The purpose of the present study was to investigate the effect of energy (sports) drinks on enamel hardness and shear bond strength of orthodontic brackets. Seventy maxillary first premolar teeth were divided into three groups. In Group I, the enamel hardness was measured with Vickers knoop hardness tester, after immersing the teeth in the distilled water (control) and energy drink for , one, two and four weeks. In group II, after 2 weeks of storage in the beverage and distilled water, the teeth were bonded with standard metal stainless steel brackets, using Concise composite resin, after which the SBS was immediately measured. Then the coefficient of correlation between hardness and SBS of group II was recorded. In group III, the teeth were stored in the beverage and water with bonded brackets, as in group I. The SBS was then measured. The 2 weeks and
4 weeks beverage groups showed the significantly lowest enamel hardness values with no difference between them. A positive correlation (r = 0.89) was found between enamel hardness and SBS.
The 4 weeks beverage storage showed the lowest SBS followed by 2 weeks storage, but the values were clinically acceptable. Thus, it was concluded that energy drinks significantly reduced enamel hardness and SBS, and this reduction was proportional to period of storage.