Abstract
Objectives The aim of the study was to determine the quantitative and qualitative surface structure of contemporary RBCs in posterior teeth reconstructions: regular viscosity bulk fill and conventional composites, obtained after two-stage polishing procedure. Materials and Methods Four conventional nanohybrid composites (Tetric EvoCeram, GrandioSO, Filtek Z550, and Ceram·X Mono) and four regular viscosity bulk fill composites (Tetric EvoCeram Bulk Fill, X-tra fil, Filtek Bulk Fill Posterior, and QuixFil) were tested. Samples of each RBC were prepared using PMMA cylindrical mold. After two-step polishing procedure, a surface geometry was evaluated under profilometry (Turbowave v. 7.36, Hommel-Etamic) and SEM (VEGA 3, Tescan Analytics). To evaluate differences between values, the following nonparametric tests were used: Friedman's ANOVA, Wilcoxon's matched-pair test, ANOVA Kruskal-Wallis, and Mann-Whitney U. Results All conventional RBCs showed Ra values in the range of 0.20-0.26 μm. Bulk fill showed higher values in range of 0.49-1.36 μm except for Filtek Bulk Fill Posterior, which achieved 0.23 μm Ra value. SEM images of conventional RBCs were described as smooth surfaces with slight damage except for TEC, which presented smooth surface with no damage. Bulk fill composites showed rough surface, except for TBF, which presented smooth surface with slight damage. Conclusions Regular viscosity bulk fill composites do not constitute a homogeneous group regarding surface roughness after polishing. They obtain, for the most part, poorer smoothness values after polishing than conventional RBCs.
Highlights
Finishing and polishing of resin-based composites (RBCs) is a necessary procedure which allows to obtain high-quality and esthetic filling [1,2,3,4,5,6,7,8,9,10]
Due to the need of polymerization shrinkage reduction, often contain large, irregular filler particles in their structure, which can suggest worse polishability compared to conventional composites
The SEM image of Tetric EvoCeram Bulk Fill is similar to the image of Tetric EvoCeram, but with less frequently spaced large and irregular filler particles among very fine ones
Summary
Finishing and polishing of resin-based composites (RBCs) is a necessary procedure which allows to obtain high-quality and esthetic filling [1,2,3,4,5,6,7,8,9,10]. According to St-Pierre et al, material-dependent factors that affect surface roughness are (1) the resin matrix content and formulation, (2) the filler particle characteristics (type, hardness compared with the abrasiveness of the polishers, size, and shape), (3) the composite resin filler load, (4) the quality of the silane coupling agent, and (4) the degree of conversion after light. In contrast to conventional composites, which require incremental placement, these materials contain more sensitive photoinitiators that allow the depth of cure to reach up to 4-5 mm while maintaining predictable degree of conversion [23, 24] This would allow dentists to place a single increment in deep lesions without the need for a layering technique expediting the restorative procedure and decreasing the overall chair time [24, 25]. Studies comparing the roughness of bulk fill and conventional composites are very limited [5, 11, 30, 31]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
