Abstract
The purpose of this study was to compare the linear polymerization shrinkage of different restorative resin-based composites (RBCs) using fiber Bragg grating (FBG) sensors. Five RBCs were evaluated: Zirconfill® (ZFL); Aura Bulk-Fill (ABF); Tetric® N-Ceram Bulk-Fill (TBF); FiltekTM Bulk-Fill (FBF); and Admira Fusion-Ormocer® (ADF). Ten samples per resin were produced in standardized custom-made half-gutter silicone molds. Two optical FBG sensors were used to assess temperature and polymerization shrinkage. Light curing was performed for 40 s and polymerization shrinkage was evaluated at 5, 10, 40, 60, 150, and 300 s. Statistical analysis was accomplished for normal distribution (Shapiro-Wilk, p > 0.05). Two-way repeated measures ANOVA with Greenhouse-Geisser correction followed by Bonferroni′s post-hoc test was used to analyze the linear shrinkage data (p < 0.05). ZFL showed the highest linear shrinkage and ADF the lowest. Shrinkage increased for all RBCs until 300 s, where significant differences were found between ADF and all other resins (p < 0.05). Among bulk-fill RBCs, TBF showed the lowest shrinkage value, but not statistically different from FBF. The ADF presented lower linear shrinkage than all other RBCs, and restorative bulk-fill composites exhibited an intermediate behavior.
Highlights
Resin-bases composites (RBCs) are the most used restorative materials for direct restoration procedures, both on anterior and posterior teeth
The evolution of the temperature variation induced during the light curing of the resins is presented in Figure 2, reflecting a similar pattern for all tested composite resins
Thethem, results of this study showed significant differencesand of linear polymerization shrinkage between which led to the showed rejection of the null hypothesis
Summary
Resin-bases composites (RBCs) are the most used restorative materials for direct restoration procedures, both on anterior and posterior teeth. RBCs are considered materials with good physical and mechanical properties, they undergo a volumetric shrinkage between 2% to 5% during curing, proportional to the degree of monomer to polymer conversion [2]. This volumetric shrinkage induced by the polymerization is called intrinsic or total chemical shrinkage [3]. Resin composite polymerization comprises a pre- and post-gel phases. Stress might be negligible because the material in pre-gel state can flow from the free surfaces to the Polymers 2019, 11, 859; doi:10.3390/polym11050859 www.mdpi.com/journal/polymers
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.
