Implants porous

Yang, Z., Yuan, H., Tong, W., Zou, P., Chen, W., and Zhang, X., Osteogenesis in extraskele-tally implanted porous calcium phosphate ceramics Variability among different kinds of animals. Biomaterials 17,2131-2137 (1996). 

Figure 4.4 M t Zero-order controlled release profile of a reservoir-type nondegradable polymeric implant (porous or compact membrane)...

IMPURITY STATES IN IMPLANTED POROUS ANODIC ALUMINA... 

Table IV. njmorigenesls In Rats by Implanted Porous Polyethylene with and without Immobilized Collagen...

Li Q, Ricardo A, Benner SA, Winefordner JD, Powell DH (2005) Desorption/ionization on porous silicon mass spectrometry studies on pentose-borate complexes. Anal Chem 77 4503-4508 Liu W, Zhang M, Lin C, Zeng Z, Wang L, Chu PK (2001) Intense blue-light emission from carbon-plasma-implanted porous silicon. Appl Phys Lett 78(l) 37-39... 

Dantas MOS, Galeazzo E, Peres HEM et al (2008) Silicon field-emission devices fabricated using the hydrogen implantation-porous silicon (HI-PS) micromachining technique. J Microelectromech Syst 17(5) 1263-1269... 

Laschke MW, Schank TE, Scheuer C, Kleer S, Shadmanov T, Eglin D, et al. In vitro osteogenic differentiation of adipose-derived mesenchymal stem cell spheroids impairs their in vivo vascularization capacity inside implanted porous polyurethane scaffolds. Acta Biomater October 2014 10(10) 4226-35. 

Porous and inert bioceramic The bond to the bone is mechanical and the fixation is biological. The growth of the bone takes place through the pores of implants. Porous polycrystalline alumina is also a typical example of the group. 

There are, however, continuing difficulties for catalytic appHcations of ion implantation. One is possible corrosion of the substrate of the implanted or sputtered active layer this is the main factor in the long-term stabiHty of the catalyst. Ion implanted metals may be buried below the surface layer of the substrate and hence show no activity. Preparation of catalysts with high surface areas present problems for ion beam techniques. Although it is apparent that ion implantation is not suitable for the production of catalysts in a porous form, the results indicate its strong potential for the production and study of catalytic surfaces that caimot be fabricated by more conventional methods. 

The next advance in total hip arthroplasty came with the development of various porous surface treatments which allow bone tissue to grow into the metal porous coating on the femoral stem of the hip implant and on the acetabular component of the total joint replacement. These developments arose because of patients who were not able to tolerate cemented implants because of allergies to the cement, methylmethacrylate. More youthflil patients are better served by a press-fit implant as well. Figure 12 shows the difference between textured and beaded surface-treated orthopedic prostheses. 

Surface preparation of the dental implant prior to implantation wiH have an effect on corrosion behavior, initial metal ion release, and interface tissue response (316). The titanium and titanium aHoy dental implants in present use have many forms to assist bone ingrowth attachment including cylinders with holes, screw threaded surfaces, porous surfaces, and other types of roughened surfaces. Methods used to produce porous surfaces iaclude arc plasma... 

Subperiosteal. The subperiosteal implants are placed on the residual bony ridge and are not osseointegrated. This implant is most commonly used in the mandible but sometimes is used in the maxilla. Subperiosteal implants have been installed since the 1940s (311) and still have a success rate after five years of only 50 to 60%. A success rate of over 90% for five years and 50% for 15 years also has been quoted (312). Subperiosteal implants are fitted by casting, which is an individual procedure. The casting can be coated with a porous metal coating or other coating and then put in the patient. This may result in an improvement for these implants. 

Method for total immersion corrosion test for tank-type aircraft maintenance chemicals Method for total immersion corrosion test for aircraft maintenance chemicals Practice for assessment of compatibility of bio-materials (non-porous) for surgical implants with respect to effect of materials in muscle and bone... 

Du C, Meijer GJ, van de Valk C, Haan Re, Bezemer JM, Hesseling SC, Cui FZ, de Groot K, and Layrolle P. Bone growth in biomimetic apatite coated porous Polyactive 1000PEGT70PBT30 implants. Biomaterials, 2002, 23,4649-4656. 

R. A. Replamineform Porous Biomaterials for Hard Tissue Implants. J. BiomecL Mater. Res. Symp. 1975, 6, 23-27. f... 

Ethylene vinyl acetate has also found major applications in drug delivery. These copolymers used in drug release normally contain 30-50 wt% of vinyl acetate. They have been commercialized by the Alza Corporation for the delivery of pilocarpine over a one-week period (Ocusert) and the delivery of progesterone for over one year in the form of an intrauterine device (Progestasert). Ethylene vinyl acetate has also been evaluated for the release of macromolecules such as proteins. The release of proteins form these polymers is by a porous diffusion and the pore structure can be used to control the rate of release (3). Similar nonbiodegradable polymers such as the polyurethanes, polyethylenes, polytetrafluoroethylene and poly(methyl methacrylate) have also been used to deliver a variety of different pharmaceutical agents usually as implants or removal devices. 

Fig. 1.6 (A and B) Scanning electron micro- implantation in the bone marrow showing for-graphs of the porous hydroxyapatite-collagen mation of new bone (white asterisk) attached nanocomposite scaffolds at different magnifi- directly to the nanocomposite (asterisk). Arrows cations. Arrowheads in B indicate the hydroxy- indicate cuboidal osteoblasts on the surface of apatite nanocrystals on the collagen fibrils. new bone. Adapted from [94], reproduced by Histology at (C) 1 week and (D) 4 weeks after permission of Wiley-VCH.

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