by the structure of the natural nacre. Here, we propose to build nacre-like ceramic composites from colloidal suspensions using heteroaggregation of particles. Two different shaping processes are used: direct settling of suspensions or freeze-granulation. After sintering, in both cases, the platelets alignment is very good, close to that of platelets in natural nacre, with a slightly better one noted for direct settling. Despite a better platelet alignment, the toughness is lower than in previous studies showing that further improvement of the interfacial phases present in the material must now be considered to reinforce its mechanical behavior. </p> </div> </div> </div>

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