Ceramics-Silikáty 57 (4) 313-318 (2013)

EFFECT OF SINTERING TEMPERATURE ON MICROSTRUCTURE AND IN-VITRO BEHAVIOR OF BIOACTIVE GLASS-CERAMICS

In this work, powders of the composition (CaO 46- SiO₂ 34- P₂O₅ 14.5- MgO 4- CaF₂ 1- MgF₂ 0.5) (wt. %) were thoroughly mixed and melted in a muffle furnace. The melt was quenched in water to form glass. Three glass-ceramics were prepared by sintering glass samples at three different temperatures 850, 900 and 950°C according to the exothermal peaks of DTA. The DTA peaks correspond to the bioactive crystalline phases hydroxyapatite (HA) and wollastonite as confirmed by the XRD data. Study of diameter-shrinkage co-efficient and bulk-density of samples revealed higher densification rate for the range 900 - 950°C than that for the range 850 - 900°C.SEM and optical microscope results illustrated a tendency towards closely packed structure and increasing grain size with the increase of sintering temperature. The samples were immersed in SBF for 30 days at room temperature for in-vitro evaluation.EDS analysis, showing the presence of carbon (C) along with calcium (Ca) and phosphorus (P) suggests the formation of hydroxycarbonate-apatite (HCA) phase that indicates the bioactivity of the material which increases with the increase of sintering temperature.

Keywords: Oxy-acetylene blue flame, Hydroxyapatite HA, Wollastonite, Diameter shrinkage co-efficient, Density