Fatigue behavior of zirconia-ceramic, galvano-ceramic, and porcelain-fused-to-metal fixed partial dentures.

Purpose: This study evaluated the fatigue behavior of three fixed partial dentures (FPDs) before and after artificial fatigue testing.

Materials And 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.