Evaluation of the slumping property of dental composites during modeling

Background/purpose: The aim of this study was to investigate the slumping resistance during modeling of four light-initiated composite materials before their polymerization. Materials and methods: Filtek Supreme XT (3M-ESPE, Seefeld, Germany), Enamel Plus HFO (GDF, Germany), Tetric EvoCeram (Vivadent, Liechtenstein), and Synergy D6 (Coltene, Whaledent AG, Switzerland) were used to measure the shape deformation (i.e., slumping). Three different molar shapes of composites were obtained from customized silicon molds. The surface of each sample was digitized with a 3D laser scanner (400 slices, with a lateral resolution of 25 gm) every minute up to the first 4 minutes. The 3D datasets at each point in time were numerically superimposed with matching software. Differences in deformation were calculated relative to the baseline measurement. Results: We found the lowest surface change for Synergy D6 with tooth molds 1 and 2 (21-37 mu m) and Tetric EvoCeram with tooth mold 3 (29-37 mu m). Enamel Plus HFO had the largest surface change of all tooth molds and all observed time intervals. Significant differences (P < 0.05) in material type factors were determined among all tested composites. Synergy D6 and Tetric EvoCeram presented no significant differences with tooth mold 1. Conclusion: With this method, the handling characteristic of different composite materials can be identified. Results of this study can quantify slumping differences and help select materials for their intended use. Copyright (C) 2012, Association for Dental Sciences of the Republic of China. Published by Elsevier Taiwan LLC. All rights reserved