Contribution of the particle-matrix bonding to the mechanical characteristics of composites containing calcium orthophosphate

• Grant number: 23/12176-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Roberto Ruggiero Braga
• Grantee: Letícia Silvestre Lima
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/04737-4 - Dentin remineralization with the use of composite containing calcium orthophosphate particles associated with a Polymer-Induced Liquid Precursor (PILP): material development, in vitro and randomized clinical studies, AP.TEM

Abstract

Several studies have verified that the replacement of silanized glass particles by particles capable of releasing calcium ions (for example, calcium orthophosphates) promotes severe reductions in the fracture strength of resin composites. This weakening is attributed to the lack of chemical union between the resin matrix and the functional particles and to the lower intrinsic resistance of these particles; however, the relative contribution of these two factors is not known. Thus, the aim of this project is to estimate the contribution of the absence of a load-matrix bonding to fracture strength, flexural modulus and microhardness by comparing two series of materials containing increasing fractions of (1) non-silanized barium glass particles and (2) dicalcium phosphate dihydrate particles (DCPD, CaHPO4.2H2O).