Chemical Durability of Alumina and Selected Glasses in Simulated Body Fluid

Abstract

Biocompatible ceramics, glasses, and glass-ceramics are gaining increased importance in biotechnological applications. Ceramic materials can be bioinert, bioactive, bioresorbable, and biotoxic1. The chemical durability of bioceramics is of concern for many biotechnological applications such as bone implants, bone defect fillings, and drug delivery. Crystalline ceramics such as A12O3 and partially stabilized ZrO2 (PSZ) and various glasses based on SiO2 have been used for a range of biomedical applications. A12O3 and PSZ are known to be nearly bioinert materials. Examples of their use include dental implants, ball and socket hip replacements, knee prostheses, bone screws, and segmental bone replacements2. These materials can be used in the dense form where bone attachment is of mechanical nature, for example by bone growth into surface irregularities. A second possibility is the use of porous inert implants where bone can grow into porosities and a better mechanical attachment occurs. Bioactive glasses join the bone by chemical attachment, which is usually stronger than mechanical attachment. It is commonly accepted that the prerequisite for glasses and glass-ceramics to chemically attach to bone is the formation of a hydroxycarbonate apatite (HCA) layer3. 45S5 Bioglass® is the first commercialized glass with such features.