Development and application of a TiF4-loaded polymeric primer for in-office dental bleaching

• Grant number: 22/08283-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: November 01, 2022
• End date: February 29, 2024
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Carlos Alberto de Souza Costa
• Grantee: Victória Peruchi
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

The objective of this study will be to develop an innovative polymeric primer (PP) containing different concentrations of titanium tetrafluoride (TiF4) catalyst, which can be used for in-office dental bleaching, aiming to increase aesthetic efficacy, prevent morphological changes in dental enamel and to reduce the cytotoxicity of the therapy. For this, enamel/dentin discs will be stained and then subjected to bleaching for 45 minutes (1 session) with a bleaching gel containing 35% H2O2. The gel will be applied on enamel previously coated with a PP containing different concentrations of TiF4 (2 mg/mL, 6 mg/mL or 10 mg/mL). As a positive control, the same gel will be applied directly on the enamel, and in the negative control, no treatment will be performed. To determine the best concentration of TiF4 present in P, a screening of the bleaching efficacy will be initially performed using a UV-reflection spectrophotometer (CIE L*a*b* System). The same treatments will be performed to evaluate the possible morphological alteration of the dental enamel structure (Microhardness, Scanning Electron Microscopy and Energy Dispersive Spectrometry). To evaluate the trans-dentinal cytotoxicity, enamel/dentin discs will be adapted in artificial pulp chambers. After completing the bleaching treatments, the extracts (culture medium + diffusion components of bleaching gels) will be obtained and applied on odontoblast-like MDPC-23 cells, which will be evaluated for viability (MTT) and morphology (SEM). The quantification of the total H2O2 capable of spreading through the discs will also be determined (Violet leuko-crystal/Peroxidase). After this step, the degradation rate of residual H2O2 will be evaluated, as well as the production of hydroxyl radicals (OH*). The numerical data obtained through the application of laboratory protocols will be submitted to specific statistical analysis.