Effectiveness of in-office bleaching with calcium polyphosphate submicroparticles on the physical properties of dental enamel and randomized clinical trial

• Grant number: 23/13376-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: May 01, 2025
• End date: September 30, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Debora Alves Nunes Leite Lima
• Grantee: Julliana Andrade da Silva
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Hydrogen peroxide (HP)-based whitening gels have evolved, and new formulations have been proposed to reduce damage to the dental structure. A previous formulation was developed containing submicroparticles of calcium polyphosphate (CaPP) with good properties as a remineralizing whitening agent and biological compatibility. CaPP is a compound synthesized by the research group and is promising, as it has biological activity comparable to hydroxyapatite, provides bioavailable calcium and phosphate ions to the surface of whitened enamel, and improves the physicochemical properties without affecting whitening efficacy. The use of this type of biopolymer is aimed at minimizing the adverse effects of dental whitening, such as tooth sensitivity, soft tissue irritation, and changes to the dental structure. For the development of this research, the first study will evaluate the use of HP gel (FGM, São Paulo) + CaPP in vitro by assessing the maintenance of color (deltaE, deltaE00, and WID) and its effects on dental surface morphology through surface microhardness (SMH) and cross-sectional microhardness (CSMH) analyses, roughness (Ra), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). Additionally, the deposition of CaPP on the whitened enamel will be analyzed using Raman spectroscopy (FT-Raman) and its effect on mineral loss of the whitened surface. In the second study, a randomized, double-blind clinical trial will evaluate the whitening effectiveness of the HP gel (FGM, São Paulo) + CaPP in vivo using a spectrophotometer (¿E, ¿E00, and ¿WID), while tooth sensitivity during and after whitening will be assessed using a visual analog scale (VAS). Complementarily, patient satisfaction with this new treatment will be evaluated. The in vivo whitened enamel surface will be qualitatively assessed using SEM, where impressions will be made with addition silicone, and models will be filled with epoxy resin and metalized with a gold alloy to obtain test specimens. Data will be subjected to descriptive and exploratory analysis, tested for normality (Shapiro-Wilks test) and homogeneity of variances (Levene test), followed by the appropriate statistical tests. All analyses will be performed using the SPSS statistical program (version 9.2, 2010), and the significance level will be set at 5%.