Bioactive glass (S53P4) consists only of elements naturally existing in the body (Si, Na, Ca, and P). It is characterised by its ability to attach firmly to living tissue, facilitate tissue growth, bond chemically with surrounding bone in an implantation bed and promote new bone formation in the implanted area. In contact with body fluids bioactive glass works by leaching out ions leading to the transformation of the glass surface chemically into one that by its chemical composition and structure resembles the mineral phase found in natural bone. This phenomenon has been shown to effectively inhibit bacterial growth. In contact with an aqueous solution the bioactive glass develops a silica-gel layer on the glass surface which acts as a template for calcium phosphate (CaP) precipitation. The CaP crystallizes to a hydroxyapatite surface and enables bonding of the bioactive glass to the surrounding bone. This makes bioactive glass a unique material for filling defects and replacing damaged bony tissue.
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