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Document Type: Artigo
Title: Effect of immediate or delayed light-activation on curing kinetics and shrinkage stress of dual-cure resin cements
Authors: Silva, André Luís Faria e
Martins, Luis Roberto Marcondes
Boaro, Letícia Cristina Cidreira
Braga, Roberto R.
Arias, Vanessa Gallego
Piva, Evandro Lima
Issue Date: 2011
Abstract: Objectives: This study evaluated the effect of light activation (absence, immediate, or delayed) on conversion kinetics and polymerization stress of three commercial dual-cured resin cements (Enforce, RelyX ARC, and Panavia F). Methods: Degree of conversion (DC) was monitored for 30 minutes using real-time near Fourier transform infrared spectroscopy. The cement was mixed, placed on the spectrometer sample holder, and light activated either immediately or after five minutes (delayed light activation). When no light activation was performed, the materials were protected from light exposure (control). DC was evaluated at five and 30 minutes postmixture. Maximum rates of polymerization (Rpmax) were obtained from the first derivative of the DC vs time curve. Polymerization stress was monitored for 30 minutes in 1-mm-thick specimens inserted between two cylinders attached to a universal testing machine. Data were submitted to analysis of variance/Tukey tests (a¼0.05). Results: Immediate light activation promoted the highest DC at five minutes. At 30 minutes, only RelyX ARC did not present a significant difference in DC between activation modes. Enforce and Panavia F presented higher Rpmax for immediate and delayed light-activation, respectively. RelyX ARC showed similar Rpmax for all activation modes. The absence of light activation resulted in the lowest stress followed by delayed light activation, while immediate light activation led to the highest values. RelyX ARC showed higher stress than Enforce, while the stress of Panavia F was similar to that of the others. Conclusion: Delayed light activation reduced the polymerization stress of the resin cements tested without jeopardizing DC.
Keywords: Cinética de conversão
Tensão de polimerização
Grau de conversão (DC)
Taxas de polimerização (RPMAX)
ISSN: 1559-2863
Publisher / Institution : Academy of Operative Dentistry
Citation: FARIA E SILVA, A. L. F. et al. Effect of immediate or delayed light-activation on curing kinetics and shrinkage stress of dual-cure resin cements. Operative Dentistry, Los Angeles, v. 36, n. 2, p. 196-204, 2011. Disponível em: <>. Acesso em: 28 ago. 2014.
License: Autorização para publicação no Repositório Institucional da Universidade Federal de Sergipe (RIUFS) concedida pelo editor
Appears in Collections:DOD - Artigos de periódicos

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