Objectives: To assess the influence of preheating and sonic oscillation of bulk-fill composite on marginal adaptation of class II restorations.
Materials and methods: 30 extracted molars were collected, and standardized compound class II cavities were prepared. Teeth were classified into three groups (n=10) according to placement techniques. Group I, the composite material was placed in bulk to fill the prepared cavity using a plastic filling instrument. Group II, composite syringes were placed in the Therma-Flo device before placement into the cavities. Group III, the composite material was placed in bulk to fill the prepared cavity using a plastic filling instrument then adapted by compothixo oscillating packing instrument. After finishing and polishing, the specimens were subjected to thermocycling. Marginal analysis was carried out using Scanning Electron Microscope at 500 x magnifications. The overall margins were investigated, and the maximum gaps were measured.
Results: Although preheated composite produce better marginal adaptation, there was no significant difference between all tested groups.
CONCLUSION
None of the placement techniques produced gap-free margins. Preheated composite improved marginal adaptation