Effect of light curing on elution of leachable components

Objectives:The purpose of this study is to investigate the influence of curing lights on the elution of leachable components from dental composites. Methods: Two different type light curing units, LED (Elipar Freelight I at 400 mW/cm2) and Halogen (Visilux II at 500 mW/cm2) (3M Dental Products, St Paul, MN, USA) were used for curing. Three different sizes of sample discs (2,4,6 mm) prepared for each material group (Filtek Flow, Filtek A110, Filtek P60 and Filtek Supreme, 3M Dental Products, St Paul, MN, USA). Irradiation was performed for 20s using the continuos mode of LED and Halogen light for Filtek Flow, Fitek P60 and Filtek Supreme and 40s for Filtek A110 according to manufacturers' instructions. The specimens were stored in artificial saliva for 24 hours. The monomer release was analyzed by HPLC (High Performance Liquid Chromotograph). The statistical analysis of the data was performed by Kruskal Wallis, Dunn's Multiple Comparison and Mann-Whitney-U tests using GraphPad Prisma (V3.0) software. Results: TEGDMA monomer release was detected in all material groups and UDMA was detected in the group of Filtek Supreme. The monomer (TEGDMA and UDMA) eluted ranged from 0.96 to 20.76 µg for LED and from 0.62 to 15.03 µg for Halogen. Significantly high amount (p<0.05) of TEGDMA monomer release was obtained in LED than Halogen group. Although samples cured with Halogen released less UDMA monomer than LED, no significant differences (p>0.05) found among the groups. Conclusion: The data has demonstrated that light curing affects on elution of leachable components; lower output curing light device may cause high monomer release. Therefore, type of curing units have important effects in the success of restorations and in the decrease of side potential effects. This study was supported by The Research Support Unit of Istanbul University as the project no: T-198/06032003.