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Rønold HJ, Ellingsen JE. The use of a coin shaped implant for direct in situ measurement of attachment strength for osseointegrating biomaterial surfaces. Biomaterials 2002; 23:2201-9. [PMID: 11962661 DOI: 10.1016/s0142-9612(01)00353-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Most animal models currently used to study the retention of implants in bone are influenced by shear forces introduced during the retention test. This is mainly due to the implant design, which most often are cylindrical, conical or threaded. In these models interlocking between bone and implant surface will increase the effect of genuine bone bonding and thus give a false positive outcome. The purpose of the present study was to establish a model for testing functional attachment of implants in situ, with minimal influence of interlocking and shear forces. The model involves the use of flat coin shaped implant placed onto the cortical bone of rabbit tibia without mechanical fixation to the bone. The implant is passively retained on the cortical bone by a titanium band retainer. During the healing period, the contact between the coin shaped implants and the bone is restricted to the flat test surfaces. To prevent interlocking effects from lateral bone attachments a polytetrafluoroethylene (PTFE) cap covering the vertical and the upper faces of the implants were used. The tensile test was performed with a gradual, calibrated pull, perpendicular to the bone-implant interface. This pullout model makes it possible to study the kinetics and strength of bone bonding with negligible influence of shear forces or mechanical interlocking.
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Affiliation(s)
- Hans Jacob Rønold
- Dental Faculty, Department of Prosthetics and Oral Function, University of Oslo, Norway
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52
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Svehla M, Morberg P, Bruce W, Zicat B, Walsh WR. The effect of substrate roughness and hydroxyapatite coating thickness on implant shear strength. J Arthroplasty 2002; 17:304-11. [PMID: 11938506 DOI: 10.1054/arth.2002.30410] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
This study examined the role of substrate preparation and hydroxyapatite (HA) coating thickness on bone ongrowth and shear strength in a bilateral bicortical sheep model. Plasma-sprayed and grit-blasted titanium implants with different thickness HA coatings were examined at 4, 8, 12, and 26 weeks after implantation. Shear strength increased with time for all implants. Plasma-sprayed implants were superior to grit-blasted implants at all time points. The 100-microm-thick HA layer used in the present study provided greater fixation and ongrowth and less resorption compared with the 50-microm-thick layer. We did not observe any advantage in using a thicker HA coating for the titanium substrates examined.
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Affiliation(s)
- M Svehla
- Orthopaedic Research Laboratories, University of New South Wales, Prince of Wales Hospital, Sydney, Australia
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53
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Nishiguchi S, Kato H, Neo M, Oka M, Kim HM, Kokubo T, Nakamura T. Alkali- and heat-treated porous titanium for orthopedic implants. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001. [PMID: 11093179 DOI: 10.1002/1097-4636(200102)54:2%3c198::aid-jbm6%3e3.0.co;2-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This study was carried out to investigate the effects of the alkali and heat treatments on the bone-bonding behavior of porous titanium implants. Porous titanium implants had a 4.6 mm solid core and a 0.7 mm thick porous outer layer using pure titanium plasma-spray technique. Three types of porous implants were prepared from these pieces: 1.control implant (CL implant) as manufactured 2.AW-glass ceramic bottom-coated implant (AW implant) in which AW-glass ceramic was coated on only the bottom of the pore of the implant 3.alkali- and heat-treated implant (AH implant), where implants were immersed in 5 mol/L NaOH solution at 60 degrees C for 24 h and subsequently heated at 600 degrees C for 1 h. The implants were inserted into bilateral femora of six dogs hemi-transcortically in a randomized manner. At 4 weeks, push-out tests revealed that the mean shear strengths of the CL, AW, and AH implants were about 10.8, 12.7, and 15.0 MPa, respectively. At 12 weeks there was no significant difference between the bonding strengths of the three types of the porous implants (16.0-16.7 MPa). Histologically and histomorphologically, direct bone contact with the implant surface was significantly higher in the AH implants than the CL and AW implants both at 4 and 12 weeks. Thus, the higher bonding strength between bone and alkali- and heat-treated titanium implants was attributed to the direct bonding between bone and titanium surface. In conclusion, alkali and heat treatments can provide porous titanium implants with earlier stable fixation.
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Affiliation(s)
- S Nishiguchi
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Shougoin-kawaharacho 54, Sakyo-ku, Kyoto 606-8507, Japan.
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54
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Nishiguchi S, Kato H, Neo M, Oka M, Kim HM, Kokubo T, Nakamura T. Alkali- and heat-treated porous titanium for orthopedic implants. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2001; 54:198-208. [PMID: 11093179 DOI: 10.1002/1097-4636(200102)54:2<198::aid-jbm6>3.0.co;2-7] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This study was carried out to investigate the effects of the alkali and heat treatments on the bone-bonding behavior of porous titanium implants. Porous titanium implants had a 4.6 mm solid core and a 0.7 mm thick porous outer layer using pure titanium plasma-spray technique. Three types of porous implants were prepared from these pieces: 1.control implant (CL implant) as manufactured 2.AW-glass ceramic bottom-coated implant (AW implant) in which AW-glass ceramic was coated on only the bottom of the pore of the implant 3.alkali- and heat-treated implant (AH implant), where implants were immersed in 5 mol/L NaOH solution at 60 degrees C for 24 h and subsequently heated at 600 degrees C for 1 h. The implants were inserted into bilateral femora of six dogs hemi-transcortically in a randomized manner. At 4 weeks, push-out tests revealed that the mean shear strengths of the CL, AW, and AH implants were about 10.8, 12.7, and 15.0 MPa, respectively. At 12 weeks there was no significant difference between the bonding strengths of the three types of the porous implants (16.0-16.7 MPa). Histologically and histomorphologically, direct bone contact with the implant surface was significantly higher in the AH implants than the CL and AW implants both at 4 and 12 weeks. Thus, the higher bonding strength between bone and alkali- and heat-treated titanium implants was attributed to the direct bonding between bone and titanium surface. In conclusion, alkali and heat treatments can provide porous titanium implants with earlier stable fixation.
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Affiliation(s)
- S Nishiguchi
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyoto University, Shougoin-kawaharacho 54, Sakyo-ku, Kyoto 606-8507, Japan.
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55
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Thian E, Loh N, Khor K, Tor S. Effects of debinding parameters on powder injection molded Ti-6Al-4V/HA composite parts. ADV POWDER TECHNOL 2001. [DOI: 10.1163/156855201750537901] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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56
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Svehla M, Morberg P, Zicat B, Bruce W, Sonnabend D, Walsh WR. Morphometric and mechanical evaluation of titanium implant integration: comparison of five surface structures. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 2000; 51:15-22. [PMID: 10813740 DOI: 10.1002/(sici)1097-4636(200007)51:1<15::aid-jbm3>3.0.co;2-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Achieving a stable bone-implant interface is an important factor in the long-term outcome of joint arthroplasty. In this study, we employed an ovine bicortical model to compare the bone-healing response to five different surfaces on titanium alloy implants: grit blasted (GB), grit blasted plus hydroxyapatite (50 microm thick) coating (GBHA), Porocoat(R) (PC), Porocoat(R) with HA (PCHA) and smooth (S). Push-out testing, histology, and backscatter scanning electron microscope (SEM) imaging were employed to assess the healing response at 4, 8, and 12 weeks. Push-out testing revealed PC and PCHA surfaces resulted in significantly greater mechanical fixation over all other implant types at all time points (p <.05). HA coating on the grit-blasted surface significantly improved fixation at 8 and 12 weeks (p <.05). The addition of HA onto the porous coating did not significantly improve fixation in this model. Quantification of ingrowth/ongrowth from SEM images revealed that HA coating of the grit-blasted surfaces resulted in significantly more ongrowth at 4 weeks (p <.05).
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Affiliation(s)
- M Svehla
- Orthopaedic Research Laboratories, Room 2-41, Level 2, South Wing, Edmund Blacket Building, Department of Surgery, Prince of Wales Hospital, University of New South Wales, 2031, Sydney, Australia
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57
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Abstract
The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation.
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Affiliation(s)
- H Kienapfel
- Department of Orthopaedic Surgery, Philipps University, Marburg, Federal Republic of Germany
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58
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Grötz KA, Wahlmann UW, Götz H, al-Nawas B, Duschner H, Wagner W. [Micromorphometry and stereography of rough depth relief coated implant surfaces by scanning electron microscopy and confocal laser scanning microscopy]. BIOMED ENG-BIOMED TE 1998; 43 Suppl:400-6. [PMID: 9859417 DOI: 10.1515/bmte.1998.43.s1.400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- K A Grötz
- Johannes Gutenberg Universität, Fachbereich Medizin, Klinik für Mund-, Kiefer- und Gesichtschirurgie, Mainz
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McFarland CD, Jenkins M, Griesser HJ, Chatelier RC, Steele JG, Underwood PA. Albumin-binding surfaces: synthesis and characterization. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 1998; 9:1207-25. [PMID: 9860181 DOI: 10.1163/156856298x00730] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The nature of the proteinaceous film deposited on a biomaterial surface following implantation is a key determinant of the subsequent biological response. To achieve selectivity in the formation of this film, monoclonal antibodies have been coupled to a range of solid substrates using avidin-biotin technology. Antibody clones varied in their antigen-binding activity following insertion of biotin groups into lysine residues. Biotinylated antibodies coupled to solid substrates via an immobilized avidin bridge retained their biological activity. During immobilization of avidin a significant proportion of the protein molecules were passively adsorbed rather than covalently attached to the surface. This loosely bound material could be removed by stringent elution procedures which resulted in a surface density of 5.4 pmol avidin cm(-2). Although these conditions would be harsh enough to denature monoclonal antibodies, they did not destroy the biotin-binding activity of the residual surface-coupled avidin, enabling the subsequent immobilization of biotinylated antibodies. The two-step immobilization technique allowed the use of gentle protein modification procedures, reduced the risk of surface-induced denaturation and removed loosely bound material from the surface. The versatility of the technique encourages its application to a wide range of immobilization systems where retention of biological activity is a key requirement.
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Affiliation(s)
- C D McFarland
- Cooperative Research Centre for Cardiac Technology, CSIRO Molecular Science, Sydney Laboratory, North Ryde, NSW, Australia
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