Bleaching potential, effects on dental enamel and cytotoxicity of phthalimidoperoxycaproic acid combined with violet LED.

• Grant number: 23/07173-0
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): May 01, 2024
• Effective date (End): November 30, 2025
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Vanessa Cavalli Gobbo
• Grantee: Samuel da Silva Palandi
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

A new product based on phthalimidoperoxycaproic acid (PAP) claims to be able to promote tooth whitening without causing changes in the mineral concentration of enamel, or changes in soft tissues, and may promote greater potential for color change when subjected to Violet LED light. Therefore, the objective of this study will be to evaluate the effectiveness of PAP associated or not with violet LED, in changing the color, microhardness and morphology of dental enamel and cytotoxicity for pulp and gingival cells. Bovine incisor enamel discs will be stained with buffered black tea and treated with (n=12): (PAP) phthalimidoperoxycaproic acid; (PH40) 40% hydrogen peroxide; (PH10) 10% hydrogen peroxide. The groups will or will not be submitted to violet light (MMO and VIO), and the control (CON, without bleaching) will remain in artificial saliva during the experiment. The gels will be applied as instructed by the manufacturers and in phase 1 the color change (”E00) and whitening index (”WID) will be determined, measured in a digital spectrophotometer, and the % loss of surface hardness (%PDS) with indenter Knoop. Data will be collected after pigmentation (T0), after 24 hours (T1) and after 14 days of bleaching treatment (T2). In phase 2, the cytotoxicity of the gels tested in odontoblastic cells in an artificial pulp chamber (CPA) will be determined using the MTT test, oxidative stress analysis, quantification of PH in extracts, free radical production, live/dead fluorescence and morphology cell. In phase 3, the cytotoxicity of the gels on gingival fibroblasts will be determined by means of the cell viability test (MTT), analysis of the gingival fibroblast secretome and cell morphology. In phase 4, the characterization of the irradiance and power of the LED devices (MMO and VIO) will be carried out and the pH of the whitening gels will be measured. Appropriate statistical analyzes will be performed considering a significance level of 5%.