فهرست نشریات علمی دسترسی آزاد ایران

Orthodontic brackets especially those made from alumina-based ceramics have become more popular due to their superior aesthetics and biocompatibility. However, their brittleness remains a drawback, as they are more likely to chip or break during treatment compared to metal brackets. The objective of this study is to analyze the mechanical deformation of ceramic brackets under varying archwire deflection and oral temperature using finite element analysis. Aesthetic Roth prescription of polycrystalline ceramic bracket with “0.022” inches slot and rectangular NiTi archwire were used. A three-dimensional finite element model was developed to simulate a modified 3-point bending test at magnitudes of deflection ranges from 1 to 6 mm. Temperature ranges used was from 26 °C to 56 °C which represented a range of typical oral temperature variations. Stress and strain were recorded at specific reference points within bracket slot at both loading and unloading cycle. The simulation results reveal that deformation in ceramic bracket slots was consistently concentrated at the corner regions across all three ceramic brackets. Both increasing wire deflection and temperature significantly elevated stress levels, often surpassing the fracture strength of the brackets, particularly during the loading cycle. The maximum stress observed during loading was 411.02 MPa at 56 °C for a 6 mm deflection case. Although the unloading cycle exhibited lower stress levels, deflections exceeding 2 mm still posed failure risks, with a maximum recorded stress of 220.19 MPa at 56 °C for a 6 mm deflection case. These findings highlight the critical influence of wire deflection and temperature on the mechanical deformation of ceramic brackets. These findings underscore the critical role of archwire deflection and oral temperature in managing stress distribution and preventing fracture in ceramic brackets. Clinicians should carefully evaluate bracket materials, particularly in cases involving substantial wire activation or elevated oral temperatures and advise patients on temperature-sensitive dietary habits to mitigate the risk of premature bracket failure.