Turkaslan S.S.Deger Y.2024-04-242024-04-2420161309-100Xhttps://hdl.handle.net/11468/25004The mechanical properties and clinical performance of cements are affected by their degree of conversion; inadequate polymerization may lead to failures. This study evaluated the polymerization proportion of a dual-cure luting cement beneath two different fiber-reinforced composite restorations of various thicknesses utilizing a degree of conversion (DC) technique. Two types of glass fiber (GF); Everstick (Stick Tec, Turku, Finland) and Vectris Frame (Ivoclar, Vivadent Schaan, Liechtenstein) were used to prepare laminate veneer simulations. The polymerization course of the composite resin luting cement (Rely X ARC/3M-ESPE) was investigated using Fourier-transformed infrared spectroscopy (FT-IR) to evaluate the quantity of remaining carbon-carbon double bonds in the specimen beneath two types of fiber-reinforced composite restorations of three thicknesses. The polymerization proportion of Rely X ARC cement beneath Everstick-reinforced composite restorations was similar to the composite-only group (p>0.005) at 0.5-, 1-, and 1.5-mm thicknesses after the light-curing period (40 sec) utilizing the DC technique. The polymerization proportion was decreased when the thickness (1 and 1.5 mm) of Vectris Frame was increased (p<0.005). The polymerization process was continued using the auto-polymerization mechanism after 1020 sec, but the 1.5-mm Vectris Frame-reinforced composite group exhibited the lowest polymerization proportion of all groups (p<0.005). In conclusion, an increased thickness of fiber-reinforced composite resin may negatively affect the polymerization proportion of the underlying resin cement, depending on the fiber material used.eninfo:eu-repo/semantics/closedAccessDegree Of ConversionFiber-Reinforced Composite ResinsLuting CementPolymerizationArticle9118222-s2.0-84978680221Q3