Bioactive composites: effect of different calcium phosphate compounds and organic matrix composition on the remineralizing potential and physicochemical properties of experimental materials

Abstract

The development of bioactive composites is a challenge for researchers searching for formulations with remineralizing action without compromising the physical and chemical properties of the restorative material. Objectives: the aim of this study is to evaluate the bioactivity potential, degree of conversion, volumetric shrinkage and mechanical properties of experimental composites containing calcium phosphate compounds. The experiment will test composites presenting different amounts of inorganic filler and the effect of the addition of HEMA to the organic matrix. Materials and methods: in the first part of the project, amorphous calcium phosphate (ACP), dicalcium phosphate anhydrous (DCPA) or tricalcium phosphate (TCP) particles will be incorporated in an organic matrix containing BisGMA and TEGDMA to evaluate the buffering capacity and release of calcium and phosphate ions by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The second stage will determine the effects of adding 40% (by weight) of calcium phosphate in composites containing different amounts of barium glass on the degree of conversion (FTIR spectroscopy), volumetric shrinkage (Helium pycnometer), fracture toughness (method "single-edge notched beam"), biaxial flexure strength and elastic modulus. The bioactivity of these materials will also be evaluated. Effects of HEMA addition to the organic matrix will be evaluated according to the same variables. Data will be submitted to analysis of variance (ANOVA) and a Tukey's post-hoc test (p<0.05%). (AU)