Abstract
Glass ionomer cement developed by Wilson et al.1971 is a very similar material to silicate cement. It consists of ion leachable alminosilicate glass and fluoride is contained as flux.
The present study was carried out to examine the inhibitory effect of glass ionomer cement on recurrent caries. Prior to the experiment, microleakage of the cement, the amount of fluoride released from setting cement, and alteration of pH of the cement were measured, and then the influence of the cement on the enamel cavity wall was compared to that of silicate cement and composite resin in vitro. The influence of the dentinal cavity wall was also examined in vivo.
The results obtained from the present studies were as follows. In the enamel cavity wall, the improvement of acid resistance and crystallinity in the a-axis of the enamel apatite were noticed, and this was considered to be improved due to fluoride uptake into the tooth structure from the glass ionomer cement. However, in the inner enamel cavity wall, slight subsurface demineralization was noticed, and a slight decrease of crystallinity in the c-axis of the enamel apatite was noticed. This may be considered to caused by the residual acid of this cement.
In the dentinal cavity wall, fluoride uptake up to approximately 100μm depth was detected, and hypermineralized peritubular dentin with a gradually increased width in the surface layer of dentinal cavity wall was observed.
Based on those results, it was suggested that glass ionomer cement has an inhibitory effect on caries recurring at the cavity margin.
