title: Conversion degrees of resin composites using different light sources.
abstract: OBJECTIVE
  The objective of this study was to compare the conversion degree of six different composite materials (Filtek Z 250, Filtek P60, Spectrum TPH, Pertac II, Clearfil AP-X, and Clearfil Photo Posterior) using three different light sources (blue light-emitting diode [LED], plasma arc curing [PAC], and conventional halogen lamp [QTH]).
  
  
  METHODS
  Composites were placed in a 2 mm thick and 5 mm diameter Teflon molds and light cured from the top using three methods: LED for 40 s, PAC for 10 s, and QTH for 40 s. A Fourier Transform Infrared Spectroscopy (FTIR) was used to evaluate the degree of conversion (DC) (n=5). The results were analyzed with two-way analysis of variance and Tukey HSD test.
  
  
  RESULTS
  DC was significantly influenced by two variables, light source and composite (P<.05). QTH revealed significantly higher DC values than LED (P<.05). However, there were no significant differences between DC values of QTH and PAC or between DC values of LED and PAC (P>.05). The highest DC was observed in the Z 250 composite specimens following photopolymerization with QTH (70%). The lowest DC was observed in Clearfil Photo Posterior composite specimens following photo-polymerization with LED (43%).
  
  
  CONCLUSIONS
  The DC was found to be changing according to both light sources and composite materials used. Conventional light halogen (QTH) from light sources and Filtek Z 250 and Filtek P 60 among composite materials showed the most DC performance.
authors: Department of Restorative Dentistry, Faculty of Dentistry, Selcuk University, Konya, TURKIYE.
authors: Bora
authors: B
authors: Ozturk
authors: Nevin
authors: N
authors: Cobanoglu
authors: Ali Rıza
authors: AR
authors: Cetin
authors: Beniz
authors: B
authors: Gunduz
keywords: Degree of conversion; FTIR; composites; light sources; monomer