Nano-hydroxyapatite-induced remineralization of artificial white spot lesions after bleaching treatment with 10% carbamide peroxide

Author(s)

da Freiria, Amanda Cristina Brezolini ; Ortiz, Mariangela Ivette Guanipa ; de Sobral, Danielle Ferreira Souza ; Aguiar, Flavio Henrique Baggio ; Lima, Debora Alves Nunes Leite

• Document type: Journal article
• Source: Journal of Esthetic and Restorative Dentistry; v. 34, n. 8, p. 10-pg., 2022-10-07.

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 x 5 x 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 (WSLC); sound control (Sound). The color was assessed at baseline, pre-treatment, and post-treatment using a spectrophotometer, and the color (Delta E/Delta E-00) and whiteness index (Delta WID) alterations were determined. The enamel cross-sectional microhardness (CSMH) was evaluated (post-treatment) with a Knoop indenter, 25gf/5 s, 20-200 mu m. The data was analyzed through generalized linear models (alpha = 5%). Results Delta E and Delta E-00 were significantly higher for the bleached groups (n-HA + CP10% and CP10%), and the n-HA was higher than the WSLC group (p < 0.05). Delta WID 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 WSLC groups (p < 0.05). The WSLC 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. (AU)

• FAPESP's process: 19/20272-1 - Development of a hydrogen peroxide bleaching agent with the addition of calcium polyphosphate nanoparticles and its effect on the whitening and mineralization of dental enamel
• Grantee: Mariangela Ivette Guanipa Ortiz
• Support Opportunities: Scholarships in Brazil - Doctorate