Effects of plasma-emulating light-emitting diode (LED) versus conventional LED on cytotoxic effects and polymerization capacity of orthodontic composites.
OBJECTIVE
The aim of this study was to evaluate, the cytotoxicity of orthodontic composites in vitro as a function of degree of conversion (DC) and the light curing units (LCU) employed on mouse fibroblast (L929).


METHODS
Cured samples of the composites Light bond (Reliance Orthodontic Products, Itasca, Illinois, USA), Ortho bracket paste (Bisco, Schaumburg, Illinois, USA), Opal bond MV (OPAL, South Jordan, Utah, USA), and Transbond XT (3M, Monrovia, California, USA) were prepared. Polymerization was performed with two LCUs: VALO Ortho (Ultradent, South Jordan, Utah, USA) is a third-generation LCU and Elipar S10 (3M, USA) is a second-generation LCU. Four samples were immersed in cell culture medium to obtain composite extracts. After incubation of L929 cell cultures with the extracts obtained, cytotoxicity was determined using the methyl tetrazolium test. Fourier transform infrared spectroscopy (FTIR) was used to evaluate DC for five samples. A multivariate analysis of variance (ANOVA), two-way ANOVA, and Tukey's honestly significant difference test were utilized for statistical analyses.


RESULTS
Cytotoxicity and DC of all tested composites (p < 0.001) and the interaction between composites and LCUs (p < 0.01) were significantly different. LCUs had no significant influence on the cytotoxicity and DC of composite materials (p > 0.05). The correlations between cell viability and DC were positive for three composites but statistically insignificant.


CONCLUSIONS
Composites and LCUs must be matched with one another to result in satisfactory maximal biocompatibility and DC. Opal Bond plasma light-emitting diode combination was a better choice for cell viability. Three composites showed a positive correlation between cytotoxicity and DC. Therefore high-intensity LCUs can be said to efficiently affect polymerization, and so, higher DC rates may achieve higher cell viability rates.
Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey bayramcorekci@yahoo.com.
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Cörekçi
Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
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Irgın
Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
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Halıcıoğlu
Department of Orthodontics, Faculty of Dentistry, Abant İzzet Baysal University, Bolu, Turkey.
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Dursun
Department of Medical Pharmacology, Faculty of Medicine, Abant İzzet Baysal University, Bolu, Turkey.
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Yavuz
D000704:Analysis of Variance; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000528:radiation effects / Q000633:toxicity; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D003188:Composite Resins / Q000528:radiation effects* / Q000633:toxicity*; D017220:Dentin-Bonding Agents / Q000528:radiation effects / Q000633:toxicity; D005347:Fibroblasts / Q000187:drug effects* / Q000473:pathology; D055115:Light-Curing of Dental Adhesives / Q000009:adverse effects* / Q000379:methods; D008689:Methacrylates / Q000528:radiation effects / Q000633:toxicity; D051379:Mice; D058105:Polymerization; D019279:Resin Cements / Q000528:radiation effects / Q000633:toxicity; D018570:Risk Assessment; D017550:Spectroscopy, Fourier Transform Infrared
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C429652:Reliance Light Bond; D019279:Resin Cements; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate
Cytotoxicity; FTIR; MTT; composites; curing light; degree of conversion