Estudo comparativo experimental de compósito bioativo de matriz polimérica para aplicação em cirurgia plástica ocular na substituição tecidual

Abstract

Purpose: To compare two new biomaterials: Composite 10% (Engineering School - Universidade Federal de Minas Gerais - UFMG - Brazil) and Composite 20% (Engineering School - Universidade Federal de Minas Gerais - UFMG - Brazil), with two similar materials as control: Medpor™ (Porex Surgical Inc. - USA) e Polipore™ (Homus Com. Ind. Ltda - BRASIL). Methods: In vivo randomized experimental double blind study: a transconjunctival approach was performed in both cartilaginous superior orbital walls of 28 rabbits for 56 implants divided into 4 groups: GI: Composite 10%/Medpor™; GII: Composite 10%/ Polipore™; GIII: Composite 20%/Medpor™; GIV: Composite 20%/Polipore™. The mean rate for implant time of permanence was 19.7 weeks. The Student's t test was used for statistical analysis. Results: Revealed similar biocompatibility of all materials and none of the implants was extruded; one Composite 20% had partial exposure. Histomorphometry showed a greater bioactivity of the composites with significantly thicker fibrous encapsulation, with more collagen and fibroblasts, exuberant angiogenesis, and a lower inflammatory cell mean compared to controls. The presence of precipitation of a hydroxycarbonate apatite layer, which acts as an implant-tissue bond was confirmed. Composites presented a smaller tissular invasion index of the pores compared to controls. Conclusions: The composites showed a good biocompatibility and some additional advantage over the Medpor™ and Polipore™ controls.