original article OA A comparative study on accuracy of the implant torque devices for screw tightening Hi-Chan Jung 1, Chang-Mo Jeong 2 1 Graduate student, DDS,MSD Dept of Prosthodontic Dentistry, College of Dentistry, Pusan National University 2 Professor, DDS,MSD,PhD, Dept of Prosthodontic Dentistry, College of Dentistry, Pusan National University Abstract This study evaluated the accuracy and the consistency of torque which were delivered from four mechanical torque devices and one electric torque device used routinely in our department. To measure the torque output of each torque device, torque device positioned in the jaws of torque gauge was and then target torque of 20Ncm was applied. The delivered torque was recorded thirty times for each device. Within the limits of this study design, the following conclusions can be made; 1. Torque output of each individual device deviated in varying ranges from target torque values. 2. The means of torque value delivered from five torque devices were within the deviation of 10% of the target torque values. 3. 3i Restorative torque indicator and Nobel Biocare Prosthetic manual torque wrench produced the most accurate and consistent torque values. 4. Osstem Torque wrench recorded the largest variations from target torque values. 5. The electric torque device was the only one which delivered the lower torque values than the target torque value. Key words : electric torque device, mechanical torque device, screw tightening. 2 Implantology 2003. 10
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original article A B C D Fig. 1. A, Torque wrench(osstem implant) B, SAE precision torque wrench(sae dental Vertriebs GMBH) C, Restorative torque indicator(3i implant innovation) D, Prosthetic manual torque wrench(nobel Biocare AB) E, Torque controller(nobel Biocare AB) E Fig. 2. Torque wrench positioned in the jaws of the Torque Gauge. 4 Implantology 2003. 10
IMPLANTOLOGY Table. 1. Torque value(ncm) registrated by torque gauge and Duncan s multiple comparison Torque device Mean SD Duncan s grouping Torque wrench 22.06 1.23 A SAE precision torque wrench 21.40 0.28 B Restorative torque indicator 20.60 0.16 C Prosthetic manual torque wrench 20.19 0.46 C Torque controller 18.67 0.55 D * The same letter denotes groups that were not significantly different from each other(p>0.05). Table. 2. Maximum and Minimum torque value(ncm) for torque device Torque device Maximum Minimum Torque wrench 24.60 19.50 SAE precision torque wrench 22.00 21.00 Restorative torque indicator 20.90 20.20 Prosthetic manual torque wrench 21.20 19.20 Torque controller 19.90 17.40 2003. 10 Implantology 5
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IMPLANTOLOGY 25 Mean torque(ncm) 20 15 10 5 0 Torque wrench SAE precision torque wrench Restorative torque indicator Prosthetic manual torque wrench Torque controller Torque device Fig. 3. Graphic presentation of differences in mean torque value registrated by torque gauge 2003. 10 Implantology 7
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