TY - JOUR
T1 - Effect of implant-abutment connection design on reliability of crowns
T2 - Regular vs. horizontal mismatched platform
AU - Freitas Júnior, Amilcar C.
AU - Bonfante, Estevam A.
AU - Silva, Nelson R.F.A.
AU - Marotta, Leonard
AU - Coelho, Paulo G.
PY - 2012/9
Y1 - 2012/9
N2 - Objectives: To evaluate the reliability and failure modes of regular and horizontal mismatched platforms for implant-abutment connection varying the implant diameter. Material and methods: Regular (REG, n = 21, 4.0-mm-diameter implant) and horizontal mismatched (HM, n = 21, 4.6-mm-diameter implant) platform Ti-6Al-4V implants were restored with proprietary identical Ti-6Al-4V abutments and metal crowns (cobalt-chrome, Wirobond® 280, BEGO, Bremen, Germany) cemented. Mechanical testing comprised step-stress accelerated-life testing, where crowns were distributed in three loading profiles for fatigue in water, producing timely and clinically relevant fractures. The probability of failure vs. cycles (95% two-sided confidence intervals) was calculated and plotted using a powerlaw relationship for damage accumulation, Weibull modulus (95% two-sided confidence intervals) and then the reliability for a mission of 50,000 cycles at 125 N load (95% two-sided confidence interval) were calculated. Fractography was performed in the scanning electron microscope. Results: The β-value for group REG (β = 1.37) indicated that fatigue was a factor accelerating the failure, whereas load alone dictated the failure for group HM (β = 0.71). The Weibull parameter contour plot showed no significantly different Weibull modulus for REG (10.24) compared to HM (10.20) and characteristic strength of 162.6 and 166.8 N, respectively (P > 0.91). The calculated reliability for a mission of 50,000 cycles at 125 N load was not significantly different (0.71 for REG and 0.73 for HM). Abutment screw failure was the chief failure mode. Conclusions: Reliability was not significantly different between groups and failure modes were similar.
AB - Objectives: To evaluate the reliability and failure modes of regular and horizontal mismatched platforms for implant-abutment connection varying the implant diameter. Material and methods: Regular (REG, n = 21, 4.0-mm-diameter implant) and horizontal mismatched (HM, n = 21, 4.6-mm-diameter implant) platform Ti-6Al-4V implants were restored with proprietary identical Ti-6Al-4V abutments and metal crowns (cobalt-chrome, Wirobond® 280, BEGO, Bremen, Germany) cemented. Mechanical testing comprised step-stress accelerated-life testing, where crowns were distributed in three loading profiles for fatigue in water, producing timely and clinically relevant fractures. The probability of failure vs. cycles (95% two-sided confidence intervals) was calculated and plotted using a powerlaw relationship for damage accumulation, Weibull modulus (95% two-sided confidence intervals) and then the reliability for a mission of 50,000 cycles at 125 N load (95% two-sided confidence interval) were calculated. Fractography was performed in the scanning electron microscope. Results: The β-value for group REG (β = 1.37) indicated that fatigue was a factor accelerating the failure, whereas load alone dictated the failure for group HM (β = 0.71). The Weibull parameter contour plot showed no significantly different Weibull modulus for REG (10.24) compared to HM (10.20) and characteristic strength of 162.6 and 166.8 N, respectively (P > 0.91). The calculated reliability for a mission of 50,000 cycles at 125 N load was not significantly different (0.71 for REG and 0.73 for HM). Abutment screw failure was the chief failure mode. Conclusions: Reliability was not significantly different between groups and failure modes were similar.
KW - Diameter shifting
KW - Fractography
KW - Implant-abutment connection
KW - Reliability
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U2 - 10.1111/j.1600-0501.2011.02257.x
DO - 10.1111/j.1600-0501.2011.02257.x
M3 - Article
C2 - 22092300
AN - SCOPUS:84865306187
SN - 0905-7161
VL - 23
SP - 1123
EP - 1126
JO - Clinical Oral Implants Research
JF - Clinical Oral Implants Research
IS - 9
ER -