Evaluation of the Efficiency of Surface-Treated Mini Screws in Space Closure Mechanics: A Three-Dimensional Perspective Study

Abstract

A total of 10 patients with excessively protruded upper anterior teeth were subjected to orthodontic treatment and subsequently divided into two equal groups: one group received sandblasted and acid-etched miniscrews, while the other group used titanium miniscrews. The miniscrews (MSs) with surface treatment and the smooth ones were placed between the maxillary second premolar and first molar at the mucogingival junction on both sides of each patient. A closed coil spring was extended from the head of the miniscrews to a hook secured onto the main arch wire between the maxillary lateral incisor and canine on both sides, applying a force of 250 g per side for the en-masse retraction of the upper anterior teeth. Cone Beam Computed Tomography (CBCT) scans were performed twice: prior to force application (CBCT 1) and six months later (CBCT 2). To assess the displacement of the mini-screws, the distances from the mini-screw head (HMS) and tail (TMS) to the coronal, sagittal, and axial planes were measured at both CBCT time points. Results: There was a statistically significant difference in HMS displacement between titanium and Sand blasted and Acid etched groups in all three- dimensions (coronal, sagittal, axial). While no statically significant different was found in TMS displacement between titanium and Sand blasted and Acid etched groups in all three- dimensions (coronal, sagittal, axial). Conclusions: Miniscrews were displaced in the direction of orthodontic loading. The displacement was experienced in the movement of the head more than the tail of the miniscrews.