This study explores the interaction between bioactive glasses and dentin from extracted human teeth in simulated oral conditions. Bioactive glasses in the Na2O-CaO-P2O5-SiO2 and MgO-CaO-P2O5-SiO2 systems were prepared as polished disks. Teeth were prepared by grinding to expose dentin and etching with phosphoric acid. A layer of saliva was placed between the two, and the pair was secured with an elastic band and immersed in saliva at 37°C for 5, 21 or 42 days. The bioactive glasses adhered to dentin, while controls showed no such interaction. A continuous interface between the bioactive glass and dentin was imaged using cryogenic-scanning electron microscopy (SEM). However, after alcohol dehydration and critical point drying, fracture occurred due to stresses from dentin shrinkage. SEM investigations showed a microstructurally different material at the fractured interface. Chemical analyses revealed that ions from the glass penetrated into the dentin and that the surface of the glass in contact with the dentin was modified. Microdiffractometry showed the presence of apatite at the interface. Bonding appears to be due to an affinity of collagen for the glass surface and chemical interaction between the dentin and glass, leading to apatite formation at the interface.
|Number of pages
|Journal of Materials Science: Materials in Medicine
|Published - 2002
Bibliographical noteFunding Information:
The authors thank Dr Hsuan Huang for helpful discussions, Linda Sauer for assistance with microdif-fractometry, and Dr Ashok Menon for sharing his cryo-SEM expertise. This work was supported by the National Science Foundation (DMR-9357502) and in part by the MRSEC Program of the National Science Foundation under Award Number DMR-9809364. Dr Pascal Magne is funded by the Swiss National Science Foundation (81 GE-50071) and the Swiss Foundation for Medical, Biological Grant s.