Objectives: The purpose of this study was to evaluate the effects of two different implant abutment materials on screw-loosening before and after cyclic loads. Material and Methods: The UCLA type of single tooth implant superstructures were fabricated with type III gold alloy and zirconia/alumina composite (ZrO2/Al2O3) for cyclic loads. Five abutments of each group were connected with implant fixtures with titanium alloy screws tightened with 20Ncm. Special jig was used for holding the external hexagon type fixtures. To evaluate the initial torque loss of each screw a set of 20 times of consecutive closing/opening torque was measured. Five specimens of each group were loaded with the use of cyclic loading device with 200 N of force at 30 degree angle with a frequency of 2 Hz. After 1million cyclic loads opening torque values were recorded. Statistical analyses were used for evaluation of the data. Results: 1) Titanium alloy screw tightened in 20Ncm, a cold-welding phenomenon was not observed during the 20 times of closing/opening cycle. (p=0.11, p=0.18) 2) Repeated opening and closing of the abutment screw caused progressive decrease of opening torque. (p=0.014) 3) there was no significant difference in torque loss between gold alloy abutment and ceramic (ZrO2/Al2O3) abutment after 1,000,000 cyclic loads. (p=0.92) Conclusions: Within the limitations of this study, following conclusions were drawn: The abutment materials do not affect the initial torque loss. There was no significant difference in screw loosening after 1,000,000 cyclic loads between two abutment materials.

Back to the Scientific Program Program
Back to the Joint Meeting of the Continental European, Israeli, and Scandinavian (NOF) Divisions of the IADR (August 25 -- 28, 2004)

Top Level Search