Abstract

BARRIOS DE ARENAS, I; SCHATTNER, C  and  VASQUEZ, M. BIOACTIVIDAD DE VIDRIOS MODIFICADOS DEL SISTEMA Na₂O·CaO·SiO₂·P₂O₅ . Rev. LatinAm. Met. Mat. [online]. 2001, vol.21, n.2, pp.90-95. ISSN 0255-6952.

Special materials have been developed with properties which allow them to be used where a bone replacement is needed. An important property of these materials is the biocompatibility, this property allows that these materials are accepted by the organism although there is not interaction with it. Research works have been carried out on the bioactivity of ceramics and glasses studying their bond to soft or hard tissues. Hench and co-workers discovered that chemical bonding between a bone and certain glass compositions is possible, so called bioactive glasses, encountering them numerous applications in the repair and reconstruction of diseased and damaged tissue, especially hard one (bone). B₂O₃ and Al₂O₃ have been used in bioactive glasses to modify its surface dissolution and durability, melting and forming characteristics; however, Al₂O₃ in contrast to B₂O₃ can inhibit bone bonding, being the acceptable amount of alumina a function of glass composition. The purpose of this work was to study the influence of variable B₂O₃ / Al₂O₃ addition on the bioactivity Na₂O·CaO·SiO₂·P₂O₅ glasses, being the formation of the apatite layer on the glasses surface investigated in vitro soaked at different time intervals, using simulated body fluid, an acellular aqueous solution which has similar ion concentration to human blood plasma. The reaction surface was studied using Scanning Electron Microscopy (SEM) and the deposited layer was analysed by EDX line scans using UTW detector. The compositional profiles of the deposited surface and substrate showed a layer rich in calcium and phosphorous characterised in previous works as apatite. This phase has grown in all studied compositions except those with B₂O₃ / Al₂O₃ contents higher than 0,55.

Keywords : Bioactivity; Biocompatibility; Simulated Body Fluid (SBF); Electron Microscopy.