The marginal seal of various restorative materials in primary molars.

The use of resin composite restorations in posterior teeth has become an accepted clinical procedure. Microleakage at the posterior composite/tooth interface is a major problem. The in vitro quality of the marginal seal was tested in eighty teeth extracted for orthodontic reasons using a glass-ionomer cement reinforced with amalgam, two light self-curing glass-ionomer cements and a compomer. All the teeth were subjected to thermocycling to simulate clinical situation. Compomers showed the best mechanical and esthetic properties combined with a good marginal seal.