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Reliability and failure modes of anterior single‐unit implant‐supported restorations
Author(s) -
Freitas Amilcar C.,
Bonfante Estevam A.,
Martins Leandro M.,
Silva Nelson R. F. A.,
Marotta Leonard,
Coelho Paulo G.
Publication year - 2012
Publication title -
clinical oral implants research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.407
H-Index - 161
eISSN - 1600-0501
pISSN - 0905-7161
DOI - 10.1111/j.1600-0501.2011.02269.x
Subject(s) - crown (dentistry) , implant , maxillary central incisor , abutment , dentistry , reliability (semiconductor) , materials science , orthodontics , implant failure , dental prosthesis , incisor , dental abutments , medicine , structural engineering , surgery , engineering , physics , power (physics) , quantum mechanics
Purpose Failures of implant‐abutment connections have been observed clinically, especially in single‐tooth replacements. This study sought to evaluate the reliability and failure modes of implant‐supported anterior crowns restored with different implant systems. Materials and methods Forty‐two Ti‐6Al‐4V dental implants (~4 mm diameter) were used for single anterior crown replacement and divided into two groups according to tested system: (NB) Replace Select system, Nobel Biocare ( n = 21); and (IL) Internal connection system, Intra‐Lock International ( n = 21). Proprietary abutments were screwed to the implants and anatomically correct maxillary central incisor metal crowns were cemented and subjected to step‐stress‐accelerated life testing in water. Use‐level probability Weibull curves and reliability for a mission of 50,000 cycles at 200 N (95% 2‐sided confidence intervals) were calculated. Polarized‐light and scanning electron microscopes were used for failure analyses. Results The Beta values for NB and IL (2.09 and 2.05, respectively) indicated that fatigue accelerated the failure of both groups. The calculated reliability for the NB system (0.81) was lower than for the IL system (0.96), but no significant difference was observed between groups. Screw and abutment fracture was the chief failure mode in group NB, while screw fracture was most representative in specimens of group IL. Conclusions Reliability of implant‐supported maxillary central incisor crowns was not significantly different between NB and IL abutments. Failure modes differed between implant systems.