Effect of whitening gels formulated with calcium polyphosphate on color change and mineral content of dental enamel

• Grant number: 22/15739-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2023
• End date: September 30, 2024
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Alberto Carlos Botazzo Delbem
• Grantee: Lara Oliveira Ribeiro Urzedo
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The objective of this project will be to synthesize and characterize cyclotriphosphate (sodium trimetaphosphate, "TMP") with total replacement of sodium by calcium (Ca2+) (CaTMP); and to analyze in vitro the effect of its incorporation in bleaching formulations based on hydrogen peroxide (H2O2) at 17.5% and 35% on mineralized tissues. Cyclotriphosphate containing calcium will be synthesized using a column for chromatography and addition of supernatant solution containing calcium hydroxide and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-rays (EDX). The bleaching gels will be applied on bovine tooth discs, according to the groups: 1) Negative control - deionized water; 2) Whitening gel containing 35% H2O2 (Positive control); 3) Whitening gel containing 35% H2O2 + 1% CaTMP; 4) Whitening gel containing 17.5% H2O2; 5) Whitening gel containing 17.5% H2O2 + 1% CaTMP. The gels will be applied only once, during 3 sessions of 40 minutes/session, every 7 days, totaling 21 days. Then, the color change will be evaluated by quantified reflection spectrophotometry (”E* , ”WID and ”E00), and the enamel mineral content by computed microtomography (gHAp×cm- 3). Variables with normal and homogeneous distribution will be submitted to analysis of variance (p<0.05). Otherwise, they will be submitted to the Kruskal-Wallis test (p<0.05). The multiple comparison test will be Student-Newman-Keuls.