title: Degree of conversion of adhesive systems light-cured by LED and halogen light.
abstract: This study evaluated the effect of blue light emitting diode (LED) and quartz tungsten halogen (QTH) on the degree of conversion (DC) of an etch-and-rinse Single Bond adhesive system (SB) and a mixture composed of primer solution and resin bond from Clearfil SE Bond self-etching adhesive system (CB) using Fourier transform infrared analysis (FTIR). Adhesives were applied to potassium bromide pellet surfaces and FTIR analyses were performed before and after photo-activation for 10 s with either LED (Freelight 1 - 400 mw/cm(2)) or QTH (XL 3000 - 630 mw/cm(2)) light-curing units (n=8). Additional FTIR spectra were obtained from photo-activated samples stored in distilled water for 1 week. The DC was calculated by comparing the spectra obtained from adhesive resins before and after photo-activation. The results were analyzed by two-way split-plot ANOVA and Tukey's test (p<0.05). Both adhesive systems exhibited low DC (%) immediately after photo-activation (SB/QTH: 18.7 +/- 3.9; SB/LED: 13.5 +/- 3.3; CF/QTH: 13.6 +/- 1.9; CF/LED: 6.1 +/- 1.0). The DC of samples light-cured with LED was lower than DC of those light-cured with QTH, immediately after light curing and after 1 week (SB/QTH: 51.3 +/- 6.6; SB/LED: 50.3 +/- 4.8; CF/QTH: 56.5 +/- 2.9; CF/LED: 49.2 +/- 4.9). The LED curing unit used to photo-activate the adhesive resins promoted lower DC than the QTH curing unit both immediately after light curing and 1 week after storage in water.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Cesar Augusto Galvão
authors.initials: CA
authors.lastname: Arrais
authors.forename: Fenelon Martinho
authors.initials: FM
authors.lastname: Pontes
authors.forename: Luis Presley Serejo Dos
authors.initials: LP
authors.lastname: Santos
authors.forename: Edson Roberto
authors.initials: ER
authors.lastname: Leite
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
mesh_terms: D000269:Adhesives / Q000737:chemistry / Q000528:radiation effects*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry / Q000528:radiation effects*; D006219:Halogens / Q000008:administration & dosage; D008027:Light; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods
chemical_list: D000269:Adhesives; C438313:Clearfil SE Bond; D006219:Halogens; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate