engleski

Dimensional Changes of Methacrylate/Silorane-based Composites Measured by Laser Interferometry

Objectives: Polymerization shrinkage and its accompanying polymerization stress maintain continuous interest in resin composite science mainly due to emerging new dental materials. The purpose of this study was to evaluate dimensional changes of 13 methacrylate/silorane–based composite materials. Methods: Linear polymerization shrinkage of 12 different methacrylate-based composites (Tetric EvoCeram (TEC), Filtek Ultimate Body (FUB), Filtek Ultimate Enamel (FUE), Filtek Supreme Body (FSB), Filtek Supreme Enamel (FSE), Gradia Direct Anterior (GDA), Gradia Direct Posterior (GDP), Gaenial (Gae), Empress Direct (ED), GC Kalore (GCK), Charisma Opal (ChO), Charisma Diamond (ChD)) and one silorane-based composite Filtek Siloran (FS) was analysed after 30 seconds photolpolymerization with high, soft-start and low polymerization mode of Bluephase G2 (Ivoclar Vivadent, Liechtenstein) by using laser interferometry. For each material and curing mode 10 composite disc specimens were prepared. Linear dimensional changes were recorded during each second of the polymerization process as well as 30 seconds after illumination. For the statistical analysis ANOVA and Tukey’s post hoc test were used. Results: All the materials exhibited initial expansion followed by shrinkage. The lowest initial expansion showed FUE (0.01±0.01% for low mode polymerization) while lowest shrinkage showed GCK (0.43±0.09% for high mode polymerization). FS showed significantly higher linear shrinkage values for high polymerization mode than all other tested materials (1.58±0.68%). Conclusions: Unlike previous studies where silorane-based system used in FS produced lower shrinkage, our study revealed surprising results because it exhibited higher dimensional changes than other composites. However, all the materials showed very low linear polymerization shrinkage results. Further experiments determining the degree of conversion, microhardness and polymerization stress are necessary for better understanding of polymerization shrinkage behaviour. This study was supported by Ministry of Science, Education and Sports of the Republic of Croatia (Grants: 065-0352851-0410 and 035-0352851-2854).

Composites; Dental materials; Polymerization; Polymerization shrinkage

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