Load to failure of different zirconia implant abutments with titanium components

Abutments with a zirconia superstructure and a titanium insert have recently become popular. Although they have been tested under static load, their performance under simulated mastication is not well known.

The purpose of this in vitro study was to compare the cyclic load to failure of 3 types of zirconia abutments with different mechanisms of retention of the zirconia to the titanium interface.

Fifteen implants (n=5 per system) and abutments (3 groups: 5 friction fit [Frft]; 5 bonded; and 5 titanium ring friction fit [Ringfrft]) were used. Abutments were thermocycled in water between 5°C and 55°C for 15000 cycles and then cyclically loaded for 20000 cycles or until failure at a frequency of 2 Hz by using a sequentially increased loading protocol up to a maximum of 720 N. The load to failure for each group was recorded, and 1-way analysis of variance was performed.

The mean load-to-failure values for the Frft group was 526 N, for the Bond group 605 N, and for the Ringfrft group 288 N. A statistically significant difference was found among all abutments tested (P<.05).

Abutments with the bonded connection showed the highest load-to-failure value, and the abutment with the titanium ring friction fit connection showed the lowest load-to-failure value.