Biocompatibility and setting time of gray Portland cement clinker with or without calcium sulfate - Bramante, Clovis Monteiro; Oropeza, Ramiro Marcelo Ortiz; Assis, Gerson Francisco de; Garcia, Roberto Brandão; Duarte, Marco Antonio Hungaro; Bramante, Alexandre Silva; Bernardineli, Norberti; Moraes, Ivaldo Gomes de (Dental Press Endodontics, 2012)