1. Periodontal Biology Laboratory, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
2. Department of Conservative Dentistry, Faculty of Dentistry, Universidad de Chile, Santiago, Chile
3. Department of Periodontology, School of Dentistry, Universidad Científica del Sur, Lima, Peru
4. Faculty of Dentistry, Universidad Andres Bello, Santiago, Chile
5. Health Sciences Division, Faculty of Dentistry, Universidad Santo Tomás, Bucaramanga, Colombia