Influence of the photoinitiator system and light photoactivation units on the degree of conversion of dental composites

• Main Authors: Isabel Cristina Celerino de Moraes Porto, Luis Eduardo Silva Soares, Airton Abrahão Martin, Vanessa Cavalli, Priscila Christiane Suzy Liporoni
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Pesquisa Odontológica 2010-12-01
• Series: Brazilian Oral Research
• Subjects: Composite Resins; Dental Equipment; Curing Lights
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-83242010000400017

The aim of this study was to observe the influence of two light polymerization units (LED or halogen light) on the degree of conversion (DC) of three dental composites with lighter shades and a different photoinitiator system. The top (T) and bottom (B) surfaces of 60 discs of composite resin (Filtek™ Supreme, Filtek™ Z250, Tetric™ Ceram Bleach) cured either by LED or by halogen lamp (HL) were studied using an FT-Raman spectrometer. The degree of conversion (DC) was evaluated by following the changes in the intensity of the methacrylate C=C stretching mode at 1640 cm-1. The calculated DC ranged from 54.2% (B) to 73.4% (T) and from 60.2% (B) to 76.6% (T) for the LED and HL, respectively. LED and halogen devices were able to produce an adequate DC for all the resins tested.