Effects of plasma-emulating light emitting diode (LED) versus conventional LED on cytotoxic effects of orthodontic cements as a function of polymerization capacity.

Objectives: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).Materials and 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 LCU...