The Tip and Torque adjustable bracket as a new concept in design: An in vitro study

Abstract

Objectives: To test a new concept in bracket design - the tip and torque adjustable bracket (TTAB) - to identify its integral ability to change both tip and torque. Materials and Methods: The newly designed TTAB underwent independent testing using the orthodontic measurement and simulation system. The TTAB incorporated Roth tip and torque prescription values, with the unique quality of the bracket to enhance or reduce the innate prescribed values of tip (by either +10°C or -10°C) and torque (by either +7.5°C or -7.5°C). The TTAB was tested using both the incorporated standard Roth prescription on the rate of canine retraction (sliding mechanics), using 0.018-inch stainless-steel (SS) arch wire, and with alteration of tip values (-10°C and +10°C). Similarly, frictional measurements and torque evaluations using 0.019 × 0.025- inch SS arch wire were undertaken with the standard prescription and altered torque (+7.5°C and -7.5°C). In addition, a number of control investigations were performed. Differences were analyzed using analysis of variance. Results: The rate of observed tooth movement for the TTAB with its prescribed baseline values was comparable to that of the control brackets. Importantly, the alteration of TTAB tip to -10°C and +108 significantly (P < .001) increased and reduced, respectively, the rates of canine retraction. In the alteration of torque, at +7.5°C and -7.5°C, the bracket delivered a moment of +9.3 (2.8) Nmm and -11.9 (3.8) Nmm, respectively, to the lateral incisor (P < .001). Conclusions: This in vitro study demonstrates a new concept in preadjusted edgewise bracket design, offering adjustable tip and torque, with the potential for expanded clinical scope.