“…The sample size considered the previous literature 9,13 , significance level of 0.05, and test power of 0.80. Therefore, the final sample included 72 polycrystalline ceramic brackets (Iceram, Orthometric, Marília, São Paulo, Brazil; Batch 037268001) of upper right central incisors, which were divided into six groups (n=12) according to dye solution: G1 -distilled water (control group, Asfer, Indústria Química, São Caetano do Sul, SP, Brazil; Batch 274); G2 -0.12% chlorhexidine (Periogard, Colgate; Batch 7125BR121A); G3 -instant coffee (Nescafé, Nestlé, São Paulo, Brazil; Batch 80301210); G4 -red wine (Reservado, Carbenet Sauvignon 12.5% alcohol volume, Concha y Toro/ Santiago do Chile; Batch: 1110716); G5 -chlorhexidine and coffee; G6 -chlorhexidine and wine, as Figure 1 shows.…”