Comparison of Light-Curing Time With the Use of Different Led Intensities in the Bonding of Orthodontic Brackets

Objective: To compare the shear bond strength of metallic brackets after orthodontic bonding using conventional and high-intensity light curing devices. Methods: Eighty bovine central incisors were randomly divided into four groups according to curing time and LED devices: G1- Use of conventional LED LCU curing for 20 seconds (Emitter D - Wireless, Schuster, Brazil); G2- High Intensity LED LCU for 3 seconds (Valo Cordless, Ultradent Products, USA); G3- High Intensity LED LCU for 3 seconds (Flash Max P4 Ortho Pro, CMS Dental A / S, Denmark) and G4 - High Intensity LED LCU for 3 seconds (LEDX-T 2400 Orthometric, Brazil). Twenty-four hours after bonding, brackets were subjected to a universal testing machine with a shear bond strength (SBS) test. The Enamel surface was visually evaluated with the Adhesive Remnant Index (ARI). The one-way ANOVA was performed to compare the SBS between the different light-curing devices. The adhesive remnant index (ARI) was compared with the chi-square test. Results: There were no significant differences between the groups (p = 0.767). The analysis of the adhesive remnant index also showed no statistically significant differences between the groups. Conclusion: There was no difference in the shear bond strength and ARI index with a curing time of 3 seconds in high-intensity LCU and 20 seconds in conventional LCU.