IADR Abstract Archives
Marginal Adaptation of Aged Bulk-fill Composite Resin Restorations
Objectives: To evaluate the marginal adaptation of bulk-fill composite resins before and after thermocycling, using polarization-sensitive, spectral-domain optical coherence tomography (PS-OCT).
Methods: Standardized Class II cavities with 4 mm (enamel margin) or 6 mm (dentin margin) in depth x 4 mm in length (facio-lingual) x 3 mm in width (axial reduction) were prepared in extracted premolars. Specimens were randomized to one of three groups (n=10): SonicFill II (Kerr); Tetric EvoCeram Bulk Fill (Ivoclar Vivadent), and, as control, Filtek Supreme Ultra (3M), which was placed incrementally. All specimens were restored with OptiBond XTR (Kerr) in the self-etch mode, and composites were applied and light-cured following manufacturers' recommendations. After finishing (Sof-Lex) and storage (24 hours, 100% humidity), 160 cross-sectional PS-OCT baseline images were obtained along each restoration’s margins in increments of 25μm with 4mm (x) × 3mm (y) × 1.34mm (z) as total dimensions sampled in volume. B-scan images were analyzed using Image J, and the deepest enamel and dentin marginal gaps in each specimen were measured linearly. The samples were then subjected to 10,000 cycles of thermocycling between 5° and 55°C with a dwell time of 30 s in each bath. The same imaging protocol was then performed post-thermocycling, for the same specimens. Data were statistically analyzed using a general linear model (GLM) analysis of variance (ANOVA) and Tukey post-hoc test for pairwise comparisons (P<0.05).
Results: GLM ANOVA showed statistically significant difference in the factor “thermocycling” (P<0.05). No statistical difference was found between the composite resins tested (P=0.08). Results are summarized in the table.
Conclusions: Marginal gaps increased for all test composite resins after thermocycling. Even though not statistically significantly different, Filtek Supreme Ultra showed a tendency to outperform the bulk-fill composite resins in dentin.
Methods: Standardized Class II cavities with 4 mm (enamel margin) or 6 mm (dentin margin) in depth x 4 mm in length (facio-lingual) x 3 mm in width (axial reduction) were prepared in extracted premolars. Specimens were randomized to one of three groups (n=10): SonicFill II (Kerr); Tetric EvoCeram Bulk Fill (Ivoclar Vivadent), and, as control, Filtek Supreme Ultra (3M), which was placed incrementally. All specimens were restored with OptiBond XTR (Kerr) in the self-etch mode, and composites were applied and light-cured following manufacturers' recommendations. After finishing (Sof-Lex) and storage (24 hours, 100% humidity), 160 cross-sectional PS-OCT baseline images were obtained along each restoration’s margins in increments of 25μm with 4mm (x) × 3mm (y) × 1.34mm (z) as total dimensions sampled in volume. B-scan images were analyzed using Image J, and the deepest enamel and dentin marginal gaps in each specimen were measured linearly. The samples were then subjected to 10,000 cycles of thermocycling between 5° and 55°C with a dwell time of 30 s in each bath. The same imaging protocol was then performed post-thermocycling, for the same specimens. Data were statistically analyzed using a general linear model (GLM) analysis of variance (ANOVA) and Tukey post-hoc test for pairwise comparisons (P<0.05).
Results: GLM ANOVA showed statistically significant difference in the factor “thermocycling” (P<0.05). No statistical difference was found between the composite resins tested (P=0.08). Results are summarized in the table.
Conclusions: Marginal gaps increased for all test composite resins after thermocycling. Even though not statistically significantly different, Filtek Supreme Ultra showed a tendency to outperform the bulk-fill composite resins in dentin.