In vitro cytotoxicity of different thermoplastic materials for clear aligners.OBJECTIVES
 To investigate the in vitro cytotoxicity of different thermoplastic materials for clear aligners on human primary gingival fibroblasts (HGFs).


 Three out of four materials (Duran, Biolon, Zendura) were assessed as thermoformed and nonthermoformed, whereas the SmartTrack was assessed only as thermoformed.  In the comparison between nonthermoformed and thermoformed materials for Duran, Biolon, and Zendura, the thermoformed materials showed the highest level of cytotoxicity (P < .001).


 Biolon was the most cytotoxic and the thermoforming process increased the cytotoxicity of the materials.
THERM