The present study was evaluated the effect of different light activation and thermocycling methods on the shear bond strength (SBS) and on the adhesive remnant index (ARI) of metal brackets bonded to feldspathic ceramic. Hundred metal brackets were bonded to 20 porcelain cylinders, divided into four groups (n=25) based on light activation and thermocycling processes. The cylinders were etched with 10% hydrofluoric acid for 60 s and coated with two layers of silane. The brackets were bonded with Transbond XT composite resin. Light activation in Groups 1 and 3 was performed during 3 s using the VALO Ortho Cordless appliance with irradiance 3,200 mW/cm2 and in Groups 2 and 4 for 40 s using Optilight Max appliance with irradiance 1,200 mW/cm². The samples were stored in deionized water at 37°C for 24 h and the samples from Groups 1 and 2 were submitted to the SBS test at a rate of 1 mm/min, whereas the samples from Groups 3 and 4 were submitted to 7,000 thermal cycles (5°/55°C) before to the SBS test. The data were assessed by two-way analysis of variance and by Tukey’s test (a=0.05). No significant difference was observed between SBS means in the different light activation devices used. The samples subjected to thermocycling revealed lower SBS values (p≤0.05). There was predominance of score 0 for ARI in all groups. Therefore, the different light activation methods did not interfere in SBS, but thermocycling reduced SBS.

Due to the need for new technologies that reduce the negative impact on the environment, the geopolymers, aluminosilicate-based materials, appear as a good alternative to Portland cement for having good mechanical properties, such as high initial strength. The objective of this work was to analyze the behavior of industrial geopolymer composites with the addition of jute fibers, according to the curing time of the material and the amount of fiber inserted, trying to identify if their use could bring benefits in the mechanical properties of the composite. Compression tests were made, and the results showed that the fibrous reinforced geopolymer composites have brought a good compatibility between fiber and matrix, showing a good mechanical behavior. The addition of the fibers allowed a greater ability of the composite to resist the loads after cracking, increasing its ductility. In addition to the increased deformation, there was also an increase in the compressive strength of the material.