Load fatigue performance of a single-tooth implant abutment system: effect of diameter.
OBJECTIVE
This study investigated the load fatigue performance of narrow-, regular-, and wide-diameter CeraOne (Nobel Biocare) single-tooth implants and abutments.


METHODS
Five samples of each implant-abutment combination in 3 different widths were tested at 3 applied screw torque levels (recommended torque, recommended torque +20%, and recommended torque -20%). A rotational load fatigue machine was used to apply a 21-N load, at an angle of 45 degrees to the long axis of the specimens. This loading produced an effective bending moment of 35 Ncm at the abutment-implant interface. An upper cyclic limit was set at 5 x 10(6) load cycles for all specimens.


RESULTS
Two-way analysis of variance revealed a significant difference between narrow-diameter and wide-diameter implant test groups but no significant difference between the 3 torque levels for each implant diameter. In the narrow-diameter group, 6 of the 15 specimens failed (5 abutment screw failures and 1 implant failure). In the regular-diameter group, 3 of the 15 specimens failed (2 implant failures and 1 abutment screw failure). There were no failures in the wide-diameter group.


CONCLUSIONS
The results of this study indicate that the abutment screw is not the only potential failure location. The possibility of implant fracture clinically has been previously reported for prostheses supported by both single- and multiple-implant prostheses.


CONCLUSIONS
The wide-diameter CeraOne single-tooth implant system demonstrated superior load fatigue performance. For clinical situations with significant functional loading, the narrow-diameter implants would be at a greater risk of fatigue failure.
Quek
Christopher E
CE
Department of Restorative Dentistry, National Dental Centre, Republic of Singapore.
Tan
Keson B
KB
Nicholls
Jack I
JI
D000044:Dental Abutments; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D012399:Rotation; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D019415:Torque; D015036:Zinc Phosphate Cement / Q000737:chemistry
D015036:Zinc Phosphate Cement