Calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. Deproteinized xenografts are primarily constituted of natural apatites, sintered or not. Variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. The purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, Bio-Oss (Geistlich Biomaterials, Wolhuser, Switzerland) and Gen-Ox (Baumer S.A., Brazil), widely used as bone grafts. Scanning electron microscopy, infrared region spectroscopy, X-ray diffraction, thermogravimetry and degradation analysis were conducted. The results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. Bio-Oss presented greater dissolution in Tris-HCl than Gen-Ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. In conclusion, both commercial materials are hydroxyapatite compounds, Bio-Oss being less crystalline than Gen-Ox and, therefore, more prone to degradation.
Cell-titanium interactions are crucial to the clinical success of bone and dental implants. The physico-chemical characteristics of the substrates surface influence osteoblast proliferation, differentiation, and activity as well. The osteoblast behavior was analyzed on three different titanium surfaces: ground with an abrasive 600 grit SiC paper, blasted with alumina particles (65 microm diameter) and alumina blasted followed by a double chemical etch (4% HF+4% HF/8% H2O2). Scanning electron microscopy (SEM) and profilometry showed distinct microtopographies. Ground samples showed parallel-groove orientation. The Al2O3-blasted surface presented the roughest microtopography with aluminum-rich particles incrusted in the titanium surface. Osteoblasts cells from femora of Balb/c mice were seeded onto the substrates tested. Cell morphology and initial attachment were evaluated by SEM. Osteoblasts adhered to and spread on all samples tested. However, on rough surfaces, osteoblasts did not spread completely and acquired a polygonal morphology. Besides, the cell proliferation rate was diminished at the beginning of incubation on rough surfaces. Our results suggest a delay, rather than an impairment, in osteoblast viability and alkaline phosphatase activity when cells are cultured on rough surfaces, inducing a distinct osteoblast phenotype, rather than blocking its activity. At least in the culture conditions used in this work, alumina particles did not affect osteoblast behavior.
Polyvinyl alcohol (PVA) hydrogels are materials for potential use in burn healing. Silver nanoparticles can be synthesized within PVA hydrogels giving antimicrobial hydrogels. Hydrogels have to be swollen prior to their application, and the common medium available for that in hospitals is saline solution, but the hydrogel could also take up some of the wound's fluid. This work developed gamma-irradiated PVA/nano-Ag hydrogels for potential use in burn dressing applications. Silver nitrate (AgNO 3 ) was used as nano-Ag precursor agent. Saline solution, phosphate-buffered solution (PBS) pH 7.4 and solution pH 4.0 were used as swelling media. Microstructural evaluation revealed an effect of the nanoparticles on PVA crystallization. The swelling of the PVA-Ag samples in solution pH 4.0 was low, as was their silver delivery, compared with the equivalent samples swollen in the other media. The highest swelling and silver delivery were related to samples prepared with 0.50% AgNO 3 , and they also presented lower strength in PBS pH 7.4 and solution pH 4.0. Both PVA-Ag samples were also non-toxic and presented antimicrobial activity, confirming that 0.25% AgNO 3 concentration is sufficient to establish an antimicrobial effect. Both PVA-Ag samples presented suitable mechanical and swelling properties in all media, representative of potential burn site conditions.
he aim of this work was to characterize six hydroxyapatites in granular form for applications in medicine and dentistry as bone graft and to compare with manufacturers´ specification. These samples were produced by four different manufacturers, and all of them are easily available in the Brazilian market. Physicochemical characterization was carried out by using electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and surface area (BET) measurements. The results show that just one hydroxyapatite sample exhibited characterisitics in perfect agreement with the manufacturers' specifications. The studied parameters, namely crystallinity, surface area and composition may be used to estimate hydroxyapatite's biodegradability and as a criterion for quality control. Uniterms: Hydroxyapatite; Calcium phosphate; Bone graft; Physicochemical characterization. objetivo desse trabalho foi caracterizar seis hidroxiapatitas granulares para aplicação em área médico-odontológica como material de enxerto. Estes materiais foram produzidos por quatro diferentes fabricantes e são todos facilmente disponíveis no mercado brasileiro. A caracterização físico-química foi realizada por meio de microscopia eletrônica de varredura, difração de raios-X, espectroscopia de infravermelho e área superficial específica (BET). Os resultados mostraram que apenas um dos produtos teve a caracterização perfeitamente de acordo com a especificação do fabricante. Os parâmetros de cristalinidade, área superficial e composição podem ser usados para estimar a biodegradabilidade da hidroxiapatita e como critério de controle de qualidade desses materiais. Unitermos: Hidroxiapatita; Fosfato de cálcio; Enxerto ósseo; Caracterização físico-química.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.