Effect of U3O8 Specific Surface Area on In Vitro Dissolution, Biokinetics, and Dose Coefficients

Much research has been devoted to the study of etched enamel, since it is critical to bonding. Currently, there are no precise data regarding the etched-enamel specific surface area. The aim of this study was to characterize, by two different methods, the surface of human dental enamel in vitro after being etched. It was hypothesized that differences would be observed between specimens in terms of specific surface area and grade of etching. Sixteen third molar enamel samples were etched for 30 sec with 37% phosphoric acid prior to being viewed by SEM. Etched enamel surfaces were graded according to the Galil and Wright classification. The total surface area of etched samples was determined by the BET gas absorption method. A substantial variability in total surface area was observed between and among samples. A Pearson’s Correlation Coefficient showed a lack of relationship between etch pattern and total surface area.

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Physicochemical and Biological Characterization of Ti6Al4V Particles Obtained by Implantoplasty: An In Vitro Study. Part I

Materials ◽

10.3390/ma14216507 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6507

Author(s):

Jorge Toledano-Serrabona ◽

Francisco Javier Gil ◽

Octavi Camps-Font ◽

Eduard Valmaseda-Castellón ◽

Cosme Gay-Escoda ◽

...

Keyword(s):

Cell Viability ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

In Vitro Study ◽

Vitro Study ◽

Equivalent Diameter ◽

Metal Debris ◽

Aluminum Ions

Implantoplasty is a mechanical decontamination technique that consists of polishing the supra-osseous component of the dental implant with peri-implantitis. This technique releases metal particles in the form of metal swarf and dust into the peri-implant environment. In the present in vitro study, the following physicochemical characterization tests were carried out: specific surface area, granulometry, contact angle, crystalline structure, morphology, and ion release. Besides, cytotoxicity was in turn evaluated by determining the fibroblastic and osteoblastic cell viability. As a result, the metal debris obtained by implantoplasty presented an equivalent diameter value of 159 µm (range 6–1850 µm) and a specific surface area of 0.3 m2/g on average. The particle had a plate-like shape of different sizes. The release of vanadium ions in Hank’s solution at 37 °C showed no signs of stabilization and was greater than that of titanium and aluminum ions, which means that the alloy suffers from a degradation. The particles exhibited cytotoxic effects upon human osteoblastic and fibroblastic cells in the whole extract. In conclusion, metal debris released by implantoplasty showed different sizes, surface structures and shapes. Vanadium ion levels were higher than that those of the other metal ions, and cell viability assays showed that these particles produce a significant loss of cytocompatibility on osteoblasts and fibroblasts, which means that the main cells of the peri-implant tissues might be injured.

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Mesoporous Iron(III)-Doped Hydroxyapatite Nanopowders Obtained via Iron Oxalate

Nanomaterials ◽

10.3390/nano11030811 ◽

2021 ◽

Vol 11 (3) ◽

pp. 811

Author(s):

Margarita A. Goldberg ◽

Marat R. Gafurov ◽

Fadis F. Murzakhanov ◽

Alexander S. Fomin ◽

Olga S. Antonova ◽

...

Keyword(s):

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Density Functional ◽

Covalent Bond ◽

In Vitro Tests ◽

Crystalline Region ◽

Fe Oxides ◽

Iron Oxalate

Mesoporous hydroxyapatite (HA) and iron(III)-doped HA (Fe-HA) are attractive materials for biomedical, catalytic, and environmental applications. In the present study, the nanopowders of HA and Fe-HA with a specific surface area up to 194.5 m2/g were synthesized by a simple precipitation route using iron oxalate as a source of Fe3+ cations. The influence of Fe3+ amount on the phase composition, powders morphology, Brunauer–Emmett–Teller (BET) specific surface area (S), and pore size distribution were investigated, as well as electron paramagnetic resonance and Mössbauer spectroscopy analysis were performed. According to obtained data, the Fe3+ ions were incorporated in the HA lattice, and also amorphous Fe oxides were formed contributed to the gradual increase in the S and pore volume of the powders. The Density Functional Theory calculations supported these findings and revealed Fe3+ inclusion in the crystalline region with the hybridization among Fe-3d and O-2p orbitals and a partly covalent bond formation, whilst the inclusion of Fe oxides assumed crystallinity damage and rather occurred in amorphous regions of HA nanomaterial. In vitro tests based on the MG-63 cell line demonstrated that the introduction of Fe3+ does not cause cytotoxicity and led to the enhanced cytocompatibility of HA.

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