Cytotoxicity of three commercial orthodontic elastomeric ligature brands Peerapong Tua-ngam, Nittaya Jira-anankul, Niwat Anuwongnukroh, Surachai Dechkunakorn and Pasaree Laokijcharoen MATEC Web Conf., 108 (2017) 06004 Published online: 31 May 2017 DOI: 10.1051/matecconf/201710806004