The modified super-closed sandwich technique

The restoration of large Class II cavities with photo-activated composite resin is technically demanding and time consuming and often results in early failure due to sensitivity, secondary caries or tooth substrate fracture. This is often a result of the net volumetric shrinkage of the resin on photo-activation setting up stresses at the restoration-tooth substrate interface giving rise to bond degradation or cuspal fracture, or both. The novel use of an auto-cure glass ionomer cement as a mega-filler completely enclosed by composite resin may offer a strategy to reduce these stresses.

The Glass Ionomer Composite Super-Closed Sandwich technique was originally described by Magne.1 This is an elegant solution whereby the dentine is initially hybridized with a 4th Generation Bonding Agent (Optibond FL, Kerr, Peterborough, UK). The proximal walls are established with paste composite and pure glass ionomer is injected as a dentine substitute. The occlusal surface is then closed with composite, creating a sealed unit. In this model, the glass ionomer is not bonded to the composite, but rather acts as a ‘Mega-Filler’ particle, reducing polymerization stresses.