ISSN:0021-9304    

DOI:10.1002/jbm.820221202

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820221203

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820221204

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractCeramics composed of aluminum, calcium, and phosphorus oxides (ALCAP) were tested for compatibility as bone replacement biomaterials. Implantation of ALCAP ceramics in rat femurs had no deleterious effect on body weights, organ/body weight ratios, muscle, bone, blood, and kidney function. Aluminum resorbed from ALCAP ceramic bone implants was excreted in the urine and was not deposited in adjacent muscle. Plasma levels of aluminum were not elevated in rats implanted with ALCAP ceramics. Alkaline phosphatase activity of excised implant sites indicated greater bone formation in ALCAP ceramic implants than in bone autografts. Radiographs and implant histology demonstrated excellent bone association with implants and ingrowth of new bone into ALCAP ceramic implants. ALCAP ceramics are biocompatible and suitable for reconstruction of bone.

ISSN:0021-9304    

DOI:10.1002/jbm.820221205

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractImplants for hard tissue replacement have evolved over the last few decades, but a critical assessment of their design reveals that most dental implants and most orthopedic appliances for any given indication are basically similar in design to their commercial competitors. Some unique features are contained in the outer 0.7 mm, but shadow pictures of the devices could almost be superimposed upon one another. Near‐optimal designs have evolved for the materials systems commonly in use. The fight to minimize initial instability of implants, which leads to failure, has caused certain attachment mechanisms to emerge as acceptable, based upon research that indicates firm fixation in bone has resulted in longer average implant lifetime. The problem of initial stabilization is one of materials and design, both of which are necessary for a successful implant system. The nonmetallic calcium phosphate glass and ceramics technology available today provides materials that may counteract the effects of initial device instability by not relying on mechanical means of retention, alone, but chemical as wel

ISSN:0021-9304    

DOI:10.1002/jbm.820221206

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractBone tissue ingrowth in porous materials is enhanced by the deposition of bioactive calcium phosphate ceramic linings onto the pore walls. These bioactive coatings can be deposited using several methods which yield a variety of coating efficiencies and thereby influence the mechanisms and kinetics of ion release from the metal. We analyzed the effect of plasmaspraying hydroxyapatite onto titanium and cobalt–chromium alloys by measuring the release of Ti, Al, V, Co, and Crin vitro. Plasma‐sprayed coatings significantly reduced the Ti and Al release from titanium‐based alloy specimens. The tendencies of release from the cobalt‐based specimens are less pronounced. The data substantiate that neither localized enhanced passive dissolution of metal ions nor ceramic shielding of the metal occurs. The Scanning Auger Electron Microprobe Spectroscopic data suggest that the dissipation of thermal and kinetic energy of the ceramic particle at the time of impact can produce compositional and structural changes in the metal surfaces. The resulting effects are significant for the titanium alloy but less significant for the Co–Cr all

ISSN:0021-9304    

DOI:10.1002/jbm.820221207

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820221208

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe clinical use of a new ceramic composite material made up of multilayered alumina beads and adhered to a ceramic surface with a high‐temperature‐melting bioglass is proposed. The result is a structure characterised by a 27% porosity and an average pore diameter of 400 μm. The actual structure of the parts as well as their interface interaction were determined by Raman laser. The mechanical resistance of the adherence of this coating for the ceramic substratum was good enough to resist the stress to which it was submitted when used for a new model of prosthetic acetabulum. Experiments with rabbits revealed the good biocomatibility of the composite. The osteoproductive activity of the tissue surrounding the implant led to the gradual filling of the porosity with trabecular structures. The preliminary results of the clinical experience which began in November 1985, confirm the good compatibility of the ceramic compo

ISSN:0021-9304    

DOI:10.1002/jbm.820221209

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe purpose of this article was to review the laboratory and clinical performances since 1970 of a total hip prosthesis using alumina–alumina combination. The chemical and physical properties of dense alumina ceramic were studied in relation to biocompatibility, mechanical strength, and surface properties. Through the examination of 35 retrieved implants, it was found that the long‐term success of alumina–alumina total hip replacement depends on both the ceramic microstructure (small grain size with uniform distribution, minimum porosity, absence of inclusions) and implant geometry (sphericity deviation ±1 μm, radius tolerance between components 7–10 μm). Alumina component wear and fractures have disappeared with the use of high‐performance materials and severe manufacturing quality control. Examination of human biopsies from well‐fixed prostheses showed that alumina particles deposits increase with time with only a low‐grade macrophagic reaction. When loosening occurred, an inflammatory reaction appeared; this reaction was less striking than with loose metal–polyethylene prostheses, however. The long‐term behavior of cementless alumina cup fixation depends upon initial positioning and stability; survivorship analysis of the cemented ceramic cups showed an 88% survival probability after 8 years with a 1.6% average annual probability of revision. The percentage of surviving was 100% after 8 years in patients who were less than 50 years old. Aseptic loosenings occurring at the cup–cement interface were assumed to be related to stress protection secondary to the high rigidity of the ceramic leading to a weakening of the spongious bone supporting the cement mantle. Good bone stock quality as well as high‐quality ceramic appear to be the prerequisites for durable fix

ISSN:0021-9304    

DOI:10.1002/jbm.820221210

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY

摘要:

AbstractSolid and granular porous hydroxylapatite implants were compared in the surgical treatment of angular interproximal periodontal defects in 10 subject. After completion of initial therapy, presurgical measurements of pocket depth, attachment level, gingival recession, gingival fluid and tooth mobility were recorded. Six months after the surgery the measurements were repeated. The use of both forms of porous hydroxylapatite resulted in reduction in pocket depth, and probebale attachment level gains as well as gingival recession and reduction of gingival fluid and tooth mobility. These changes were similar for both granular and solid forms of porous hydroxylapatite.

ISSN:0021-9304    

DOI:10.1002/jbm.820221211

出版商:John Wiley&Sons, Inc.    

年代:1988

数据来源: WILEY