VIABILITY AND STRESS OF PULP CELLS EXPOSED TO EXTRACTS OBTAINED AFTER APPLICATION OF PHARMACEUTICAL FORMULATIONS TO THE ENAMEL AND TOOTH BLEACHING
Tooth Bleaching; Hydrogen Peroxide; Tooth Remineralization; Cell Survival; Oxidative Stress; Nanotechnology.
Introduction: Hydrogen peroxide tooth bleaching can cause cytotoxicity, inflammation, and pain. Some alternatives, such as remineralizing, analgesic, and anti-inflammatory agents, are being studied to control bleaching-induced sensitivity. One proposal would combine them to develop nanostructured pharmaceutical formulations that diffuse into dental tissues, maintain cell viability, and decrease oxidative stress caused by hydrogen peroxide. Objective: To analyze the viability and stress of pulp stem cells exposed to extracts obtained after applying nanostructured pharmaceutical formulations to the enamel and tooth whitening in bovine teeth. Methodology: Initially, 154 samples of bovine incisors will be prepared and divided into 22 experimental groups (n=7) for sample size calculation. The samples will have a pulp chamber filled with ultrapure water, which is necessary for the experimental procedures. Eight groups will have the specimens bleached with 35% hydrogen peroxide. They will have applications of nanogels before and after bleaching, and 8 groups will have the samples not bleached, using a placebo, and will follow the same nanogel application protocol. The extract obtained by passing substances through the specimens in each experimental group will be collected from the pulp chamber. To simulate a total passage of drugs through the specimens, 6 groups will be formed by combining the extract obtained from only bleached specimens with the addition of nanogels to the extract. After obtaining and collecting the extracts, dental pulp stem cells will be exposed to the extracts, and viability, cell death, and oxidative stress analyses will be performed. The one-way parametric ANOVA test (<0.05) will be used for data analysis. Expected results: The developed nanogels are expected to maintain cell viability and reduce cellular stress caused by hydrogen peroxide, suggesting the efficacy of the nanogels. This may pave the way for future studies to confirm this efficacy in reducing or eliminating sensitivity induced by in-office whitening.