AN IN-VITRO STUDY OF THE EFFECT OF RESTORATIVE TECHNIQUE ON MARGINAL LEAKAGE IN POSTERIOR COMPOSITES

The purpose of this in vitro study was to compare marginal leakage of class 2 light-cured composite resin restorations, with different inser tion and polymerization techniques. Fifty sound premolars extracted fo r prosthetic purposes were used in the study. Conservative class 2 (MO D) preparations were made in all teeth, with one proximogingival margi n on enamel and the other on cementum. All the preparations and restor ations were performed by the same operator utilizing the same restorat ive materials. After restoration the teeth were thermocycled and their gingival margins exposed to a dye. Results showed that the kind of ma trix system had no significant influence upon the degree of marginal l eakage on enamel. On cementum, oblique and horizontal incremental inse rtion and polymerization techniques using the collimator cone exhibite d the least leakage, while the clear matrix band/reflective wedge tech nique presented the greatest leakage.