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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:23 |
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Conference: Bucharest University Faculty of Physics 2018 Meeting
Section: Polymer Physics
Title:
Influence of light curing protocol on structure and volumetric dimensional changes for dental resin composites
Authors:
Eduard GATIN(1)(2), Stefan-Marian IORDACHE(3), Ana-Maria IORDACHE(3)
Affiliation:
1) University of Medicine “Carol Davila”, Faculty of Medicine, Blv. Eroii Sanitari 8, Sector 5, Bucharest, Romania;
2) University of Bucharest, Faculty of Physics, Materials Department, P.O. Box MG – 11, Magurele – Bucharest, Romania;
3) University of Bucharest, 3Nano-SAE Research Centre, P.O. Box MG- 38, Magurele, Romania.
E-mail
masterdent2009@yahoo.com, stefan@3nanosae.org
Keywords:
Raman spectroscopy, dental resin composites, filler micro / nano, light curing.
Abstract:
Filler – polymer matrix coupling determines, to a large extent, the mechanical strength and clinical longevity of dental composites. Incorporation of filler into resin matrix greatly influences and improves material properties provided that filler particles are bonded to polymer matrix or otherwise it may actually weaken the resin. The dimensional stability of resin composite materials is affected by polymerization shrinkage, degree of conversion, thermal contraction and expansion, and interactions with an aqueous environment. It has been reported that the same degree of conversion is produced by a fixed amount of energy density, but we suggest to account for variations in irradiation intensity, time and working mode of the curing lamp. To our study it was used a curing LED lamp (Light emitting diodes, λ = 420 ÷ 480 nm), with different curing programs (variable light intensity, different time rates and mixed). Materials used through our investigation were two composites resins (RBC) with the same polymer matrix, but different filler (micro / nano filler). For sample properties evaluation there were used pycnometer technique (pycnometer from Paul Marienfeld Gmbh, Germany) and RAMAN spectroscopy technique (MiniRam Equipment from B&W Tek Inc, USA; 785 nm laser source). Results obtained are trying to suggest a better protocol for light curing process, for improved mechanical properties and biocompatibility of the dental resin based composites (RBC).
References:
1. Kramer N., Lochbauer U., Garcia – Godoy F., Frankerberger R. (2008). Light curing of resin-based composites in the LED era. Am J Dent, 21 (3), 135 – 142.
2. Chutinan S., Platt J.A., Cochran M.A., Moore B.K. (2004). Volumetric dimensional change of six direct core materials. Dent Mater, 20 (4), 345 – 351.
3. Larkin P., Infrared and Raman Spectroscopy; Principles and Spectral Interpretation, Elsevier Publishing House 2011.
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