Fatigue reliability of 3 single-unit implant-abutment designs.
OBJECTIVE
Because the mechanical behavior of the implant-abutment system is critical for the longevity of implant-supported reconstructions, this study evaluated the fatigue reliability of different implant-abutment systems used as single-unit crowns and their failure modes.


METHODS
Sixty-three Ti-6Al-4V implants were divided in 3 groups: Replace Select (RS); IC-IMP Osseotite; and Unitite were restored with their respective abutments. Anatomically correct central incisor metal crowns were cemented and subjected to separate single load to failure tests and step-stress accelerated life testing (n = 18). A master Weibull curve and reliability for a mission of 50,000 cycles at 200 N were calculated. Polarized-light and scanning electron microscopes were used for failure analyses.


RESULTS
The load at failure mean values during step-stress accelerated life testing were 348.14 N for RS, 324.07 N for Osseotite, and 321.29 N for the Unitite systems. No differences in reliability levels were detected between systems, and only the RS system mechanical failures were shown to be accelerated by damage accumulation. Failure modes differed between systems.


CONCLUSIONS
The 3 evaluated systems did not present significantly different reliability; however, failure modes were different.
Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
Leandro M
LM
Martins
Estevam A
EA
Bonfante
Ricardo A
RA
Zavanelli
Amilcar C
AC
Freitas
Nelson R F A
NR
Silva
Leonard
L
Marotta
Paulo G
PG
Coelho
D000497:Alloys; D003442:Crowns; D000044:Dental Abutments; D003722:Dental Alloys; D059605:Dental Implant-Abutment Design; D019250:Dental Implants, Single-Tooth; D017268:Dental Prosthesis Retention / Q000295:instrumentation; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D019544:Equipment Failure Analysis; D007180:Incisor; D008859:Microscopy, Polarization; D016019:Survival Analysis; D014025:Titanium
D000497:Alloys; D003722:Dental Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium