Marcio Longoni1, Darlene Ribeiro dos Santos Gerzson2, Denise Cantarelli Machado3, Maria Perpetua Mota Freitas4*
Dr. Maria Perpetua Mota Freitas, PhD in Dental Materials and MSc in Orthodontics – PUCRS, Professor, Department of Orthodontics, Lutheran University of Brazil, Canoas, Brazil.