In vitro microleakage of Class V composite resin restorations with and without light-cured glass-ionomer (poly alkenoate) cement lining.

The restoration of Class V cavities with composite resin when the cervical cavity margin extends onto the root surface poses a special problem with regard to marginal seal. The use of glass-ionomer (poly alkenoate) cement (GIC) linings has not overcome this problem completely. The efficacy of a new light-cured GIC lining was tested in vitro, as was the use of a modern dentine-bonding agent. The light-cured GIC lining afforded a reliable marginal seal but the efficacy of the dentine-bonding agent related to the time of finishing of the composite restoration.