Microleakage of glass ionomer/composite resin restorations: A laboratory study. 1. The influence of glass ionomer cement

Abstract

Acid-etching of enamel margins, often combined with bevelling and use of a low viscosity resin, has resulted in improved sealing of composite restorations. When enamel is absent and margins involve dentine or cementum, microleakage is more often observed. The use of glass ionomer cement, as both a restorative material and as a base combined with a veneer of composite resin, has been advocated as a means of minimizing microleakage where margins are placed in dentine or cementum. Four restorative techniques incorporating glass ionomer cement were used, in vitro, to restore cervical cavities. After thermal cycling, dye penetration was scored along occlusal and gingival margins. In all instances the gingival margin exhibited a less reliable seal than the occlusal margin. The sandwich restorations produced a superior seal at both occlusal and gingival margins when compared with glass ionomer restorative cement.

A Review of Chemical-approach and Ultramorphological Studies on the Development of Fluoride-releasing Dental Adhesives Comprising New Pre-Reacted Glass Ionomer (PRG) Fillers

“…Several elements penetrated the dentin substrate from the adhesive through the resin-dentin bonded interface. Dynamic SIMS measurement of 19 F, 12 C, 31 P, 16 O, and 18 O in the adhesives of WF and NF revealed that the intensities of O, C, P, and O in WF showed a tendency similar to that of NF. As for the distribution of F-intensity, it increased significantly in WF (Fig.…”

“…However, increasing the PRG-Ca concentration resulted in a decrease in the polymerization reactivity (cal/g) (r=-0.99; p<0.001). Fluoride-releasing dentin adhesives, and in particular glass ionomer-based dentin adhesives, are gaining popularity despite the lack of consensus in the correlation between fluoride release in GICs and their caries-inhibition effect [6][7][8][9][10][11][12] .…”

“…In this manner, fluoride will help to prevent the formation of dental caries [6][7][8] . A number of in vitro studies [9][10][11][12] have demonstrated a decrease in the incidence and severity of recurrent caries around restorations made with materials which release fluoride. Furthermore, recent studies [13][14][15] showed that fluoride-releasing adhesives were effective in inhibiting wall lesions and enhancing the remineralization of decalcified dentin.…”

“…Fluoride is taken up by adjacent tooth substrate, and therefore strengthens dentin 5) . This function will prevent the formation of dental caries [6][7][8][9][10][11][12] and assist in the remineralization of decalcified enamel and dentin [13][14][15][16] . To prevent the recurrence of secondary caries, the aim of our development strategy was focused an advanced adhesive designed by amalgamating the merits of a self-etching adhesive with fluoride-releasing function.…”

“…However, increasing the PRG-Ca concentration resulted in a decrease in the polymerization reactivity (cal/g) (r=-0.99; p<0.001). Fluoride-releasing dentin adhesives, and in particular glass ionomer-based dentin adhesives, are gaining popularity despite the lack of consensus in the correlation between fluoride release in GICs and their caries-inhibition effect [6][7][8][9][10][11][12] .Unlike the polyalkenoate matrices of GICs that are readily permeable to ion diffusion, conventional ion-leachable glass particles that are used as fillers in most dentin adhesives and restoratives are trapped within copolymerized, highly cross-linked resin matrices. The potential for fluoride release thus relies on the intrinsic acidity of the monomer components to react with these glass fillers, as well as the hydrophilic nature of the polymerized resin matrix to absorb water for the necessary ion movement 25) .…”