Avaliação do desempenho mecânico de compósitos experimentais contendo partículas de fosfato de cálcio funcionalizadas através de rotas de sínteses alternativas

Abstract

The aim of this study was to evaluate the mechanical properties of resin composites containing different di-calcium phosphate dihydrate (DCPD) particles functionalized with triethylene glycol dimethacrylate (TEGDMA), synthesized by alternative routes and characterized in a previous study. Six groups of nanoparticles were synthesized varying the receptor solution: ammonium phosphate (groups A, B, and C) and calcium nitrate (groups D, E, and F), the time of TEGDMA incorporation (during: groups A and D or after precipitation: groups B and D). Groups C and F correspond to non-functionalized particles. For this study, a BisGMA and TEGDMA resin matrix (1: 1 mol) was manipulated and 20% (in volume) of the six different DCPD particles were added. As a control, two resin materials were manipulated: one experimental material without the incorporation of inorganic particles (RM) and another containing silanized barium glass particles (BG). The materials were evaluated for biaxial flexural strength (BFS) and modulus of elasticity (E) in a universal test machine with a loading rate of 0.5 mm/min. The BFS values ranged from 166 to 83 MPa, being the highest values observed for the RM and BG groups (166 and 142 MPa, respectively) that did not present statistical differences between them. Among the experimental groups containing the DCPD particles, only group D (126 MPa) presented statistically similar values to the BG control. The other groups with DCPD had similar values, ranging from 88 to 83 MPa. The E values ranged from 12 to 4 GPa. The groups of materials containing non-functionalized particles (groups C and F) presented statistically similar values, with values of 10 and 11.8 GPa, respectively. In general, the other groups showed similar behavior among themselves. Among the factors of the different particle synthesis groups, group D showed significant improvements in the mechanical performance of resinous materials.