CC BY-NC-ND 4.0 · Eur J Dent 2013; 07(03): 267-271
DOI: 10.4103/1305-7456.115407
Original Article
Dental Investigation Society

Stability of external and internal implant connections after a fatigue test

Paulo Cesar Pinheiro Feitosa
1   Department of Prosthodontics, Dentistry School, University of Taubate, Taubate-SP, Brazil
Ana Paula Barbosa de Lima
1   Department of Prosthodontics, Dentistry School, University of Taubate, Taubate-SP, Brazil
Laís Regiane Silva-Concílio
1   Department of Prosthodontics, Dentistry School, University of Taubate, Taubate-SP, Brazil
William Cunha Brandt
2   Department of Dentistry, Area of Implantology, University of Santo Amaro, São Paulo-SP, Brazil
Ana Christina Claro Neves
1   Department of Prosthodontics, Dentistry School, University of Taubate, Taubate-SP, Brazil
› Author Affiliations
Further Information

Publication History

Publication Date:
26 September 2019 (online)


Objective: The objective of this study was to compare the torque and detorque values of screw intermediates of external hexagon, internal hexagon, and Morse taper implants in single restorations before and after mechanical cycling. Materials and Methods: The study sample was divided into three groups (n = 10) as follows: group EH - external hexagon implant, group IH - internal hexagon implant, and group MT - Morse taper implant. Universal abutments were screwed on the implants, and metal crowns were cemented onto the abutment. The samples were submitted to a mechanical testing of 1 million cycles, with a frequency of 8 cycles per second under a 400 N load. The application and registration of the screw torque (T0) and detorque (T1) values of the intermediate were performed before and after the test. The results were statistically evaluated by analysis of variance (ANOVA) and Tukey′s test (α = 0.05). Results: There was no difference between the values of T0 and T1 in the intra-group samples. However, the inter-group difference in T0 between the EH (12.8 N cm) and MT (18.6 N cm) groups and in T1 between the EH (10.4 N cm) and IH (13.8 N cm), EH and MT (19.4 N cm), and MT and IH (P = 0.001) groups were significant. The MT group showed a lower variation of T0 and T1. Conclusion: The internal implants, particularly MT, showed better stability in these cases when used for single restorations.


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