In vitro biocompatibility of a novel Fe2O3 based glass ionomer cement.
BACKGROUND
Since their invention in the late 1960s, glass ionomer cements (GICs) have been used extensively in dentistry but recently they have also been utilised in ear nose and throat (ENT) surgery. Unfortunately, Al3+, a component of conventional ionomer glasses, has been linked to poor bone mineralisation and neurotoxicity.


OBJECTIVE
The aim of the research was to modify a commercial ionomer glass composition by substituting Al2O3 with Fe2O3.


METHODS
Glasses with the following molar compositions were fabricated: 4.5SiO2*3M2O3*XP2O5*3CaO*2CaF2 (M = Al or Fe, X = 0-1.5). The glasses were characterised using X-ray fluorescence (XRF) and X-ray powder diffraction (XRD). Cements were prepared using a standard ratio of; 1 g of glass powder: 0.2 g of dried polyacrylic acid: 0.3 g of 10% tartaric acid solution. Cement formation was assessed using a Gilmore needle and in vitro biocompatibility was investigated for novel cement formulations.


RESULTS
XRF revealed that the Fe2O3-based glasses had Al2O3 contamination from the crucibles and also had undergone substantial F- losses. XRD gave peaks that corresponded to magnetite Fe3O4 (JCPDS # 19-629) in all compositions. Apatite Ca5(PO4)3(OH,F) (JCPDS # 15-876) was identified in P2O5 containing glasses. It was possible to fabricate cements from all of the Fe2O3-based ionomer glasses. Good in vitro biocompatibility was observed for the Fe2O3-based cements.


CONCLUSIONS
Ionomer glasses may be prepared by entirely replacing Al2O3 with Fe2O3. Cement setting times appeared to be related to P2O5 content. Fe2O3-based cements showed good in vitro biocompatibility.
Centre for Biomaterials & Tissue Engineering School of Clinical Dentistry, University of Sheffield Claremont Crescent, Sheffield S10 2TA, UK.
K
K
Hurrell-Gillingham
I M
IM
Reaney
I
I
Brook
P V
PV
Hatton
D000818:Animals; D045744:Cell Line, Tumor; D048430:Cell Shape; D018360:Crystallography, X-Ray; D005290:Ferric Compounds / Q000633:toxicity*; D005898:Glass / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008928:Mitochondria / Q000187:drug effects; D051381:Rats
D005290:Ferric Compounds; D005899:Glass Ionomer Cements; C000499:ferric oxide