RESEARCH AND EDUCATION

Accuracy of mechanical torque-limiting devices for dental implants Emilie L’Homme-Langlois, DMD,a Burak Yilmaz, DDS, PhD,b Hua-Hong Chien, DDS, PhD,c and Edwin McGlumphy, DDS, MSd To provide optimal treatment ABSTRACT with implant restorations, it is Statement of problem. A common complication in implant dentistry is unintentional implant essential to understand screw screw loosening. The critical factor in the prevention of screw loosening is the delivery of the mechanics and why screws appropriate target torque value. Mechanical torque-limiting devices (MTLDs) are the most come loose. Multiple causes frequently recommended devices by the implant manufacturers to deliver the target torque value to the screw. Two types of MTLDs are available: friction-style and spring-style. Limited have been attributed to screw information is available regarding the influence of device type on the accuracy of MTLDs. loosening: inadequate torque delivery,1 embedment relaxaPurpose. The purpose of this study was to determine and compare the accuracy of spring-style and friction-style MTLDs. tion,1 inadequate prosthesis fit, poorly machined components, Material and methods. Five MTLDs from 6 different dental implant manufacturers (Astra Tech/ excessive loading, screw design, Dentsply, Zimmer Dental, Biohorizons, Biomet 3i, Straumann [ITI], and Nobel Biocare) (n=5 per and restoration design.2,3 When manufacturer) were selected to determine their accuracy in delivering target torque values preset by their manufacturers. All torque-limiting devices were new and there were 3 manufacturers for 2 parts are tightened together the friction-style and 3 manufacturers for the spring-style. The procedure of target torque by a screw, such as the abutmeasurement was performed 10 times for each device and a digital torque gauge (Chatillon ment and the implant or the Model DFS2-R-ND; Ametek) was used to record the measurements. Statistical analysis used crown and the implant, this nonparametric tests to determine the accuracy of the MTLDs in delivering target torque values unit is referred to as a screw and Bonferroni post hoc tests were used to assess pairwise comparisons. 2 joint. The forces attempting to Results. Median absolute difference between delivered torque values and target torque values of separate the parts of the screw friction-style and spring-style MTLDs were not significantly different (P>.05). Accuracy of Astra Tech joint are called joint separating and Zimmer Dental friction-style torque-limiting devices were significantly different than forces, and the forces keepBiohorizons torque-limiting devices (P

Accuracy of mechanical torque-limiting devices for dental implants.

A common complication in implant dentistry is unintentional implant screw loosening. The critical factor in the prevention of screw loosening is the d...
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