title: Effects of plasma-emulating light emitting diode (LED) versus conventional LED on cytotoxic effects of orthodontic cements as a function of polymerization capacity.
abstract: OBJECTIVE
  The study was aimed at evaluating, in vitro, cytotoxicity of four resin-based orthodontic cements (RBOC) as a function of degree of conversion (DC) and the light curing unit (LCU) employed on mouse fibroblast (L929).
  
  
  METHODS
  Nine samples were manufactured for each group of cements using plasma-emulating light-emitting diode (LED) and conventional LED. Toxicity was assessed by immersing four specimens to culture medium (24 h/37°C) for extracting residual monomer or cytotoxic substance. Cell mitochondrial activity of L929 cell was evaluated using methyl tetrazolium (MTT) test. DC was evaluated by Fourier transform infrared spectroscopy for five samples.
  
  
  RESULTS
  Cements, LCUs, and interaction between cements and LCUs were found to play a statistically significant role in cytotoxicity (p < 0.0001). Opal band cement (OPAL) plasma LED was found noncytotoxic (90-100% cell viability). The other RBOC-LCU combinations were slightly cytotoxic (60-90% cell viability). Cements (p < 0.01) and LCUs (p < 0.05) had a statistically significant effect on DC. Conversely, interaction between cement and LCU had no statistically significant role on DC (p > 0.05). OPAL plasma LED displayed the highest levels of DC. The correlations between cell viability and DC were positive for three RBOCs.
  
  
  CONCLUSIONS
  Therefore, high-intensity LCUs can be said to efficiently affect polymerization, so higher DC rates may achieve higher cell viability rates.
  
  
  CONCLUSIONS
  Cements and LCUs must be matched to each another to result in higher DC and maximal biocompatibility. Dual cure systems presented relatively high cell survival and higher DC, thus expressing superior to single-cure systems with plasma LED.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey bayramcorekci@yahoo.com.
authors.forename: B
authors.initials: B
authors.lastname: Çörekçi
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
authors.forename: K
authors.initials: K
authors.lastname: Halıcıoğlu
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
authors.forename: C
authors.initials: C
authors.lastname: Irgın
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
authors.forename: Y
authors.initials: Y
authors.lastname: Hezenci
authors.affiliation: Department of Medical Pharmacology, Faculty of Medicine, Abant İzzet Baysal University, Bolu, Turkey.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Yavuz
mesh_terms: D000180:Acrylic Resins / Q000528:radiation effects / Q000633:toxicity; D000538:Aluminum Silicates / Q000528:radiation effects / Q000633:toxicity; D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D055117:Curing Lights, Dental / Q000009:adverse effects*; D003738:Dental Cements / Q000528:radiation effects / Q000633:toxicity*; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology; D055115:Light-Curing of Dental Adhesives / Q000009:adverse effects* / Q000295:instrumentation; D051379:Mice; D008928:Mitochondria / Q000187:drug effects / Q000473:pathology; D058105:Polymerization; D019279:Resin Cements / Q000528:radiation effects / Q000633:toxicity; D018570:Risk Assessment; D013997:Time Factors; D018675:Toxicity Tests
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D003738:Dental Cements; C112133:Fuji Ortho; D019279:Resin Cements
keywords: Cytotoxicity; cements; degree of conversion; mouse fibroblast