Glass-ionomer Cements of Improved Flexural Strength

The effect of glass and polyacid composition on cement strength has been investigated with a view to improving the glass-ionomer cements. The flexural strength of glass-ionomer cements was found to be greatly dependent on the glass and polyelectrolyte used to prepare them. Opaque and opal glasses containing crystallites tended to yield cements with high flexural strength. Flexural strength was also found to be increased by increasing the molecular weight of the polyacid. In water-setting systems, cement strength was shown to be critically dependent on the glasslpolyacid ratio. </jats:p

Materials Science

A study has been made on improving the adhesion of a glass-ionomer cement by the chemical treatment of dentin and enamel surfaces. The most effective surface conditioners were high molecular weight substances containing a multiplicity of functional groups capable of hydrogen bonding. Low molecular weight chelating agents which dissolve calciferous material and dramatically alter the surfaces of enamel and dentin are less effective. </jats:p