Reliability and failure modes of internal conical dental implant connections

Amilcar C. Freitas-Júnior, Erika O. Almeida, Estevam A. Bonfante, Nelson R.F.A. Silva, Paulo G. Coelho

Research output: Contribution to journalArticlepeer-review


Objective: Biological and mechanical implant-abutment connection complications and failures are still present in clinical practice, frequently compromising oral function. The purpose of this study was to evaluate the reliability and failure modes of anterior single-unit restorations in internal conical interface (ICI) implants using step-stress accelerated life testing (SSALT). Materials and methods: Forty-two ICI implants were distributed in two groups (n = 21 each): group AT-OsseoSpeed TX (Astra Tech, Waltham, MA, USA); group SV-Duocon System Line, Morse Taper (Signo Vinces Ltda., Campo Largo, PR, Brazil). The corresponding abutments were screwed to the implants and standardized maxillary central incisor metal crowns were cemented and subjected to SSALT in water. Use-level probability Weibull curves and reliability for a mission of 50,000 cycles at 200 N were calculated. Differences between groups were assessed by Kruskal-Wallis along with Bonferroni's post-hoc tests. Polarized-light and scanning electron microscopes were used for failure analyses. Results: The Beta (β) value derived from use level probability Weibull calculation was 1.62 (1.01-2.58) for group AT and 2.56 (1.76-3.74) for group SV, indicating that fatigue was an accelerating factor for failure of both groups. The reliability for group AT was 0.95 and for group SV was 0.88. Kruskal-Wallis along with Bonferroni's post-hoc tests showed no significant difference between the groups tested (P > 0.27). In all specimens of both groups, the chief failure mode was abutment fracture at the conical joint region and screw fracture at neck's region. Conclusions: Reliability was not different between investigated ICI connections supporting maxillary incisor crowns. Failure modes were similar.

Original languageEnglish (US)
Pages (from-to)197-202
Number of pages6
JournalClinical Oral Implants Research
Issue number2
StatePublished - Feb 2013


  • Fractography
  • Implant-supported prostheses
  • Internal conical interface connection
  • Step-stress accelerated life testing
  • Weibull

ASJC Scopus subject areas

  • Oral Surgery


Dive into the research topics of 'Reliability and failure modes of internal conical dental implant connections'. Together they form a unique fingerprint.

Cite this