Micro-computed tomography evaluation of internal void formation of bulk-fill resin composites in Class II restorations

摘要

The aim of this study was to quantify the internal void volume formation in bulk-fill resin composites with using 3D micro-computed tomography (mu CT). Class II box cavities in 4-mm depth were prepared and treated with Clearfil S-3 Bond Plus (Kuraray Medical). Five resin composites were evaluated: one conventional paste-like (Filtek Ultimate Universal Restorative-as the control), one conventional flowable (Filtek Ultimate Flowable Restorative), two flowable bulk-fill (Voco Extrabase, SDR), one paste-like bulk-fill (Filtek One BulkFill Restorative). Resin composites were light cured using a light-emitting diode light-curing unit (SDI Radii Plus, SDI Limited, Australia). Samples were evaluated by mu CT, and data were imported into software The NRecon (ver. 1.6.10.4, SkyScan) and CTAn (ver. 1.16.1.0, SkyScan) for 3D reconstruction, from which the percentage of void volume was calculated. Data were analyzed using the Kruskal-Wallis test and the Mann-Whitney U-test at a significance level of 5%. All restorative tested materials showed different levels of voids. Filtek One BulkFill Restorative showed the least void formation, which was statistically less than that of the conventional flowable composite group (p < 0.05). All other restorative materials showed similar void formation. POLYM. COMPOS., 40:2984-2992, 2019. (c) 2018 Society of Plastics Engineers