Studies on preparation and characterization of SiO2-CaO-P2O5 and SiO2-CaO-P2O5-Na2O bioglasses subtituted with ZnO

Bioglasses are important bioactive materials as they are used for the repair and reconstruction of bone tissues,by exhibiting direct bonding with them. we used a sol-gel method to produce the bioglass powders in the systems sio2-cao-na2o-p2o5,sio2-cao-p2o5-zno and sio2-cao-na2o-p2o5-zno. these glasses featured sio2 contents in the range 40-65 mol %,22-24 mol% of cao,2-6 mol % of p2o5,20.5-24 mol % of na2o and 4.5-15.5 mol% of zno. the formed crystalline phases were identified using x-ray diffraction. infrared spectra of the bioglasses were measured before and after immersion in simulated body fluid and the results were compared with the same behavior for the parent bioglasses. experimental results indicate the formation of two main crystalline phases of sodium calcium silicate (na2casi3o8,na2casi3o9) according to the change in the bioglass composition. the effect of introduction of zno in sio2-cao-na2o-p2o5 system leads to the formation of a new crystalline phase of hexasodium tricalcium cyclohexasilicate (na6ca3si6o18). the in vitro studies showed the formation of an apatite-like layer covering areas of the material surface. the influence of both chemical and morphological factors on the in vitro bioactivity has been studied. the apparent density and contact angle variation with time were measured.