1. Department of Stomatology II, Faculty of Medicine and Nursery University of the Basque Country (UPV/EHU) Leioa Spain
2. Department of Nursery I, Faculty of Medicine and Nursery University of the Basque Country (UPV/EHU) Leioa Spain
3. Department of Immunology, Microbiology, Parasitology, Faculty of Medicine and Nursery University of the Basque Country (UPV/EHU) Leioa Spain
4. Centro Odontológico Médico Quirúrgico (Private Service) Barakaldo Spain