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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 17:44 |
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Conference: Bucharest University Faculty of Physics 2002 Meeting
Section: Electricity and Biophysics: Honorary Session Dedicated to Professors: Victor Gheorghe (Head of the Dept. 1972-1984) and Grigore Turcu
Title:
Qualitative PIXE analysis of mineral elements in some dental composites
Authors:
E.A. Preoteasa, Andreea Iordan, Maria Moldovan*, Livia Harangus, C. Ciortea, M. Gugiu
Affiliation:
Horia Hulubei Institute for Physics and Nuclear Engineering, P.O.B. MG-6, Bucharest
*Raluca Ripan Institute of Chemistry, Cluj-Napoca
E-mail
Keywords:
Abstract:
Dental composites, made by particles of glass, ceramics and quartz embedded in an organic polymer, develop at a high
rate. However, commercial composites are expensive and recently, the Romanian biomaterials “Restacril” were prepared to offer a low-cost alternative. The durability of dental fillings depends not only on biomaterial’s gross chemical composition, but also on impurities. These may influence the chemical, mechanical and surface properties of the inorganic particles and modify the composites’ clinical behavior. Thus elemental analysis is necessary to improve the biomaterials’ quality. Nuclear and atomic methods allow sensitive multielement detection, and we previously analyzed some commercial composites by particle-induced X-ray emission (PIXE) [1]. Here we applied PIXE in the qualitative analysis of six new Romanian biomaterials, aiming to compare their nominal and detected composition and paying attention to the impurities. The PIXE measurements were performed with 3 MeV protons at the 8.5 MV NIPNE-HH tandem accelerator, using a hyper pure Ge detector, normal to the beam and connected to a multichannel analyzer and to a computer. Solid samples of composites with a flat surface were fixed at 45o, absorber foil of Al 30 mm thick was used, and integration of beam current was done. In all composites PIXE detected mineral elements with Z > 19 down to trace levels. All major nominal elements with Z > 20 - Ca, Sr, Zr, Ba, and Yb - were detected by PIXE. In addition, many minor and trace elements absent from the nominal formulations were seen, including K, Ti, Mn, Fe, Ni, Cu, Zn, Ga, Ag, Cd, Hf, and As/Pb. Such impurities may come from rough materials and preparative technologies. The impurities in Romanian composites are comparable to those in some commercial biomaterials but higher than in other ones. Thus PIXE analysis of mineral elements in Romanian composites, even qualitative, appears useful for quality control and improvement.
1. E.A. Preoteasa, C. Ciortea, B. Constantinescu, D. Fluerasu, S.E. Enescu, D. Pantelica, F. Negoita, E. Preoteasa, Nucl. Inst. and Meth. B, 189, 426, 2002.
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