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

• Grant number: 23/14255-2
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2025
• End date: June 30, 2027
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Debora Alves Nunes Leite Lima
• Grantee: Debora Alves Nunes Leite Lima
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Associated researchers: Carolina Meneghin Barbosa ; Dr Klaus Rischka ; Julliana Andrade da Silva

Abstract

Commercial gel (Whiteness HP 35% and Whiteness HP35% Blue) will be added with remineralizing sub-microparticles of calcium polyphosphate (PPCa). PPCa is a promising compound and has biological activity comparable to hydroxyapatite, as it provides bioavailable calcium and phosphate ions to the surface of whitened enamel and improves physicochemical properties without affecting whitening efficacy and in order to reduce the adverse effects of tooth whitening. To carry out this research, the first study will evaluate the control group (without whitening treatment) with in-office whitening with gels: Whiteness HP 35%, Whiteness HP 35% + 0.5% PPCa, Whiteness HP 35% Blue and Whiteness HP 35% Blue + 0.5% PPCa will be evaluated in vitro to assess the conditions for maintaining color (¿E, ¿E00 and ¿WID), as well as its effects on the morphology of the tooth surface, using roughness (Ra), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS) analyses. In addition, the deposition of PPCa on bleached dental enamel will be analyzed using Raman spectroscopy (FT-Rman) and its effect on the mineral loss of the bleached surface using surface microhardness (SMH) and cross-sectional microhardness (CSMH) tests. The second study will be an in vivo randomized double-blind clinical study using Whiteness HP 35%, Whiteness HP 35% + 0.5% PPCa and Whiteness HP 35% Blue (FGM, São Paulo) gels. Whitening effectiveness will be analyzed using an Easy Shade spectrophotometer (¿E, ¿E00 and ¿WID), visual color evaluation before and after treatment (T1, T2, T3), using a Vita Bleached guide visual scale (¿SGU), while tooth sensitivity during and at the end of whitening (T1, T2, T3) will be determined using a visual analog scale (VAS). In addition, the degree of patient satisfaction with the treatments will be analyzed. The surface of bleached enamel in vivo will be evaluated qualitatively using SEM, in which it will be molded with addition silicone and models will be filled with epoxy resin and metallized with gold alloy to obtain specimens. The data will be subjected to descriptive and exploratory analysis, tested for data normality (Shapiro-Wilks test) and variance homogeneity (Levene test) and then the appropriate statistical tests will be chosen. All the analyses will be carried out using the SPSS statistical program (version 9.2, 2010) and the significance level adopted will be 5% (¿¿= 0.05). (AU)