Microleakage and shear punch bond strength in class II primary molars cavities restored with low shrink silorane based versus methacrylate based composite using three different techniques.

Objectives: This in vitro study aimed to evaluate the gingival microleakage in class II cavities in primary molars restored with a low shrink silorane resin composite (Filtek P90) or a nanohybride composite resin (Filtek supreme XT) using three different techniques, (total bonding, closed or open sandwich techniques) lined by nano-filled resin modified glass ionomer cement RMGIC (Ketac N100). Additionally, the shear punch bond strength between the two types of composite and KNIO0 was also examined.

Study Design: For microleakage test, two standardized class II slot cavities were prepared in proximal surfaces of 60 sound extracted primary molars which were divided into 2 groups of 30 each according to the type of composite.