The Open Sandwich Technique with Glass Ionomer Cement – a Critical Evaluation

One of the critical goals of adhesive dentistry is to restore the peripheral seal of dentine that is interrupted when enamel is lost as a result of developmental sequelae, trauma, caries or operative intervention such as preparatory excision. For coronal lesions the exposed strata may be bounded by dentine, enamel or both. Manufacturers continue to work vigorously on resin formulations that will restore this peripheral seal with operative ease and absolute durability. Difficulties with Class II restorations led to the development of open-sandwich restorations: a glass ionomer cement (GIC) or a resin-modified glass ionomer cement (RMGIC) placed between the dentin gingival margins and occlusal composite restorations. GIC presents two interesting features in restorations by bonding spontaneously to dentin and releasing fluoride. These sandwich restorations are less sensitive to technique than composite restorations and show a high percentage of gap-free interfacial adaptation to dentin.