1. Division of Oral Rehabilitation, School of Dentistry, Universidad Científica Del Sur, Lima, Perú.
2. Division of Orthodontic, School of Dentistry, Universidad Científica Del Sur, Lima, Perú.
3. Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos, Rio Branco, Porto Alegre, RS, Brazil.