Preparation of an experimental glass-ionomer cements and evaluation of their properties
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Preparation of an experimental glass-ionomer cements and evaluation of their properties Fatemeh Mirghaderi • Ahmad Monshi Masoud Kasiri
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Received: 21 October 2012 / Accepted: 2 November 2012 Ó Springer Science+Business Media Dordrecht 2012
Abstract The preparation of glass-ionomer cements based on the composition of SiO2–Al2O3–CaO–SrO–F and evaluation of their properties is described. Cements were prepared via the sol–gel method and characterized by XRD, BET, SEM, and EDAX analysis. The effect of various concentrations of Sr on in vitro bioactivity of the glass speciments was investigated. In vitro bioactivity of the samples was evaluated by soaking them in simulated body fluid followed by structural characterization using SEM and atomic absorption analysis. A glass specimen with 0.5 mol of Sr exhibited appropriate bioactivity. Keywords Glass-ionomer cement Strontium Bioactivity Compressive strength (CS) Simulated body fluid EDAX analysis
Introduction After the invention of glass-ionomer cements (GICs) by Wilson and Kent in the early 1970s [1–3], the preparations of these materials have been of considerable interest because of their use as a dental restorative material [4–6], and due to their unique properties such as coherency to tooth structure and base metals [7, 8], biological compatibility, and low cyto-toxicity [7, 8]. GICs have low coefficients of thermal expansion similar to that of tooth structures, which causes good thermal compatibility with tooth enamel and dentin [9]. When fluoride is released to GICs, they show anti-cariogenic properties [10]. In addition, they minimize micro-leakage at the tooth–enamel interface due to low shrinkage [11, 12]. Because of their wide range of applications especially in dentistry, significant improvements have been F. Mirghaderi (&) A. Monshi M. Kasiri Faculty of Material Science & Engineering, Najafabad Branch, Islamic Azad University, P. O. Box 85141-43131, Najafabad, Iran e-mail: [email protected]
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made since the invention of GICs, and further improvements are required in order to increase their physical properties. Historically, two common procedures have been developed for the preparation of GICs [13–26]. The main composition of the glass first studied by Wilson and Kent [1–3] was calcium-fluoro-alumino-silicate which was prepared via a conventional fusion method at high temperatures (ranging from 1,100 to 1,550 °C). This method has some problems such as uncontrolled fluorine losses during melting which causes the prepared glass to have a variable composition [1–3]. This problem can be surmounted by the use of chemical methods such as the sol–gel process which is more advantageous due to composition control and chemical homogeneity. In recent times, new formulations of glass have been developed for use as cement formers, also using the sol–gel technique. In this context, the objective of this paper is the preparation and evaluation of the properties of GICs containing strontium.
Experimental Reagents and inst
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