Placement procedures for composite-based resin restorations are very technique-sensitive.The operating field must be kept absolutely clean and dry during the insertion of the composite-based resins. Inability to achieve moisture control will lead to clinical problems; therefore, placement of a rubber dam is highly recommended, if not essential. Water, moisture or saliva are contaminants.
Good marginal adaptation requires adequate physical and mechanical properties of the filling material and its careful manipulation. The use of composite resin for direct restorations demands careful and thoughtful clinical application. Incremental layering techniques have been recognized as the technique of choice to minimize stresses from polymerization shrinkage. Gaps may develop when the bonding capacity of the adhesive system is insufficient to resist the forces of polymerization shrinkage of the composite.
Although the universal matrix band is a versatile instrument, it does not meet all criteria with respect to contour and form. Two major disadvantages of the universal matrix are that it allows curing only from the occlusal aspect and is not anatomically shaped for contour. Precontour bands requiring little or no adjustment are desirable. The matrix will provide axial confinement of the resin and convexity to the proximal surface being restored. Prewedging of the tooth will protect the interseptal dam and soft tissue, prevent damage during tooth preparation and create a rapid tooth separation to compensate for the matrix band. It is therefore easier to achieve adequate contact with the adjacent tooth following removal of the matrix once the resin is inserted.
Using finite element analysis on Class V restorations, it was suggested that bulk filling of light-cured composite-based resins should be used in restorations that are sufficiently shallow to be cured to their full depth. A previous study reported similar results concluding that none of the placement techniques (incremental or bulk) improved the adaptation at the gingival margin. They did demonstrate, however, that the incremental techniques ensured the complete polymerization of the composite-based resin
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