Bonding strength of the apatite layer formed on glass-ceramic apatite-wollastonite-polyethylene composites

Bioactive glass‐ceramic apatite‐wollastonite (A‐W) has been incorporated into polyethylene in particulate form to create new bioactive composites for potential maxillofacial applications. The effects of varying the volume fraction of glass‐ceramic A‐W filler and the glass‐ceramic A‐W particle size were investigated by measuring the bonding strength of the bonelike apatite layer formed on the surface of glass‐ceramic A‐W–polyethylene composites. The bonding strength was evaluated via a modified ASTM C‐333 standard in which a tensile stress was applied to the substrate and the strength of the bioactive layer was compared with that formed on commercially available hydroxyapatite–polyethylene composite samples, HAPEX™. The composites demonstrated greater bonding strength with increased filler content and reduced filler particle size (maximum 6.9 ± 0.5 MPa) and a marginally greater bonding strength as compared with HAPEX™ (2.8 ± 0.5 MPa), when glass‐ceramic A‐W–polyethylene composite samples with the same filler content were tested. The higher bonding strength of the apatite layer formed on the A‐W–polyethylene composite samples suggests that, in addition to maxillofacial applications, these composites might also be utilized in applications involving higher levels of load bearing. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 952–959, 2003