title: At-Home Bleaching: Color Alteration, Hydrogen Peroxide Diffusion and Cytotoxicity.
abstract: This study evaluated the color change, cytotoxicity and hydrogen peroxide (HP) diffusion caused by different home bleaching protocols: 10% carbamide peroxide (CP) for 3 or 1.5 h, 6% hydrogen peroxide for 1.5 h or 45 min. To quantify the peroxide penetration, disks of bovine teeth were placed in artificial pulp chambers (APCs) containing acetate buffer, which was collected for evaluation in a spectrophotometer. For analysis of cytotoxicity, specimens were adapted in APCs containing culture medium, which subsequently was applied on MDPC-23 odontoblast-like cells for 1 h. Cellular metabolism was evaluated by methyl tetrazolium (MTT) assay and the color change of the specimens was analyzed using the CIE L * a * b * system. The data were submitted to ANOVA and Fisher test (α=5%). The treatment with 10% CP for 3 h was the most effective, and 6% HP for 45 min produced the lowest color change. The groups 10% CP for 1.5 h and 6% HP for 45 min had the lowest trans-enamel dentinal HP penetration, and the 6% HP for 1.5 h had the highest. None of the protocols affected cellular metabolism and morphology. In conclusion, reduced peroxide exposure time reduced the bleaching result; higher HP diffusion did not mean higher effectiveness.
authors: Department of Restorative Dentistry, Araçatuba School of Dentistry, Univ Estadual Paulista, Araçatuba, SP, BR.
authors: Leticia Cunha Amaral Gonzaga
authors: LC
authors: de Almeida
authors: Department of Physiology and Pathology, Araraquara School of Dentistry, Univ Estadual Paulista, Araraquara, SP, BR.
authors: Diana Gabriela
authors: DG
authors: Soares
authors: Department of Restorative Dentistry, Araçatuba School of Dentistry, Univ Estadual Paulista, Araçatuba, SP, BR.
authors: Fernanda Almeida
authors: FA
authors: Azevedo
authors: Department of Restorative Dentistry, Araçatuba School of Dentistry, Univ Estadual Paulista, Araçatuba, SP, BR.
authors: Marjorie de Oliveira
authors: Mde O
authors: Gallinari
authors: Department of Physiology and Pathology, Araraquara School of Dentistry, Univ Estadual Paulista, Araraquara, SP, BR.
authors: Carlos Alberto de Souza
authors: CA
authors: Costa
authors: Department of Dental Materials and Prosthodontics, Araçatuba School of Dentistry, Univ Estadual Paulista, Araçatuba, SP, BR.
authors: Paulo Henrique
authors: PH
authors: dos Santos
authors: Department of Restorative Dentistry, Araçatuba School of Dentistry, Univ Estadual Paulista, Araçatuba, SP, BR.
authors: André Luiz Fraga
authors: AL
authors: Briso
mesh_terms: D002460:Cell Line; D003116:Color; D003470:Culture Media; D004058:Diffusion; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013053:Spectrophotometry; D014073:Tooth Bleaching / Q000379:methods*
chemical_list: D003470:Culture Media; D006861:Hydrogen Peroxide