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Comparative Study
. 2008 Jan-Feb;16(1):55-8.
doi: 10.1590/s1678-77572008000100011.

Preload and torque removal evaluation of three different abutment screws for single standing implant restorations

Rafael Augusto Stüker  1 , Eduardo Rolim Teixeira, João Carlos Pinheiro Beck, Nilza Pereira da Costa
Affiliations
Comparative Study

Preload and torque removal evaluation of three different abutment screws for single standing implant restorations

Rafael Augusto Stüker et al. J Appl Oral Sci. 2008 Jan-Feb.

Abstract

Several authors still consider the mechanical problems of fracture and component loosening as the main causes of failure of implant-supported restorations. The purpose of this in vitro study was to compare the preload of three types of screw for transmucosal abutment attachment used in single implant-supported prosthesis through strain gauge and removal torque measurements. Three external hex fixtures were used, and each received a transmucosal abutment (Cera One), which was fixed to the implant with its respective screw: Group A- gold screw, Group B- titanium screw and Group C- surface-treated titanium screw (Ti-Tite). Ten screws of each type were attached applying a 30.07+/-0.28 Ncm torque force and maintained in position for 5 minutes. After this, the preload values were measured using strain gauges and a measurement cell. Gold screws presented higher preload values (131.72+/-8.98 N), followed by surface-treated titanium screws (97.78+/-4.68 N) and titanium screws (37.03+/-5.69 N). ANOVA (p<0.05) and Tukey's test (p<0.05) were applied. Statistically significant differences were found among the groups for both preload and removal torque values. In conclusion, gold screws may be indicated to achieve superior longevity of the abutment-implant connection and, consequently, prosthetic restoration due to greater preload values yielded.

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Figures

FIGURE 1
FIGURE 1. a) Gold (A), titanium (B) and Surface-treated titanium (C) abutment screws (Conexão®, Sistemas de Prótese Ltda., São Paulo, Brazil); b) Load cell adapted from the literature; c) Cera One® abutment in position; d) Square hand wrench attached to the torquemeter
FIGURE 2
FIGURE 2. Preload averages of each analyzed group
FIGURE 3
FIGURE 3. Torque removal averages of three analyzed groups
See this image and copyright information in PMC

References

    1. Al Rafee MA, Nagy WW, Fournelle RA, Dhuru VB, Tzenakis GK, Pechous CE. The effect of repeated torque on the ultimate tensile strength of slotted gold prosthetic screws. J Prosthet Dent. 2002;88(2):176–182. - PubMed
    1. Cantwell A, Hobkirk JA. Preload loss in gold prosthesis-retaining screws as a function of time. Int J Oral Maxillofac Implants. 2004;19(1):124–132. - PubMed
    1. Carr AB, Brunski JB, Hurley E. Effects of fabrication, finishing, and polishing procedures on preload in prostheses using conventional gold and plastic cylinders. Int J Oral Maxillofac Implants. 1996;11(5):589–598. - PubMed
    1. Haack JE, Sakaguchi RL, Sun T, Coffey JP. Elongation and preload stress in dental implant abutment screws. Int J Oral Maxillofac Implants. 1995;10(5):529–536. - PubMed
    1. Hoyer SA, Stanford CM, Buranadham S, Fridrich T, Wagner J, Gratton D. Dynamic fatigue properties of the dental implant-abutment interface: Joint opening in wide-diameter versus standard-diameter hex-type implants. J Prosthet Dent. 2001;85(6):599–607. - PubMed

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