Effects of enamel and dentin thicknesses on the esthetic outcome and cytotoxicity of different tooth bleaching protocols

• Grant number: 14/07229-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date until: July 01, 2014
• End date until: March 31, 2016
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Carlos Alberto de Souza Costa
• Grantee: Carla Caroline de Oliveira Duque
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Currently, it was demonstrated that the intensity of adverse effects of tooth bleaching techniques on pulp-dentin complex is directly related to the group of teeth subjected to this procedure. In this way, the aim of this study is evaluate the effectiveness and cytotoxicity of experimental tooth bleaching protocols according to enamel and dentin thickness of dental substratum. Bovine discs, with enamel and dentin thickness similar to low mandibular incisors and upper premolars from human teeth, will be obtained. To analyze bleaching effectiveness, the discs will be stained and subjected to a 10% H2O2 gel, applied for 3x 15, 1x 15 and 1x 5 minutes onto enamel. As a positive control group, a 35% H2O2 gel will be applied for 3x 15 min. In the negative control group, no treatment will be performed. Bleaching sessions, within 24 hours interval, will be performed until a L=14.00 ±1 parameter be achieved, by using a spectrophotometer according to the CIE L*a*b* system. To evaluate the trans-enamel and trans-dentinal cytotoxicity, the discs will be adapted to artificial pulp chambers, and human pulp cells will be seeded on the dentin surface. Selected protocols, according to the color analysis assay, will be performed onto enamel/dentin discs. Cell viability (MTT assay) and cell morphology (SEM) will be analyzed immediatelly after bleaching and 72 hours thereafter, and also the oxidative stress (fluorescence), alkaline phosphatase (thymolphtalein assay) and mineralized nodule deposition (alizarin red). The quantification of H2O2 diffusion will also be assessed. Numeric data will be subjected to statistical analysis. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

DE OLIVEIRA DUQUE, C. C.; SOARES, D. G.; BASSO, F. G.; HEBLING, J.; DE SOUZA COSTA, C. A.. Influence of enamel/dentin thickness on the toxic and esthetic effects of experimental in-office bleaching protocols. CLINICAL ORAL INVESTIGATIONS, v. 21, n. 8, p. 2509-2520, NOV 2017. (14/07229-6)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

DUQUE, Carla Caroline de Oliveira. Influence of enamel and dentin thicknesses on the esthetic outcome and cytotoxicity of different tooth bleaching protocols. 2016. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara Araraquara.