title: A Fourier transform Raman spectroscopy analysis of the degree of conversion of a universal hybrid resin composite cured with light-emitting diode curing units.
abstract: The degree of conversion (DC), of a universal hybrid resin composite cured with LED curing units with low and high power densities and a 510 mW/cm2 quartz tungsten halogen unit, was investigated with Fourier Transform Raman spectroscopy. Three curing depths (0, 2, 4mm) and 0 and 7 mm light guide tip - resin composite (LT - RC) distances were tested. The DC of the LED units varied between 52.3% - 59.8% at the top surface and 46.4% - 57.0% at 4 mm depth. The DC of specimen cured with a 0 mm LT- RC distance at 4 mm depth varied between 50.8% - 57.0% and with 7 mm distance between 46.4% - 55.4%. The low power density LED unit showed a significantly lower DC for both distances at all depth levels compared to the other curing units (p < 0.05). Significant differences between the other curing units were only found at the 4 mm depth level cured from 7 mm distance (p < 0.05). The reduction in DC by increasing LT- RC distance was less than 10% for all curing units. It can be concluded that the improved LED curing units could cure the studied resin composite to the same DC as the control unit.
authors.affiliation: Public Dental Health Clinic, Seminariegatan, Skellefteå, Sweden. anders.lindberg@odont.umu.se
authors.forename: Anders
authors.initials: A
authors.lastname: Lindberg
authors.forename: Nazanin
authors.initials: N
authors.lastname: Emami
authors.forename: Jan W V
authors.initials: JW
authors.lastname: van Dijken
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D008422:Materials Testing; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*
chemical_list: D003188:Composite Resins