摘要：OBJECTIVE: Adhesive systems used with brackets should provide sufficient bond strength to withstand forces duringmastication and orthodontic treatment. The purpose of this in vitro study was to assess the shear bond strength (SBS) and failure sites of different metallic and ceramic brackets by two different bonding systems. MATERIALS AND METHOD: Sixty-eight caries-free human mandibular premolars were randomly assigned to 4 groups of 17 each. Group 1 consisted of metallic brackets bonded with Transbond XT; Group 2 consisted of metallic brackets bonded with Clearfil S3 Bond Plus; ceramic brackets bonded with Transbond XT and Clearfil S3 Bond Plus composed Groups 3 and 4, respectively. A universal testing machine was used to determine the SBS, and the adhesive remaining after debonding was assessed using an adhesive remnant index (ARI). RESULTS: The bond strength of metallic brackets was significantly lower than the ceramic ones. Ceramic brackets bonded with Clearfil S3 Bond Plus declared the highest bond strength (p<0.001), revealing a mode of bond failure at the enamel-adhesive interface. However, the mode of failure for the conventional system was cohesive at the composite interface, showing a statistically significant difference between groups (p<0.05). CONCLUSION: Although all bonding systems provided adequate SBS values, Clearfil S3 Bond Plus requires a careful clinical application due to high bond strength and ARI scores. In relation to present findings, the conventional bonding system could be more suitable when ceramic brackets are bonded to enamel surface. Metal brackets can be bonded safely with both bonding systems.
