Influence of a catalytic primer on the aesthetic effectiveness, degradation kinetics and cytotoxicity of bleaching gels

• Grant number: 20/08882-6
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): April 01, 2021
• Effective date (End): February 28, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Carlos Alberto de Souza Costa
• Grantee: Marlon Ferreira Dias
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Chemical and enzymatic catalytic agents act directly on the degradation of hydrogen peroxide (H2O2), increasing the aesthetic efficacy and reducing the cytotoxicity caused by the conventional in-office dental bleaching widely employed. Thus, the objective of the present study is to assess the influence of an experimental polymeric catalytic primer (PCP) containing 10 mg/mL of manganese oxide (MnO) applied to enamel on the aesthetic efficacy, degradation kinetics and trans-enamel and trans-dentin cytotoxicity of bleaching gels containing 10%, 20% and 35% H2O2. For this purpose, enamel and dentin discs will be stained and then bleached with both products. A gel with 35% H2O2 applied for 45 min on the enamel or no enamel treatment will be used as controls. To determine the aesthetic efficacy, the discs will be stained and the enamel covered with the PCP, on which the bleaching gels will be applied (UV reflection spectrophotometer, CIE L *a*b* system). After this step, the rate of H2O2 degradation will be evaluated, as well as the production of hydroxyl radicals (OH*). To assess the trans-enamel and trans-dentin cytotoxicity, the discs will be adapted to artificial pulp chambers and the bleaching protocols will be performed. The extracts (culture medium + bleaching gel components diffused through the enamel/dentin discs) will be collected and applied on cultured odontoblast-like MDPC-23 cells, which will be evaluated concerning their viability (MTT) and morphology (MEV). The quantification of the total H2O2 capable of diffusing across the discs will be also determined (leuco-crystal violet/peroxidase). The numerical data obtained employing all laboratory protocols will be subjected to specific statistical analysis. (AU)

Academic Publications

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

DIAS, Marlon Ferreira. Influência de um primer catalisador sobre a eficácia estética, cinética de degradação e toxicidade de géis clareadores. 2022. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Odontologia. Araraquara Araraquara.