Cimento ósseo de brushita obtido pelo método de dissolução-precipitação.

Abstract

Bone diseases have been one of the major challenges of regenerative medicine since the 20th century. Among the recent and important causes are population longevity and the number of traumas by accident. Regenerative medicine is the part of biomaterials science and engineering that addresses the replacement or regeneration of bone tissue. One of the most important materials are bone cement, since its function of joining and providing a phase transition to have physical and biological results suitable for different applications such as dentistry and orthopedics. Brushite cements may be synthesized from the reaction of wollastonite with an acid having osteoconductive and biocompatible properties, supporting the osteoblastic cells for both proliferation and cell differentiation, in addition to which solubility is better at physiological pH than Apatites and β-TCP. These biomaterials were also investigated in the bone repair process inducing the regeneration and osteoinduction of the involved cells. Thus, the objective of this study was to develop a bone cement with different concentrations of brushite phase from the synthesis of wollastonite and orthophosphoric acid by the dissolution-precipitation method and to evaluate its microstructural and physicochemical properties. Bone cement test specimens with different brushite phase concentrations (30, 50 and 70%) were prepared from 5 g of wollastonite by mixing until homogenized with an aqueous solution of phosphoric acid, the obtained paste was placed in a mold Teflon a Curing for 24 hours at a temperature of 25 ± 5 °C and relative humidity of about 80 ± 10%. The specimens of the cements were characterized by Xray diffraction, Raman spectroscopy, scanning electron microscopy, mechanical compression test and manipulation properties. The best results were found for the prepared cement using a 70% concentration, with mixing, handling and curing times of 1 and 6 min and 7 min, respectively. The maximum temperature of the cement mass during the reaction was 97 ° C, compatible with clinical use, with compressive strength of 12, 13 and 19 MPa at 1, 3 and 7 days after curing, respectively, similar to bone strength Spongy or trabecular.