| 1. |
- Anders, Halldin, et al.
(författare)
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Improved osseointegration and interlocking capacity with dual acid treated implants: a rabbit study.
- 2016
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Ingår i: Clinical Oral Implants Research. - : Wiley. - 0905-7161 .- 1600-0501. ; 27, s. 22-30
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Tidskriftsartikel (refereegranskat)abstract
- Aim To investigate how osseointegration is affected by different nano- and microstructures. The hypothesis was that the surface structure created by dual acid treatment (AT-1), applied on a reduced topography, might achieve equivalent biomechanical performance as a rougher surface treated with hydrofluoric acid (HF). Materials and methods In a preclinical rabbit study, three groups (I, II, and III) comprised of test and control implants were inserted in 30 rabbits. The microstructures of the test implants were either produced by blasting with coarse (I) or fine (II) titanium particles or remained turned (III). All test implants were thereafter treated with AT-1 resulting in three different test surfaces. The microstructure of the control implants was produced by blasting with coarse titanium particles thereafter treated with HF. The surface topography was characterized by interferometry. Biomechanical (removal torque) and histomorphometric (bone–implant contact; bone area) performances were measured after 4 or 12 weeks of healing. Results Removal torque measurement demonstrated that test implants in group I had an enhanced biomechanical performance compared to that of the control despite similar surface roughness value (Sa). At 4 weeks of healing, group II test implants showed equivalent biomechanical performance to that of the control, despite a decreased Sa value. Group III test implants showed decreased biomechanical performance to that of the control. Conclusions: The results of the present study suggest that nano- and microstructure alteration by AT-1 on a blasted implant might enhance the initial biomechanical performance, while for longer healing time, the surface interlocking capacity seems to be more important.
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| 2. |
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| 3. |
- Mattisson, I., et al.
(författare)
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Surface characterization, electrochemical properties and in vitro testing of hierarchically structured titanium surfaces
- 2013
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Ingår i: Materials Research Bulletin. - : Elsevier BV. - 0025-5408. ; 48:2, s. 389-398
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Tidskriftsartikel (refereegranskat)abstract
- Newly designed implant surfaces with hierarchic structure have been characterized with respect to chemical composition, topography, electrical properties and cell culturing. Three levels of surface roughness are induced starting from a blasted surface with the naturally formed oxide layer. Dissolution of the blasted surface is obtained by chemical treatment in oxalic acid. The surface becomes smoother with multitude of shallow depressions in the walls and bottoms of the blasted structure. The surface oxide layer formed is somewhat thicker than the naturally formed oxide and may contain oxalate. In the final step, part of the oxide layer is dissolved in hydrofluoric acid leading to a high concentration of soluble titanium species. A nanostructured surface is formed by precipitation of titanium oxide at spots on the surface where locally the pH is increased due to hydrogen evolution. The surface roughness is only marginally changed by the chemical treatment while the conductivity of the surface layer is lower for the chemically treated surfaces compared with the blasted reference. The hierarchical structure mimics many natural processes for achieving high shear strength. © 2012 Elsevier Ltd.
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| 5. |
- Suska, F., et al.
(författare)
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IL-1a, IL-1ß and TNF-a secretion during in vivo/ex vivo cellular interactions with titanium and copper
- 2003
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Ingår i: Biomaterials. - 0142-9612 .- 1878-5905. ; 24:3, s. 461-468
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Tidskriftsartikel (refereegranskat)abstract
- Titanium (Ti) and copper (Cu) were used to evaluate cytokine secretion around materials with different chemical properties. Ti disks were coated with Cu or left uncoated. The disks were inserted subcutaneously in rats for 1, 3, 12, 18, 24 and 48h. Interleukin-1a (IL-1a), IL-1ß and tumor necrosis factor-a (TNF-a) concentrations were measured in vivo around the materials, in sham operated sites, and after ex vivo incubation of surface adherent cells. Ti and Cu revealed distinct cytokine expression patterns. Cu recruited cells showed higher and prolonged release of IL-1a than Ti at longer times (>24h), whereas Ti exhibited a transient IL-1a response at earlier periods (<24h). An early enhanced secretion of TNF-a characterized Ti. Low amounts of IL-1ß were found around both materials. Sham site recruited cells produced lower levels of cytokines. The results after ex vivo incubations were similar to those in vivo. This study shows that material chemical properties influence early cytokine production. The Ti-associated transient rise of IL-1a and TNF-a may be of importance for the early tissue response around biocompatible materials, while a delayed high IL-1a expression could be a marker of inflammation induced by toxic materials. © 2002 Elsevier Science Ltd. All rights reserved.
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| 6. |
- Tengvall, Pentti, et al.
(författare)
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Preparation of multilayer plasma protein films on silicon by EDC/NHS coupling chemistry
- 2003
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Ingår i: Colloids and Surfaces B. - 0927-7765 .- 1873-4367. ; 28:4, s. 261-272
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Tidskriftsartikel (refereegranskat)abstract
- Crosslinked multilayer protein films were prepared from fibrinogen, albumin, IgG, a combination of fibrinogen and catalase, and blood plasma on silicon by ethyl-dimethyl-aminopropylcarbodiimide and N-hydroxy-succinimide coupling chemistry. The 4-70 nm thick films were placed in blood plasma and the additional protein deposition measured by null ellipsometry after 5 or 60 min of incubation. The activation of the complement system and intrinsic pathway of coagulation were indicated through the subsequent binding of anti-C3c, anti-C3d, anti-properdin and anti-HMWK on top of the surface bound blood plasma. The proportion of Annexin V, Propidium Iodide and 4,6-diamidino-2-phenylindole positive cells, and the secretion of tumor necrosis factor a (TNF-a) and interleukin-10 (IL-10) were analysed in a monocyte culture. The results show that well known protein coupling techniques can be used for the preparation of protein layers with well controlled thickness. The layers possess low contact activation of blood plasma and induce different release of TNF-a and IL-10 in monocyte cultures. © 2002 Elsevier Science B.V. All rights reserved.
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