Development of an innovative strategy for in-office tooth bleaching: aesthetic effectivity and biocompatibility associated with reduced clinical time

• Grant number: 20/09095-8
• Support type: Regular Research Grants
• Duration: December 01, 2020 - November 30, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal researcher: Carlos Alberto de Souza Costa
• Grantee: Carlos Alberto de Souza Costa
• Home Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Assoc. researchers: Diana Gabriela Soares dos Passos ; Josimeri Hebling Costa

Abstract

Despite the excellent aesthetic outcome obtained using the in-office dental bleaching therapy, which uses gels with high concentrations of hydrogen peroxide (H2O2), this professional treatment may cause irreversible pulp damage and tooth sensitivity. Thus, new dental bleaching protocols based on the use of gels with low concentrations of H2O2 or shortened periods of gels application on enamel have been assessed. However, these new tooth bleaching protocols have negatively influenced the aesthetic outcome or request a number of bleaching sessions, turning impracticable their clinical application. Therefore, innovative in-office tooth bleaching strategies capable of getting fast and appropriate aesthetic results with no pulp damage or post-treatment sensitivity are needed. The aim of the present study is to apply the knowledges of Biomaterials Engineering and Advanced Oxidative Processes to develop a Universal Protective Barrier (UPB), that will recover dental enamel before applying the bleaching gel which will be irradiated or not with violet LED. In Phase 1, standardized enamel/dentin discs will be obtained, stained and distributed into groups; these discs will be used in the following phases of this project. In Phase 2, a Protective Polymeric Tape (PPT) and a Catalytic Primer (CP) will be developed to co-work as a double barrier (UPB) to improve the in-office tooth bleaching. In Phase 3, after covering the enamel with the UPB, the bleaching gel with 35% H2O2 will be applied on it for 45 min. and the aesthetic outcome as well as and trans-enamel and trans-dentinal toxicity on the odontoblast-like MDPC-23 cells will be assessed. In Phase 4, after covering the enamel with the UPB, the bleaching gel with 35% H2O2 will be applied for 15, 30 and 45 min. on it and irradiated with violet LED. Then, the aesthetic outcome as well as and trans-enamel and trans-dentinal toxicity on the MDPC-23 cells will be assessed. The shorter tooth bleaching time strategy that provides an aesthetic outcome like the traditional in-office tooth bleaching therapy will be selected. In Phase 5, the tooth bleaching strategy selected in Phase 4 will be assessed concerning its cytocompatibility using a 3D model of human dental pulp cells. All data obtained in this in vitro study will be submitted to specific statistical analysis. (AU)