Remineralization effects of glass-ionomer cement

Caries Research Remineralization effects of glass-ionomer cement Background.—The minimal intervention atraumatic restorative treatment approach is a widely used dental treatment for managing dental caries. Its success is closely tied to the ability of glass-ionomer cement (GIC) restorative materials to resist functional stresses, seal the cavities and adjacent enamel fissures, and facilitate dentinal remineralization. Removal of carious dentin must be as complete as possible before a restoration can be placed, but residual dentin is common. The effect of GIC restorative materials on the residual carious dentin in primary molars that had been exfoliated was evaluated to determine if mineral and morphologic changes occur in the residual dentin adjacent to the restorations. Methods.—Four exfoliated teeth that had intact restorations were sectioned and evaluated with use of electron probe microanalysis and scanning electron microscopy. The GICs used included encapsulated Fuji IX GP and Ketac-Molar Aplicap. Each material was placed in cavities prepared with use of the atraumatic restorative treatment approach. Results.—All specimens exhibited degrees of incomplete removal of carious dentin and GIC adherent to the tissues. GIC particles contained carbon, oxygen, fluorine, sodium, and silicon. The Ketac-Molar Aplicap also contained phosphorus, calcium, and lanthanum, and the Fuji IX GP also contained strontium. The 4 specimens showed no statistically significant differences in the degree to which fluorine or strontium penetrated into the residual carious dentin from the GIC material. Distance from the GIC/dentin interface determined the concentrations of

these 2 elements, as well as those of calcium and phosphorus. The degree of dentin tubule destruction and intratubular dentin present immediately below the GIC/dentin interface varied from minimal changes to vertical clefts with complete structural disorganization. Some sites had well-mineralized intratubular dentin at the GIC/dentin interface. It was surmised that the longer the GIC is in intimate contact with dentin, the more mineralized the dentin will be. Discussion.—GIC may play a significant role in the remineralization of subjacent residual carious dentin in primary molars. The study did not address how much GIC contributes to the normal physiologic remineralization that occurs.

Clinical Significance.—Caries may be incompletely removed during cavity preparation. In this in vivo study, teeth exfoliated after restoration with glass ionomer cement demonstrated remineralization of the lesions. The extent of this process remains undetermined.

Smales RJ, Ngo HC, Yip KH-K, et al: Clinical effects of glass ionomer restorations on residual carious dentin in primary molars. Am J Dent 18:188-193, 2005 Reprints available from RJ Smales, 19A Wattle St, Fullarton, Adelaide, South Australia 5063; e-mail: [email protected]

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