Incorporation of Calcium Polyphosphate Sub‐Microparticles in Commercial Toothpastes and Their Effects on Dental Enamel

Dental bleaching with 35% hydrogen peroxide (HP) can cause deleterious effects on the mineral content of enamel. In this regard, remineralizing submicroparticles of calcium polyphosphate (CaPP) have been investigated for their ability to deposit calcium ions into enamel's hydroxyapatite. Thus, this study aimed to evaluate the effects of commercial toothpastes with or without the addition of CaPP submicroparticles after in‐office bleaching treatment with 35% HP regarding color (Δ E , Δ E 00 and WI D ), microhardness (KHN), and surface roughness (Ra). Material and Methods Eighty bovine incisors were randomly divided into eight groups ( n = 10): NC (negative control); HP (Whiteness HP 35%—FGM); HP + CT12 (HP + Colgate Total 12); HP + CMP (HP + Colgate Máxima Proteção Anticáries); HP + CPA (HP + Colgate Sensitive Pró‐Alívio); HP + SRP (HP + Sensodyne Repair and Protect); HP + CT12 + CaPP (HP + Colgate Total 12 with 1% CaPP); HP + CMP + 1% CaPP (HP + Colgate Máxima Proteção Anticáries with 1% CaPP). All samples were subjected to the mechanical brushing protocol with 825 cycles and kept in artificial saliva with daily exchanges. Δ E , Δ E 00 , and WI D were analyzed through generalized linear models fitted for the group effect. KHN and Ra were analyzed through mixed linear models for repeated measures over time. All analysis was performed in R* software at the 5% significance level. Results Color variation (Δ E and Δ E 00 ) was higher in the HP + SRP group compared to NC and HP ( p < 0.0001). At T 1 , the NC group had a lower WI D than other groups ( p < 0.0001). Surface microhardness (KHN) analyses showed a significant group‐time interaction ( p = 0.04). At T1, the HP + CPA and HP + CT12 + 1% CaPP groups showed significantly higher median KHN values than the NC, HP, HP + CT12, and HP + CMP + 1% CaPP groups ( p < 0.05). Surface roughness (Ra) increased significantly after the first bleaching session, regardless of the experimental group ( p = 0.002). Conclusion The whitening effectiveness of 35% HP was maintained across the evaluated toothpaste formulations. Colgate Total 12 supplemented with 1% CaPP resulted in higher enamel microhardness than the corresponding formulation without CaPP, whereas no significant differences among the experimental groups were observed for surface roughness.