Accuracy value evaluation of torque wrenches used in dental offices of Tabriz city in the year of 1397 Author: Nafiseh birang Supervisor: Dr. Shima Ghasemi Advisor: Dr. Amin nourizadeh No:

Abstract

Background/aim: although implant treatments are totally successful treatments, but outbreak of prosthodontics and surgical complications are common. Loosening of abutment screw is one of the common prosthodontic complications of implant treatments which one of the causes of making this problem is lose of accuracy of torque wrenches. So, in this study we inspect the accuracy value of torque wrenches used in dental offices of Tabriz city in the year of 1397. Methods and materials: in this descriptive-analytical study which was done cross-sectional, 30different torque wrenches were evaluated( types of Dentis, Osstem, Dio and Neo biotech). As to determine the value of torque wrenches accuracy, in the torque which was determined in the producing factory of screw, a digital torque-evaluator (Digital torque meter, TQ-8800, Lutron, Taiwan) was used. The value of accuracy of torque wrenches were evaluated with the difference between the measured torque and target-torque. The data gathered from this study were evaluated with statistical-descriptive methods (percentage abundance, average). The outcome data were analyzed by SPSS17 program. Results: the results of all data gathered from this study showed that the average error percentage of all inspected wrenches were 4.96 ± 3.77 % . the maximum average of error percentage were seen in Dio torque wrench with 10.46 ± 7.68 % and the minimum average was in Neobiotech torqur wrench with 2.97 ± 2.17 %. the average error of all 5 types of wrenches were 1.21 ± 1 N.Cm which the maximum of it belongs to Dio with 2.67 ± 0.95 N.Cm and the minimum of it were belongs to Osstem with 0.56 ± 0.46 N.Cm . in this study, we observed that the most torque error were belong to minimum torque force and by increasing the amount of torque force, the error percentage decrease. conclusion: the torque wrenches which were used in Tabriz dental offices in 58 the year of 1397 had good accuracy which all of them had a torque error less than 10% of target torque( except Dio with 10.46 ± 7.68 % error). The results of this study showed that the different types of wrenches had effect on torque wrech error, but the difference between torques were seen in wrenches of a same type. So we can conclude that the torque error not only affect by different types of wrenches, but also depends of others factors.