1. University Dental Clinical Centre , Departement of periodontology and oral pathology, Faculty of dentistry , “Ss. Cyril and Methodius University” , Skopje , R.N. Macedonia
2. University Dental Clinical Centre , Departement of periodontology and oral pathology , Skopje, R.N. Macedonia
3. PZU „ Ilinden 96 “ Skopje , R.N. Macedonia
4. „Dr. Spasovski “ Skopje , R.N. Macedonia