Long-term surface hardness and monomer conversion of a nanofilled and a microhybrid composite resin - Jassé, Fernanda Ferreira; Borges, Carlos Henrique Braga; Tonetto, Mateus Rodrigues; Rastelli, Alessandra Nara de Souza; Bagnato, Vanderlei Salvador; Campos, Edson Alves de; Santos, Reidson Stanley Soares dos; Bandeca, Matheus Coelho; Saad, Jose Roberto Cury (Journal of Contemporary Dental Practice, 2013)