Avaliação in vitro do compósito Al2O3/CaPs para uso na cirurgia bucomaxilofacial.

Abstract

This paper aims to obtain and characterize alumina/calcium phosphate composite and to evaluate in vitro and in vivo its effect as bone reconstruction material for application in maxillofacial traumatology as a substitute for bone loss. The work was divided into two stages: Stage I - chemical synthesis of calcium phosphate, preparation of alumina/calcium phosphate composites, and characterization, and Stage II - study in vitro and in vivo of composites in rabbit tibiae. The samples and composites were characterized by X ray diffraction, infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, particle size distribution, nitrogen adsorption, geometric density and diametrical compression. Before being implemented, the cytotoxicity was evaluated in vitro. After euthanasia it was performed histological and radiological evaluation of the grafted areas. The results confirm obtaining of calcium phosphate, whose predominant phase was calcium pyrophosphate and secondary phases were tetracalcium phosphate and hydroxyapatite. The obtained composites presented structure constituted of alumina (matrix) as main phase and calcium pyrophosphate as the secondary phase. All composite presented microstructure consisting of well-defined grains of alumina (Al2O3) and calcium phosphate. The increase in calcium phosphate content in the composites caused an increase in grain size and a reduction in compressive strength when compared to the compressive strength of pure alumina. The in vitro study (cytotoxicity) indicated cell growth for all composites evaluated, including the pure alumina. The in vivo study allowed us to evaluate after euthanasia that the composites implanted in the rabbit tibia e were biocompatible, being a promising material for use in maxillofacial traumatology as a substitute for bone loss.