IADR Abstract Archives

Biomechanical Evaluation of Platform Switched Implant-Abutment Connections

Objective: Using the step-stress accelerated life testing and three-dimensional finite element analysis, the aim of this study was to assess the effect of abutment's diameter shifting on reliability and stress distribution within the implant-abutment connection of anterior single-unit restorations for internal and external hexagon implants. The postulated hypothesis was that platform-switched implants would result in increased stress concentration within the implant-abutment connection, leading to the systems’ lower reliability on laboratory mechanical testing.

Method: Eighty-four implants were divided in four groups (n=21): REG-EH and SWT-EH (regular and switched-platform implants with external connection, respectively); REG-IH and SWT-IH (regular and switched-platform implants with internal connection, respectively). Use-level probability Weibull curves and reliability were calculated. Four finite element models reproducing the characteristics of specimens used in laboratory testing were created to evaluate the stress distribution (σvM) within the implant-abutment complex.

Result: The Beta values for groups SWT-EH (1.31), REG-EH (1.55), SWT-IH (1.83) and REG-IH (1.82) indicated that fatigue accelerated the failure of all groups. The higher levels of σvM within the implant-abutment connection observed for platform-switched implants (groups SWT-EH and SWT-IH) were in agreement with the lower reliability observed for the external hex implants, but not for the internal hex implants. The reliability 90% confidence intervals (50,000 cycles at 300N) were 0.53(0.33-0.70), 0.93(0.80-0.97), 0.99(0.93-0.99) and 0.99(0.99-1.00), for the SWT-EH, REG-EH, SWT-IH, and REH-IH, respectively. Failure modes were similar in all groups.

Conclusion: The postulated hypothesis was partially accepted. The higher levels of stress observed within implant-abutment connection when reducing abutment diameter resulted in lower reliability for external hex implants, but not for internal hex implants.

IADR/LAR General Session
2012 IADR/LAR General Session (Iguaçu Falls, Brazil)
Iguaçu Falls, Brazil
2012
73
Prosthodontics Research
  • Freitas, Amilcar  ( New York University, New York, NY, USA )
  • Rocha, Eduardo  ( Sao Paulo State University - Brazil, Aracatuba - SP, N/A, Brazil )
  • Almeida, Erika  ( New York University, New York, NY, USA )
  • Bonfante, Estevam  ( UNIGRANRIO University, Duque de Caxias, RJ, N/A, Brazil )
  • Martini, Ana Paula  ( Universidade Est. Paulista Julio Mesquita, Araçatuba-SP, N/A, Brazil )
  • Anchieta, Rodolfo  ( Universidade Est. Paulista Julio Mesquita, Araçatuba-SP, N/A, Brazil )
  • Silva, Nelson  ( New York University, New York, NY, USA )
  • Thompson, Van  ( New York University, New York, NY, USA )
  • Coelho, Paulo  ( New York University, New York, NY, USA )
    • Oral Session
    Frechette Competition
    06/20/2012