1. Private Health Care, Physical Therapy and Rehabilitation, Bialystok, 79 Warsaw St., 15-201 Bialystok, Poland
2. Department of Dental Techniques, Medical University of Bialystok, 13 Washington St., 15-269 Bialystok, Poland
3. Department of General Dentistry, Medical University of Lodz, 251 Pomorska St., 92-213 Lodz, Poland
4. Department of Prosthodontics, Medical University of Bialystok, 24A M. Sklodowskiej-Curie St., 15-276 Bialystok, Poland