| 1. |
- Sandin, Karin, et al.
(författare)
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The observation of nano-crystalline calcium phosphate precipitate in a simple supersaturated inorganic blood serum model - composition and morphology
- 2009
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Ingår i: Journal of Applied Biomaterials and Biomechanics. - 1722-6899 .- 1724-6024. ; 7:1, s. 13-22
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Tidskriftsartikel (refereegranskat)abstract
- Aim. Calcium phosphate deposition in blood vessels is correlated to increased mortality risk. In this study, the formation of solid calcium phosphate in an in vitro solution mimicking the inorganic part of blood serum was studied. Methods. The precipitates formed were analyzed using several experimental techniques, including infrared spectroscopy, Raman spectroscopy, X-ray energy dispersive spectroscopy, chemical analysis of combustion gases, thermogravimetric analysis, as well as transmission electron microscopy and scanning electron microscopy. Results. The results indicate a microscopically amorphous but nano-crystalline material with an overall apatite structure. A plausible stoichiometry was determined to Ca-5(PO4)(3)(HCO3)center dot 4H(2)O with an estimated solubility constant of 6.10(-39) (mol/L)(9). Bicarbonate in the water solution was shown to be essential for the precipitation, giving implications for in vitro studies. Conclusions. The calcium phosphate formed in this study shows many similarities to pathological calcium phosphates regarding composition, morphology and crystallinity.
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| 2. |
- Sul, Young-Taeg, 1960, et al.
(författare)
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Bone tissue responses to Mg-incorporated oxidized implants and machine-turned implants in the rabbit femur
- 2005
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Ingår i: Journal of Applied Biomaterials & Biomechanics 2005. - 1724-6024. ; 3:1, s. 18-28
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies have demonstrated a significant improvement in the bone response to oxidized titanium implants. Little is known about the effects of specific oxide properties on the bone tissue responses to titanium implants. This study in-vestigated the bone tissue responses to magnesium (Mg)-incorporated oxidized titanium implants and machine-turned titani-um implants in the rabbit femur. The oxidized implants were prepared using micro arc oxidation (MAO) methods. Surface oxide properties were characterized by using various surface analytic techniques, involving scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS) and optical interferometry. Screw shaped titanium implants, 10 machine-turned implants (controls) and 10 Mg-incorporated im-plants (tests) were inserted in the femoral condyles of 10 New Zealand white rabbits. After a 6-week healing period, resonance frequency analyses and removal torque measurements of the Mg-incorporated oxidized implants demonstrated significant im-provements in implant integration with bone in comparison to machine-turned implants, p=0.007 and p=0.017, respectively. Bone growth in the pores of the oxidized implants was probably incomplete at a follow-up of 6 weeks, as indicated by SEM and EDS measurements. Mg-incorporated titanium implants significantly improved bone responses as compared with machine-turned control implants. Considering the differences and similarities of the surface oxide properties of controls and test im-plants, the enhanced bone responses to Mg-incorporated implants could be explained by the Mg surface chemistry of the test im-plants. (Journal of Applied Biomaterials & Biomechanics 2005; 3: 18-28)
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