An Innovative Roll-on Bracket Design to Reduce Friction in Sliding Mechanics: A Finite Element Analysis

This study evaluated an innovative roll-on bracket, incorporating a ball-and-socket mechanism, for its biomechanical efficiency in reducing friction at the bracket-archwire interface during en masse retraction. The hypothesis was that selective placement would optimize sliding mechanics, yielding lower stress and deformation in dentoalveolar structures compared with conventional preadjusted edgewise brackets.

An in silico experimental study was performed using three-dimensional finite element analysis. Computed tomography scans of the maxillary dentition were used to construct anatomically accurate digital models. Roll-on and conventional MBT brackets were modeled and analyzed in ANSYS Workbench with validated material properties. Orthodontic forces of 1 N, 2 N, and 3 N were applied under three configurations: roll-on brackets on anterior teeth, roll-on brackets on canines and premolars, and conventional brackets on anterior teeth. Outcomes included stress at the bracket-archwire interface, periodontal ligament (PDL), alveolar bone, and dentition, as well as deformation patterns.

Roll-on brackets on anterior teeth produced higher anterior stress and deformation but reduced posterior load. Selective placement on canines and premolars significantly lowered anterior stress and deformation while optimizing overall stress distribution, though with increased posterior anchorage demands. Stress and deformation patterns were directly proportional to force magnitude.

The roll-on bracket can modulate orthodontic biomechanics, with effectiveness influenced by placement within the arch. Strategic application may enhance force efficiency and reduce adverse tissue effects, though clinical validation is required.