The rapid increases in the development of new restorative materials and techniques researches have become more involved in determining theability of each new material to adapt to the tooth without leakage and its consequent risk to the vitality of the tooth, post operative sensitivity, marginal staining and secondary caries - so that in future, marginal leakage will not be a severe post- restorative complication. An ideal restorative material should satisfy many requirements, including a good seal, a durable bond tooth, sufficient mechanical strength and low viscosity, resistance against disintegration, tissue compatability and ease of handling.