The setting chemistry of glass ionomer cement

Abstract

The setting chemistry of glass ionomer cement was investigated by using mechanical determination of compressive strength at predetermined intervals, and measurement of structure changes of corresponding fracture sample by means of IR spectra and differential scanning calorimetry (DSC). Zinc polycarboxylate cement was used as a comparison sample. The compressive strength of glass ionomer cement (GIC) increases with aging. IR spectra and DSC of corresponding fracture sample show the structure changes of the matrix and interface layer comprising of silica gel during the predetermined intervals studied, however, no significant changes occur in the zinc polycarxyolate cement. Hence the structure changes of the matrix and or interface layer are responsible for compressive strength increasing with aging. The structure changes include the crosslink density, the ratio of complex form to ionic form, the content ratio of Al-PAA to Ca-PAA, the forming and maturing process of the interface layer comprising of silica gel.

Keywords

IR / DSC / glass ionomer cement / compressive strength / set reaction

References

[1] Hatton PV, Brook IM. Characterisation of the Ultrastructure of Glass-ionomer Cement. Br. Dent. J., 1992, 173: 275-277.

[2] Wasson EA, Nicholson JW. New Aspects of the Setting of Glass-ionomer Cements. J Dent Res., 1993, 72: 481-483.

[3] Matsuys S. IR and NMR Analyses of the Hardening and Maturation of Glass-ionomer Cement. J. Dent Res., 1996, 75: 1920-7.

[4] Nicholson JW. Chemistry of Glass-ionomer Cements: A Review. Biomaterials, 1998, 19: 485-494.

[5] Nicholson JW. A Study of Cements Formed by Aqueous lactic Acid and Aluminosilicate Glass. J. Mater. Sci. Mater. Med., 2002, 13: 417-419.

[6] De Maeyer EAP, Verbeeck RMH. Stoichometry of the caching Process of Fluoride-containing Aluminosilicate Glass-ionomer Glasses. J. Dent. Res., 1999, 78: 1312-1318.

[7] Williams JA, Billington RW. Increase in Compressive Strength of Glass Ionomer Restorative Materials with Respect to Time Periods of 1 Day to 4 Months. J. Oral Rehabil, 1991, 18: 163-168.

[8] Pearson GJ, Atkinson AS. Long-term Flexural Strength of Glass Ionomer Cements. Biomaterials, 1991, 12: 658-660.

[9] Cattani-Lorente Maria-Angeles, Godin Chantal, Meyer Jean-Mare. Mechanical Behavior of Glass Ionomer Cements Affected by Long-term Storage in Water. Dent. Mater., 1994, 10: 37-44.

[10] Wilson AD. The Chemistry of Dental Cements. Chem. Soc. Rev., 1978, 7: 265-296.

[11] ISO 9917 (1991). International Standard. Dental Waterbased Cements

[12] Soda R. Infrared Absorption Spectra of Quatz and Some Other Silica Modification. Bull. Chem. Soc. Jpn., 1961, 34: 1491-1495.

[13] Mozgawa W, Sitarz M, Rokita M. Spectroscopic Studied of Different Aluminosilicate Structures. J. Mol. Structure, 1999, 511–512: 251-257.

[14] De Maeyer EAP, Verbeeck RMH. Infrared Spectrometric Study of Acid-degradable Glasses. J. Dent Res., 2002, 81: 552-555.

[15] Crisp S, Pringuer MA. Reaction in Glass Ionomer Cements: II: An Infrared Spectroscopic Study. J. Dent Res., 1974, 53: 1414-1419.

[16] Prosser Crisp S. An Infrared Spectroscopic Study of Cement Formation between Metal Oxides and Aqueous Solutions of Polyacrylic Acid. J. Mater. Sci., 1976, 11: 36-48.