Fracture Resistance of a Two-Piece Zirconia Implant System after Artificial Loading and/or Hydrothermal Aging-An In Vitro Investigation.

ABSTRACT

The purpose of the present study was to assess the fracture resistance of a two-piece alumina-toughened zirconia implant system with a carbon-reinforced PEEK abutment screw. METHODS: Thirty-two implants with screw-retained zirconia abutments were divided into four groups of eight samples each. Group 0 (control group) was neither loaded nor aged in a chewing simulator; group H was hydrothermally aged; group L was loaded with 98 N; and group HL was subjected to both hydrothermal aging and loading in a chewing simulator. One sample of each group was evaluated for t-m phase transformation, and the others were loaded until fracture. A one-way ANOVA was applied to evaluate differences between the groups. RESULTS: No implant fracture occurred during the artificial chewing simulation. Furthermore, there were no statistically significant differences (p > 0.05) between the groups in terms of fracture resistance (group 0 783 ± 43 N; group H 742 ± 43 N; group L 757 ± 86 N; group HL 740 ± 43 N) and bending moment (group 0 433 ± 26 Ncm; group H 413 ± 23 Ncm; group L 422 ± 49 Ncm; group HL 408 ± 27 Ncm). CONCLUSIONS: Within the limitations of the present investigation, it can be concluded that artificial loading and hydrothermal aging do not reduce the fracture resistance of the investigated implant system.