Effect of Extended Polymerızation Tımes on the Degree of Conversion and Microhardness of Resin Composites

Objective: The aim of this study was to evaluate the polymerization properties of bulk-fill and conventional resin composites in terms of the degree of conversion (DC) and microhardness (MH) at different polymerization times. Materials and Methods: In this study three different polymerization times (20 s, 60 s, and 100 s) were applied to disc shaped samples (6 mm wide; and 2 mm high) prepared from two bulk-fill resin composites (Filtek One Bulk Fill Restorative, X-tra Fil) and two traditional resin composites (Filtek Z550, Charisma Smart). The DC of the polymerized samples was measured with a FT-IR/ATR device, and the MH values were measured with a Vickers hardness device. The collected data were subjected to statistical analysis. Results: The results of the FT-IR analysis and Vickers microhardness test demonstrated that the DC and MH values of the groups exposed to 100 s of light curing were significantly higher than those of the other groups (p