Polymerization shrinkage of flowable composites were analyzed with new generation micro computed tomography device (micro-ct)

ABSTRACT Objectives: The purpose of this study, eigth different flowable composites were analyzed with new generation Micro Computed Tomography Device (Micro - CT Skyscan 1172) for polymerization shrinkage. Materials and methods: Flowable composite resins and bulk fill flowable composite resins were used in this study. 4x6 mm standard Teflon molds were used for bulk fill composites can be applied to the cavity up to 4 mm thick. 2x6 mm standard Teflon molds are used for flowable composite resins. Different flowable dental composite resin was used for each group. Composite material were placed in separate standard patterns for each group and Micro CT- Skyscan 1172 device with camera pixel size 9 µm, voltage 100 kV, 100 milliamps, the rotation angle of reconstructor was 360 degrees, the angle of rotation were set to be 2 degrees can be used and samples were screened for one hour before polimerization with LED ligth cure. The inner chamber of the device during scanning was dark so, shrinkage was not observed in the material. After scanning, the material was polymerized with LED ligth for 40 seconds and screened again with the same parameters of Skyscan 1172 device. Polymerization shrinkage of the scanned samples were calculated with CTAn software program. 10 samples for each group; 5 samples prior to polymerization and 5 samples after polymerization was evaluated. Conclusion: When the percentage differences in the parameters after the polymerization of the materials were examined; polymerization shrinkage was observed mostly in CHF group and least in XTB group. Key Words: Flowable Composites, Micro - CT SkyScan 1172, Polymerization Shrinkage