title: Outcome of zirconia partial fixed dental prostheses made by predoctoral dental students: A clinical retrospective study after 3 to 7 years of clinical service.
abstract: BACKGROUND
  Zirconia has an established role in fixed prosthodontics, especially for single crowns. Whether it is durable enough for fixed dental prostheses (FDPs) in the long term is yet unclear.
  
  
  OBJECTIVE
  The purpose of this retrospective study was to evaluate the outcome of FDPs made by predoctoral students after 3 to 7 years of clinical service.
  
  
  METHODS
  A total of 102 patients received 120 zirconia FDPs (range, 3-12 units; mean, 4.5 units) between 2007 and 2010. Materials used were Zirkonzahn Zirconia (Zirkonzahn), NobelProcera Zirconia (Nobel Biocare), and Prettau Zirconia (Zirkonzahn). Veneering porcelain was hand-layered on Zirkonzahn Zirconia (GC Initial Zr; GC Europe) and Nobel Procera Zirconia (VITA VM 9; VITA Zahnfabrik). Prettau Zirconia was monolithic and had no veneering porcelain. Success and survival rates were calculated using Kaplan-Meier survival analysis. Ethics approval was obtained from the Ethical Committee of the Northern Ostrobothnia Hospital District (100/2013).
  
  
  RESULTS
  The 76 participants examined (75%) had received 88 zirconia FDPs. The mean follow-up period was 4.9 years (range, 3-7 years). The most common complication was chipping of the veneering porcelain in 13 of 88 FDPs (14.7%). The success rate of the zirconia-based partial FDPs after 4.9 years was 89%, and the survival rate was 100%.
  
  
  CONCLUSIONS
  The success rate of the zirconia-based partial FDPs after 4.9 years was 89%, and the survival rate was 100%.
authors: Research Assistant, Research Center for Oral Health Sciences, Faculty of Medicine, University of Oulu and Medical Research Center, Oulu, Finland. Electronic address: juha.t.pihlaja@gmail.com.
authors: Juha
authors: J
authors: Pihlaja
authors: Senior Lecturer, Research Center for Oral Health Sciences, Faculty of Medicine, University of Oulu and Medical Research Center, Oulu, Finland.
authors: Ritva
authors: R
authors: Näpänkangas
authors: Professor, Research Center for Oral Health Sciences, Faculty of Medicine, University of Oulu and Medical Research Center, Oulu, Finland.
authors: Aune
authors: A
authors: Raustia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003776:Dental Porcelain / Q000627:therapeutic use; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003830:Denture, Partial, Fixed; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013335:Students, Dental; D015040:Zirconium / Q000627:therapeutic use*
chemical_list: D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide