Background: With the increasing importance of new-generation universal bonds, understanding how to enhance their bond strength to enamel and dentin is crucial. The aim of this study was to investigate the effect of activation on dentine bond strength in universal bonding with two etching and non-etching
methods.
Materials and methods: In this experimental laboratory study, 96 intact premolars extracted as part of orthodontic treatment within the last 6 months were selected. The samples were divided into 2Etching and non-Etching groups. Each group was further divided into three subgroups of 16 samples: according to the method used to apply the bonding agent. After bonding, the composite cylinders were connected to the conditioning surface, and then the samples Instron machine. The data were analyzed by two-way analysis of variance and Tukey's post hoc test (α= 0.05).
Results: Among the six studied groups, the highest bond strength was observed in the non-etched group where universal bonding was applied using a sonic device. Conversely, the lowest bond strength was found in the etched group, where universal bonding was applied through rubbing. The mean dentine bond strength using the non-etching method increased significantly compared to the etching method (p < 0.001). As for the effect of the activation method on dentine bond strength, the mean bond strength in the etching method did not differ significantly among the three activation methods (p > 0.05). However, in the non- etching method, the mean dentine bond strength was strongest in the sonic group, followed by the non- activated group and the rubbing group (p = 0.05).
Conclusion: Using a sonic device and avoiding dentin acid etching before bonding can enhance dentine
bond strength in universal bonding