In this paper we summarize past and present research at Abo Akademi University on the measurement and modeling of the physical properties and the bioactive response of bioactive glasses as functions of the oxide composition. The first bioactive glass, 45S5 is still the fastest responding glass when implanted in the human body. However, 45S5 is apt to crystallize when heated, thus limiting the product types that can be made by hot-working. Thus, 45S5 is used mainly as monoliths or powdered glass. A lower bioactivity and a higher chemical durability may be valuable properties in clinical applications based on special product forms such as sintered porous implants or continuous fibers. The focus of the research being reviewed has been on developing tools for finding novel compositions of bioactive glasses with unique combinations of properties. The working properties were expressed with models for viscosity and crystallization characteristics of the glasses. Changes in simulated body fluid and in glasses after immersion were used to characterize and give basis to models of the in vitro bioactivity of the glasses as functions of the oxide composition. These models can be used for finding compositions of bioactive glasses with a desired product form (monoliths, fibers, microspheres or porous implants) and a desired in vitro bioactivity ranging from very bioactive to almost inert compositions.
- bioactive glass
- oxide composition