Nano‐hydroxyapatite‐induced remineralization of artificial white spot lesions after bleaching treatment with 10% carbamide peroxide
Amanda Cristina Brezolini da Freiria, Mariângela Ivette Guanipa Ortiz, Danielle Ferreira Souza de Sobral, Flávio Henrique Baggio Aguiar, Débora Alves Nunes Leite Lima
Abstract
Abstract Objective To assessed in vitro the effect of nanohydroxyapatite (n‐HA) to improve the aesthetic appearance and microhardness of white spot lesions (WSL) when associated with a low‐concentration bleaching agent (carbamide peroxide—CP10%). Material and methods Enamel/dentin specimens ( n = 60) of 5 × 5 × 2.2 mm were prepared, of these, 48 were submitted to pH‐cycling to create artificial WSL. Subsequently, these were allocated into five groups ( n = 12): n‐HA; n‐HA + CP10%; CP10%; WSL control (WSL C ); sound control (Sound). The color was assessed at baseline, pre‐treatment, and post‐treatment using a spectrophotometer, and the color (Δ E /Δ E 00 ) and whiteness index (ΔWID) alterations were determined. The enamel cross‐sectional microhardness (CSMH) was evaluated (post‐treatment) with a Knoop indenter, 25gf/5 s, 20–200 μm. The data was analyzed through generalized linear models ( α = 5%). Results Δ E and Δ E 00 were significantly higher for the bleached groups (n‐HA + CP10% and CP10%), and the n‐HA was higher than the WSL C group ( p < 0.05). ΔWID was significantly higher for the bleached groups ( p < 0.05). The CSMH values were significantly higher in the sound group than in the n‐HA, CP10%, and WSL C groups ( p < 0.05). The WSL C had lower microhardness than the n‐HA + CP10% and sound groups ( p < 0.05). Conclusion n‐HA is suitable to remineralize and recover the color of the WSL. However, its association with CP10% maintains the esthetical outcome while increasing its in‐depth remineralizing effect. Clinical significance Considering the aesthetic and functional repercussions of the WSL persistence, treatments that tend to improve its physical appearance and reinforce its weakened substructure in a non‐invasive way are ideal. For this associating low‐concentration, bleaching agents to the remineralizing treatments is promising to treat this type of lesions.