Color alteration, hydrogen peroxide diffusion, and cytotoxicity caused by in-office bleaching protocols

Author(s)

Amaral Gonzaga de Almeida, Leticia Cunha ^[1] ; Soares, Diana Gabriela ^[2] ; Gallinari, Marjorie Oliveira ^[1] ; de Souza Costa, Carlos Alberto ^[3] ; dos Santos, Paulo Henrique ^[2] ; Fraga Briso, Andre Luiz ^[1]

Affiliation

^[1] Univ Estadual Paulista UNESP, Aracatuba Sch Dent, Dept Restorat Dent, BR-14801903 Aracatuba, SP - Brazil

^[2] Univ Estadual Paulista UNESP, Aracatuba Sch Dent, Dept Dent Mat & Prosthodont, BR-14801903 Aracatuba, SP - Brazil

^[3] Univ Estadual Paulista UNESP, Aracatuba Sch Dent, Dept Physiol & Pathol, BR-14801903 Aracatuba, SP - Brazil

• Document type: Journal article
• Source: CLINICAL ORAL INVESTIGATIONS; v. 19, n. 3, p. 673-680, APR 2015.
• Web of Science Citations: 11

Abstract

This study evaluated the color alteration, cytotoxicity, and hydrogen peroxide (HP) diffusion associated with different in-office bleaching protocols. Bovine enamel/dentin disks were subjected to three bleaching sessions with 35 % HP (three 15-min applications), 35 % HP (one 45-min application), or 20 % HP (one 45-min application). The control group was not bleached. Before bleaching, the disks were adapted to artificial pulp chambers positioned in compartments containing 1 ml of acetate buffer or medium, so that the dentin remained in contact with these substances. Immediately after bleaching, the HP that diffused through the disks was stabilized by acetate buffer and was quantified (two-way repeated measures ANOVA/Fisher's protected least significant difference (PLSD) test; alpha = 5 %). Cells of mouse dental papilla cell-23 (MDPC-23) were incubated in this culture media for 1 h, followed by analysis of cellular metabolism (methyl tetrazolium assay) (one-way ANOVA/Tukey test; alpha = 5 %) and morphology (scanning electron microscopy). The specimen color alteration (Delta E) was analyzed by reflection spectrophotometry (two-way repeated measures ANOVA/Fisher's PLSD test; alpha = 5 %). All protocols showed equal effectiveness at the end of the treatment. HP diffusion was significantly higher in the groups bleached with 35 % HP. Reapplication of 35 % HP resulted in increased diffusion only in the first session; however, the decrease in cell metabolism was similar for all studied protocols. Despite greater peroxide diffusion in the groups treated with 35 % HP, all protocols showed the same effectiveness and were cytotoxic to MDPC-23 cells. Bleaching protocols using high HP concentrations should be avoided because they exert aggressive actions on odontoblast-like cells. (AU)

• FAPESP's process: 10/17637-3 - Color alteration and trans-enamel, and trans-dentinal H2O2 penetration and cytotoxicity in bleached teeth
• Grantee: André Luiz Fraga Briso
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/10378-2 - Color alteration and trans-enamel,and trans-dentinal H2O2 penetration and cytotoxicity in bleached teeth
• Grantee: Letícia Cunha Amaral Gonzaga de Almeida
• Support Opportunities: Scholarships in Brazil - Doctorate