Biomimetic Effect of Nano-Hydroxyapatite in Demineralized Enamel before Orthodontic Bonding of Brackets and Attachments: Visual, Adhesion Strength, and Hardness in In Vitro Tests

Figure 2

Percentage of visual hypomineralized areas for control and experimental groups (mean and standard deviation). Before acid treatment (t0); after acid treatment (t1); 30 days after acid treatment (t2); 60 days after acid treatment (t3); 90 days after acid treatment (t4).