title: Accuracy of torque-limiting devices: A comparative evaluation.
abstract: BACKGROUND
  To prevent the loosening of implant screws, clinicians should be aware of the output torque values needed to achieve the desired preload. Accurate torque-control devices are crucial in this regard; however, little information is currently available comparing the accuracy of mechanical with that of electronic torque-control devices.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to identify and compare the accuracy of different types of torque-control devices.
  
  
  METHODS
  Devices from 5 different dental implant manufacturers were evaluated, including 2 spring-type (Straumann, Implance) mechanical devices (MTLD), 2 friction-type (Biohorizons, Dyna) MTLDs, and 1 (Megagen) electronic torque-control device (ETLD). For each manufacturer, 5 devices were tested 5 times with a digital torque tester, and the average for each device was calculated and recorded. The percentage of absolute deviations from the target torque values (PERDEV) were calculated and compared by using 1-way ANOVA. A 1-sample t test was used to evaluate the ability of each device to achieve its target torque value within a 95% confidence interval for the true population mean of measured values (α=.05 for all statistical analyses).
  
  
  RESULTS
  One-way ANOVAs revealed statistically significant differences among torque-control devices (P<.001). ETLD showed higher PERDEVs (28.33 ±9.53) than MTLDs (P<.05), whereas PERDEVS of friction-type (7.56 ±3.64) and spring-type (10.85 ±4.11) MTLDs did not differ significantly. In addition, devices produced by Megagen had a significantly higher (P<.05) PERDEV (28.33 ±9.53) other devices, whereas no differences were found in devices manufactured by Biohorizons (7.31 ±5.34), Dyna (7.82 ±1.08), Implance (8.43 ±4.77), and Straumann (13.26 ±0.79). However, 1-sample t tests showed none of the torque-control devices evaluated in this study were capable of achieving their target torque values (P<.05).
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, MTLDs were shown to be significantly more accurate than ETLDs. However, none of the torque-control devices evaluated were able to meet their target torque values successfully.
authors: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey. Electronic address: dthaydaralbayrak@hotmail.com.
authors: Haydar
authors: H
authors: Albayrak
authors: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors: Hasan Onder
authors: HO
authors: Gumus
authors: Research Assistant, Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors: Funda
authors: F
authors: Tursun
authors: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Pamukkale University, Denizli, Turkey.
authors: Hasan Huseyin
authors: HH
authors: Kocaagaoglu
authors: Assistant Professor, Department of Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors: Halil Ibrahim
authors: HI
authors: Kilinc
mesh_terms: D015921:Dental Implants; D003762:Dental Instruments; D066298:In Vitro Techniques; D019415:Torque
chemical_list: D015921:Dental Implants