IADR Abstract Archives
Reduced curing time affects color change for dental composites.
Objectives: Color change in service may lead to unacceptable esthetics for dental composite restorations. The hypothesis to be tested was that for a dental composite, there is an inverse correlation between degree of conversion (DC) and color change when aged in staining solutions. Three different types of composites were exposed to four different levels of curing energy to produce well and under-cured materials, and the color was assessed after aging in three different solutions for 24 weeks.
Methods: Filtek Supreme Ultra (3M ESPE), TPH Spectra (Dentsply Sirona), and Tetric EvoCeram (Ivoclar) were compared. Five disk-shaped specimens (8 mm diameter by 2 mm thick) of each composite for each curing time (5, 10, 15, and 20 sec) were prepared in vinyl polysiloxane molds. Specimens were light activated directly through a clear matrix (Demi Plus, 11 mm guide, 670 mW/cm2; Kavo Kerr) directly on the top surface. Specimens were polished using the Enhance/Pogo system (Dentsply). DC was measured in near-IR after 24 hours. Then initial color measurements were made before specimens were soaked in staining solutions of water, red wine and coffee at 370C (solutions changed every two weeks). Color was re-measured at 24 hrs, 1, 4, and 24 weeks with a Spectrophotometer (CM-700D, Konica), and Delta E00 was calculated. Results were analyzed with ANOVA/Sheffes and Pearson correlation (α=0.05).
Results: DC increased linearly with curing time (p≤0.05), except for Spectra (10s=15s; 15s=20s). All composites showed increased color change with time, most noticeably in wine and coffee (Figure). There was a significant correlation (p≤0.05) between reduced delta E00 and increased DC (p≤0.05) for all composites/solutions, except for Spectra and Tetric in water.
Conclusions: This study verified that undercuring dental composites can lead to enhanced color change during aging, which may be especially important for patients who routinely drink beverages with high staining potential.
Methods: Filtek Supreme Ultra (3M ESPE), TPH Spectra (Dentsply Sirona), and Tetric EvoCeram (Ivoclar) were compared. Five disk-shaped specimens (8 mm diameter by 2 mm thick) of each composite for each curing time (5, 10, 15, and 20 sec) were prepared in vinyl polysiloxane molds. Specimens were light activated directly through a clear matrix (Demi Plus, 11 mm guide, 670 mW/cm2; Kavo Kerr) directly on the top surface. Specimens were polished using the Enhance/Pogo system (Dentsply). DC was measured in near-IR after 24 hours. Then initial color measurements were made before specimens were soaked in staining solutions of water, red wine and coffee at 370C (solutions changed every two weeks). Color was re-measured at 24 hrs, 1, 4, and 24 weeks with a Spectrophotometer (CM-700D, Konica), and Delta E00 was calculated. Results were analyzed with ANOVA/Sheffes and Pearson correlation (α=0.05).
Results: DC increased linearly with curing time (p≤0.05), except for Spectra (10s=15s; 15s=20s). All composites showed increased color change with time, most noticeably in wine and coffee (Figure). There was a significant correlation (p≤0.05) between reduced delta E00 and increased DC (p≤0.05) for all composites/solutions, except for Spectra and Tetric in water.
Conclusions: This study verified that undercuring dental composites can lead to enhanced color change during aging, which may be especially important for patients who routinely drink beverages with high staining potential.
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