Influence of Light Curing Time on the Bond Strength of Orthodontic Brackets Using Different Light Curing Units – An In vitro Study

Abstract

Background: The bond strength of orthodontic brackets is crucial for successful orthodontic treatment. Light curing units (LCUs) play a significant role in this process, with varying light curing times potentially impacting bond strength. Materials and Methods: This in vitro study involved 60 extracted human premolars, randomly divided into three groups (n = 20) based on the type of LCU used: halogen, LED, and plasma arc. Each group was subdivided into two subgroups (n = 10) based on light-curing time (10 sec and 20 sec). The brackets were bonded using a standardized adhesive system. The bond strength was tested using a universal testing machine, and the data were statistically analyzed using ANOVA and post-hoc tests. Results: The results showed that the bond strength of orthodontic brackets varied significantly with different LUCs and curing times. The halogen LCU group demonstrated a mean bond strength of 12.5 MPa for 10 sec and 15.3 MPa for 20 sec. The LED LCU group showed a mean bond strength of 14.2 MPa for 10 sec and 16.8 MPa for 20 sec. The plasma arc LCU group exhibited a mean bond strength of 13.8 MPa for 10 sec and 17.1 MPa for 20 sec. Statistical analysis revealed that the LCU type and the light curing time significantly affected the bond strength (P < 0.05). Conclusion: The bond strength of orthodontic brackets is influenced by the type of LCU and the duration of light-curing.

Keywords

• bond strength
• curing time
• halogen light
• in vitro study
• led light
• light-curing units
• orthodontic brackets
• plasma arc light