Photoinitiation chemistry affects light transmission and degree of conversion of curing experimental dental resin composites
In: Dental Materials, Jg. 23 (2007-07-01), S. 807-813
Online
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Zugriff:
Introduction The effect of photoinitiator and co-initiator chemistry on the setting reaction and degree of conversion of dental resin-based composites (RBCs) has rarely been determined explicitly. This work examines the effect of type and concentration of photoinitiator and co-initiator on the rate of change of light transmission throughout polymerisation and degree of conversion of model RBC formulations. Methods Bisphenol-A diglycidyl ether dimethacrylate (bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) (6:4 molar ratio) resins filled with silanized glass filler (74 wt.%) and containing various photoinitiators (camphorquinone; CQ, 1-phenyl-1,2-propanedione; PPD, benzil; BZ), co-initiator types ( N , N -dimethyl- p -amino benzoic acid ethyl ester; DABE, N , N -cyanoethyl methylaniline; CEMA, N , N -diethanol- p -toluidine; DEPT) and concentration (0.0–0.3% DABE) were polymerised using a halogen or LED light curing-unit (LCU) for 10, 20 and 40 s. The setting reaction was monitored in real-time by measuring the light transmittance through the curing specimen and bulk degree of conversion (DC) evaluated using Fourier transform infra-red spectroscopy. Results Specimens containing CQ and PPD cured with the halogen LCU did not have a significant effect on DC or changes in light transmission, although a significant increase in DC was observed for CQ compared with PPD specimens cured with the LED LCU. DABE and CEMA were more effective co-initiators than DEPT. Although DC was not limited by co-initiator concentration, the absence of a co-initiator resulted in marked differences in light transmission and decreased DC throughout 40 s irradiation with each LCU type. Conclusions The spectral range emitted from different types of LCU and absorption characteristics of the photoinitiator chemistry of light-activated resin-based composites play a critical role in the efficiency of polymerisation.
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Photoinitiation chemistry affects light transmission and degree of conversion of curing experimental dental resin composites
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Autor/in / Beteiligte Person: | Shortall, Adrian C. ; Palin, William M. ; Ogunyinka, A. ; Marquis, Peter M. |
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Zeitschrift: | Dental Materials, Jg. 23 (2007-07-01), S. 807-813 |
Veröffentlichung: | Elsevier BV, 2007 |
Medientyp: | unknown |
ISSN: | 0109-5641 (print) |
DOI: | 10.1016/j.dental.2006.06.016 |
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