Force decay and deformation of orthodontic elastomeric ligatures

摘要: This study evaluated commercially available molded gray elastomeric ligatures from seven companies for force decay, dimensional change, and the relationship between ligature dimension force. The initial wall thickness, inside diameter, outside levels of each were measured. Three four test groups stretched over stainless steel dowels with a circumference approximating that large orthodontic twin bracket. Test group 1 was kept at room temperature humidity 28 days 2 in synthetic saliva bath 37 degrees C, pH 6.84 days. residual forces changes third placed 6.84, recorded initial, 24 hours, 7 days, 14 fourth unstretched samples to evaluate due solely moisture sorption. results simulated oral environment revealed following: (1) Moisture heat had pronounced effect on decay permanent deformation, (2) positive correlation existed thickness force, (3) negative diameter (4) weak (5) greatest loss occurred first hours pattern similar all tested, (6) absorbed range 0.060% 3.15%. tested appear be suitable use during aligning leveling. However, rapid deformation these products may preclude their rotational torque corrections.