브라켓 각도 변화에 따른 세라믹 브라켓의 마찰력 측정

Abstract

The purpose of this study was to measure and compare the level of frictional resistance generated from three currently used ceramic brackets; 1, Crystaline V^(®), Tomy International Inc., Tokyo, Japan; 2, Clarity^(®), 3M Unitek, Monrovia, CA, USA; 3, Inspire^(®), Ormco, Orange, CA, USA; with composite resin brackets, Spirit^(®), Ormco, Orange, CA, USA; and conventional stainless steel brackets Kosaka^(®), Tomy International Inc., Tokyo, Japan used as controls. In this experiment, the resistance to sliding was studied as a function of four angulations (0°, 5°, 10°, and 15°) using 2 different orthodontic wire alloys: stainless steel (stainless steel, SDS Ormco, Orange, CA, USA), and beta-titanium (TMA, SDS Ormco, Orange, CA, USA). After mounting the 22 mil brackets to the fixture and .019 × .025 wires ligated with elastic ligatures, the arch wires were slid through the brackets as 5 mm/min in the dry state at 34℃. Silica-insert ceramic brackets generated a significantly lower frictional force than did other ceramic brackets, similar to that of stainless steel brackets. Beta-titanium archwires had higher frictional resistance than did stainless steel, and all the brackets showed higher static and kinetic frictional force as the angulations increased. When the angulation exceeded 5°, the active configuration emerged and frictional force quickly increased by 2.5 to 4.5-fold. The order of frictional force of the different wire-bracket couples transposed as the angle increased. The silica-insert ceramic bracket is a valuable alternative to conventional stainless steel brackets for patients with esthetic demands.