title: The effect of the use of a counter-torque device on the abutment-implant complex.
abstract: BACKGROUND
  Little is known about the condition of the abutment-screw joint before loading, after the development of the preload.
  
  
  OBJECTIVE
  This study examined the tightening force transmitted to the implant with and without the use of a counter-torque device during the tightening of the abutment screw.
  
  
  METHODS
  Forty Brânemark implants and 10 CeraOne, Estheticone, Procera, and AurAdapt abutments formed the experimental populations. Samples in each group were further divided into 2 groups, 1 group was tightened with a torque controller without the use of a counter-torque device, whereas the other used the counter-torque device. Samples were positioned in a special holder within the grips of a Tohnichi BTG-6 torque gauge for measuring transmitted forces.
  
  
  RESULTS
  There were significant differences (P =. 0001) in the tightening forces transmitted to the implant with and without the use of a counter-torque device when tightening the abutment screws.
  
  
  CONCLUSIONS
  An average of 91% of the recommended preload tightening torque was transmitted to the implant-bone interface in the absence of a counter-torque device. In all abutment systems, less than 10% of the recommended preload tightening torque was transmitted to the implant when the counter-torque device was used.
authors: School of Dentistry, University of North Carolina, Chapel Hill, NC 27599-7450, USA.
authors: L A
authors: LA
authors: Lang
authors: K B
authors: KB
authors: May
authors: R F
authors: RF
authors: Wang
mesh_terms: D000044:Dental Abutments; D017267:Dental Prosthesis Design / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D019094:Dental Prosthesis, Implant-Supported / Q000295:instrumentation* / Q000379:methods / Q000706:statistics & numerical data; D003799:Dental Stress Analysis / Q000706:statistics & numerical data; D006801:Humans; D019415:Torque