Acrylic Bone Cement Modified whit Hydroxiapatyte/Vinyl Acetate. Mechanical, Thermoanalytical Characterization and In Vitro Bioactivity

Bone cements have become biomaterials of great utility in the prosthesis fixation and as substitutes to the bone. The objective of this study is to evaluate the thermo analytical properties such as setting time and peak temperature of polymerization of acrylic bone cement modified with hydroxyapatite/vinyl acetate, to determine the compression strengths and perform in vitro bioactivity tests. Amounts of vinyl acetate component were incorporated in different percentages in acrylic bone cements, all loaded with 30 % of hydroxyapatite CORALINA (R) HAP-200. Curing parameters and mechanical properties were determined finding formulations that comply with the ISO 5833 norm. In vitro bioactivity tests were performed in two cement formulations. The setting time obtained ranged between 3 and 6 minutes and the peak temperature varied between 66 and 88 degrees C. Compression strengths were higher than established in the ISO 5833 regulation for mechanical properties evaluation of acrylic bone cements. The bioactivity was demonstrated by immersion of the samples in simulated body fluid, in which nucleation and crystal growth were observed on the sample surface with similar morphology and composition to biological apatite.