In vivo analysis of the biological response, local and systemic migration of chemical elements released from calcium silicate-based materials in contact with connective and bone tissue

• Grant number: 23/09478-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2023
• Status: Discontinued
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marina Angélica Marciano da Silva
• Grantee: Brenda Fornazaro Moraes
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Associated research grant: 22/03093-9 - Local and systemic effects of radiopacifiers from reparative dental materials, AP.PNGP.PI
• Associated scholarship(s): 24/07583-6 - Renal cytotoxicity of endodontic materials' leachates, BE.EP.MS

Abstract

The aim of this study is to evaluate the migration and local accumulation of radiopacifiers released by calcium silicate-based materials after contact with connective and bone tissues. A total of 110 animals will be divided into 6 experimental groups, according to both the materials to be implanted and its application site. The following materials will be implanted in the subcutaneous tissue and bone, corresponding to a type of radiopacifier: Gray-MTAFlow (bismuth oxide), White MTAFlow (tantalum oxide), MTA Repair HP (calcium tungstate), Biodentine (zirconium oxide), tricalcium silicate (positive control - no radiopacifier) and a negative control group without any procedure. Two 2x4 mm samples, of the same material, will be implanted subcutaneously and, in cavities with the same dimensions, in the femur of each animal. The materials implanted together with the adjacent tissues (subcutaneous and femur) will be collected for analysis. For the adjacent tissues, the migration and accumulation of chemical elements corresponding to the radiopacifiers around the implanted material will be analysed. Scanning electron microscopy (SEM) and local mapping of chemical elements (EDS) will be performed. Tissue samples will also be analysed at the material/tissue interface using X-ray fluorescence (m-XRF) and the element quantification will be performed using inductively coupled plasma mass spectrometry (ICP-MS). The implanted cements will be analysed for their degradation using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) to determine the chemical interaction with tissues. Besides, a volume of 1.0 ml of blood will be collected for biochemical evaluations of liver functions and renal functional parameters. After 30 days, half of the animals (n = 50) will be sacrificed and the rest after 180 days (n = 50); and, similarly, the 10 animals in the negative control group. The subcutaneous tissue in contact with the implanted material will be collected and fixed in 10% formalin for histological analysis and determination of inflammation scores. Samples will be collected from liver, brain and kidneys for processing, histological and immunohistochemical analysis. The results will be submitted to the D'Agostino and Pearson tests to verify the normal distribution. For all tests, a significance level of 5% will be considered.