Does the addition of bioglass 45S5 to a bleaching gel influence enamel color, roughness, and mineral content?

Abstract Objective To evaluate color change, surface roughness, microhardness, and morphology of enamel submitted to bleaching with 35% hydrogen peroxide (HP) gels associated with different concentrations of bioglass 45S5 (BG).Methods Enamel blocks (n = 10) were submitted to a positive control (PC): 35% HP bleaching; HP_BG: HP associated with a gel containing BG at concentrations of 0, 2.5, 5, 7.5, 10 wt% and negative control (NC), no treatment in 3 sessions of 40 min each and 7 days apart. The blocks were kept in artificial saliva up to 14 days after bleaching. Color change (ΔE00), color parameters (ΔL, Δa, Δb), roughness average (ΔRa), and surface microhardness were evaluated at baseline (T0), after 24h (T1), and 14 days elapsed from bleaching treatment (T2). The percentage of surface hardness loss (%SHL) was calculated and the enamel was characterized at T2 by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Data were subjected to ANOVA and Tukey test (α = 0.05).Results No differences in ΔE00 and Δb were observed among HP-containing groups, regardless of the BG concentration (p > 0.05). Additionally, no differences were noted in ΔRa, ΔL, and Δa among the groups (p > 0.05). However, BG incorporation into the bleaching gels prevented enamel mineral loss in comparison to PC immediately after bleaching treatment (T1, p < 0.05). At T2, 10% BG was the only group to keep enamel mineral content (p < 0.05). Conclusion: The addition of BG did not affect the HP bleaching efficacy and the incorporation of 10% BG into the HP bleaching agent exhibited a positive remineralizing effect.Clinical Relevance: It was found with BG has the potential to reverse the harmful effects on the dental surface during the bleaching protocol.