Papers by Author: F.J.C. Braga

Abstract: The bovine bone and sintetic hydroxyapatite (HA) bioceramics are reference materials to employment as a bone substitute, however, their slow rate of degradation and its low rate of bioactivity index (Ib) are presented as limiting factors for application as bone graft. In contrast, the bioglass is a resorbable and osteoinductive material. the present work objective the development of composites of dispersed bovine bone or sintetic HA in silicate-phosphate bioglass, seeking to obtain a biomaterial with properties suitable for application as bone grafts. The composites were prepared by mixing between the powder components followed by sintering for 1h. Were used HA and bioglass (45S5) with particle size <240μm. The tested proportions of HA/45S5 were 20/80, 30/70 and 40/60 (wt%). The composites characterization was made employing scanning electron microscopy, Infra-Red Spectrometry and hydrolytic resistance test. The test results indicate the potential use of the materials developed for applications such as bone graft.

Abstract: Alumina and zirconia-alumina composite has been micro-structured in air using femtosecond laser. The threshold fluence of 6.2 J.cm^-2 found in this work is close to that found published in literature [1]. In the case of Al-Zr, the threshold fluence is 2.2 J.cm^-2.Surface femtosecond laser treatment increase the apatite deposition by biomimetic method on alumina and alumina-zirconia composite and depends on the condition of laser treatments.

Abstract: he scope of this paper is focused on surface modification process by laser beam irradiation in pure metallic titanium inducing by ablation phenomenon such non stable oxides formation on the irradiated surface. The present study correlates the pulsed laser beam parameter conditions used to irradiate pure metallic titanium and its resulting crystalline phases on the surface with the deposited calcium phosphate layer on it.