Synthesis and characterization of strontium-substituted calcium phosphate particles and their effect on dentin mineralization

• Grant number: 18/10656-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2018
• End date: December 31, 2019
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Ana Paula Ramos
• Grantee: Tamires Maira Oliveira
• Host Institution: Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto (FFCLRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

This project aims to obtain hydroxyapatite (HAp) nanoparticles, in which Ca2 + ions will be replaced by Sr2 + in different molar ratios. Sr2 + can replace Ca2 + in the structure of HAp due to similarity of charge and size between these two ions. In addition, the presence of strontium is associated in vivo to the reabsorption control and increased bone formation. This ion is usually administrated to patients as strontium ranelate, a drug used for osteoporosis treatments. Problems such as hypersensitivity of teeth are present in a high percentage of the population. Furthermore, strontium of acetate has been already used in desensitizing dentifrice formulations, which promote mineralization of the dentin tubules. Thus, in this project the synthesis of HAp, main bone mineral component and dentin enamel replaced with Sr2 + is proposed aiming applications in the process of remineralization of dentin. Sr2+ -substituted HAp nanoparticles will be prepared from a mixture of CaCl2 and SrCl2 with Ca/Sr molar ratios of 0.1, 0.01 and 0.05 mixed with H3PO4. The pH will be increased by the quick addition of NH4OH and the precipitated will be filtered and washed with water. The particles will be characterized by means of FTIR, SEM, XRD and EDX. After characterization, the particles will be topically applied on demineralized dentin disks for the study on dentin remineralization in collaboration with Profª Alma Blácido, from the School of Dentistry of Ribeirão Preto-USP. It is expected at the end of the project to evaluate the influence of the concentration of Sr2 + on the HAp particles in the remineralization and obstruction of the dentinal tubules.