Based on the optical changes induced in eroded tissue by the lesions, in 2015 Koshoji "et al." also demonstrated in a novel method that using laser speckle images (LSI) it is possible to acquire information on the microstructure of the enamel and detect minimal changes, such as early non-carious lesions. To produce the erosion, the samples were divided into four groups and immersed in 30 mL of a cola-based beverage (pH approximately 2.5) at room temperature. A representative image of the samples under white and laser illumination shows that although there are visible stains in the left portion of each sample due to the dye from the cola beverage, structural changes are difficult to assess with the naked eye.