title: Fatigue behavior of zirconia-ceramic, galvano-ceramic, and porcelain-fused-to-metal fixed partial dentures.
abstract: OBJECTIVE
  This study evaluated the fatigue behavior of three fixed partial dentures (FPDs) before and after artificial fatigue testing.
  
  
  METHODS
  Sixty, three-unit zirconia-ceramic (ZC), galvano-ceramic (GC), and porcelain-fused-to-metal (PFM) FPDs (N = 20) were fabricated. Ten specimens from each group were exposed to fatigue testing by being thermocycled (5 to 55°C, 10,000 cycles) and loaded (100,000 cycles, 50 N, 0.5 Hz). All specimens were then subjected to occlusal loading in a universal testing machine until fracture. The fractures were characterized using scanning electron microscopy. Data were analyzed using one-way ANOVA followed by Tukey's significant difference post hoc test and the paired t-test. The chi-squared test was used to evaluate the type of fracture (α = 0.05).
  
  
  RESULTS
  The mean fracture loads of non-fatigued and fatigued specimens for ZC were 2434.9 ± 154.3 and 2333.1 ± 183.0 N, respectively; for GC were 1678.1 ± 211.6 and 1475.8 ± 227.9 N, respectively; and 1878.5 ± 176.5 and 1687.8 ± 162.2 N, respectively, for PFM restorations. Significant differences were observed between fatigued and non-fatigued specimens of both the GC group and PFM group (p < 0.05), but not between fatigued and non-fatigued ZC specimens (p > 0.05). Differences between the PFM and GC specimens were not statistically significant for fatigued or non-fatigued specimens (p > 0.05). Fracture types did not differ significantly among groups.
  
  
  CONCLUSIONS
  ZC specimens were not significantly affected by fatigue, whereas GC and PFM specimens were affected. All tested restorations have the potential to withstand occlusal forces applied in the posterior region.
authors.affiliation: Department of Prosthodontics, Erciyes University Faculty of Dentistry, Kayseri, Turkey.
authors.forename: Zekiye
authors.initials: Z
authors.lastname: Eroğlu
authors.affiliation: Department of Prosthodontics, Erciyes University Faculty of Dentistry, Kayseri, Turkey.
authors.forename: Aysegul G
authors.initials: AG
authors.lastname: Gurbulak
mesh_terms: D001732:Bite Force; D002516:Ceramics / Q000737:chemistry*; D002858:Chromium Alloys / Q000737:chemistry; D017076:Computer-Aided Design; D000044:Dental Abutments; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000295:instrumentation; D003779:Denture Design; D003830:Denture, Partial, Fixed; D055664:Electrochemical Techniques; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D003765:Models, Dental; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D015040:Zirconium / Q000737:chemistry*
chemical_list: D002858:Chromium Alloys; D003764:Dental Materials; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide
keywords: All-ceramic; electroforming; fatigue test; fixed partial denture; zirconia ceramic