Compositional dependence of bioactivity of glasses in the system Na2O-K2O-MgO-CaO-B2O3-P2O5-SiO2

✍ Scribed by Brink, Maria ;Turunen, Tia ;Happonen, Risto-Pekka ;Yli-Urpo, Antti

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 400 KB
• Volume: 37
• Category: Article
• ISSN: 0021-9304
• DOI: 10.1002/(sici)1097-4636(199710)37:1<114::aid-jbm14>3.0.co;2-g

✦ Synopsis

The bioactivity, i.e., bone-bonding ability, of 26 glasses in the system Na 2 O-K 2 O-MgO-CaO-B 2 O 3 -P 2 O 5 -SiO 2 was studied in vivo. This investigation of bioactivity was performed to establish the compositional dependence of bioactivity, and enabled a model to be developed that describes the relation between reactions in vivo and glass composition. Reactions in vivo were investigated by inserting glass implants into rabbit tibia for 8 weeks. The glasses and the surrounding tissue were examined using scanning electron microscopy (SEM), light microscopy, and energy-dispersive X-ray analysis (EDXA). For most of the glasses containing < 59 mol % SiO 2 , SEM and EDXA showed two distinct layers at the glass surface after implantation, one silica-rich and another containing calcium phosphate. The build-up of these layers in vivo was taken as a sign of bioactivity. The in vivo experiments showed that glasses in the investigated system are bioactive when they contain 14-30 mol % alkali oxides, 14-30 mol % alkaline earth oxides, and < 59 mol % SiO 2 . Glasses containing potassium and magnesium bonded to bone in a similar way as bioactive glasses developed so far.