Introduction: This study compared the shear bond strength of metal orthodontic brackets adhered to different restorative materials under erosive conditions. Also, the resistance of these restorations to secondary caries was evaluated. Methods:60 extracted premolars were used,1 operator prepared class V cavities. 2 groups of 30 samples were randomly created according to restorative material: Group (I): bulk fill resin composite material and Group (II): resin-modified glass ionomer restorative material . Metal brackets were bonded to restorative surfaces using flowable composite. All specimens were stored in distilled water for 1 day at 37°C. Each Group was subdivided into 3 subgroups according to the test performed: 10 samples for the shear bond strength test using a Universal testing machine at baseline, 10 samples for SBS testing after thermal cycles (1000 cycles,5-55°C) followed by immersion for 72 hours in demineralizing solution and 10 specimens were assessed for caries detection around restorations using DIAGNOdent pen at baseline and after both thermocycling and immersion in demineralizing solution. Data were statistically analyzed using Microsoft Excel ® 2016, Statistical Package for Social Science (SPSS) ® Ver. 24 and Minitab ® statistical software Ver. 16. Results: For SBS results, there was a significant decrease for both Gp I and Gp II after thermo-erosive cycles with insignificant difference between them. For secondary caries, Gp I had significantly showed lower risk than GP II after all challenges. Conclusion:Bulk fill restorations have been shown to provide safer outcomes for restoring class V lesions in patients undergoing orthodontic treatment.