Atomic absorption spectrometry and scanning electron microscopy evaluation of concentration of calcium ions and smear layer removal with root canal chelators - Spanó, Júlio César Emboava; Silva, Ricardo Gariba; Guedes, Débora Fernandes Costa; Sousa Neto, Manoel Damião de; Estrela, Carlos; Pécora, Jesus Djalma (Journal of Endodontics, 2009)