IADR Abstract Archives
Effect of Solvent-Storage on Visco-Elastic Creep of Ultra-Fast-Photo-Cured Resin-Based Composite
Objectives: Investigate the effect of solvent-storage on the visco-elastic creep and recovery behaviour of an ultra-fast-photo-cured resin-based composite (RBC) compared to conventionally irradiated RBCs.
Methods: Three bulk-fill RBCs were studied: Tetric® PowerFill (ultra-fast photo-polymerized composite) (TPF), Tetric EvoCeram® (EVO), and GrandioSO® x-tra (GSOx). Cylindrical-shaped specimens (n=3) were prepared from each material using stainless steel split moulds (4 mm × 4 mm). TFP specimens were irradiated from all sides with a Bluephase PowerCure unit at 3200 mW/cm2 for 3 s, while EVO and GSOx were irradiated with an Elipar S10 unit at 1200 mW/cm2 for 20 s. A creep measurement apparatus connected to a small water bath was used to determine the creep/recovery behaviour under wet conditions. Each specimen was loaded (20MPa) for 2 h to measure the creep and unloaded for 2 h to measure recovery. The strain deformation was recorded continuously for 4 h. Measurements were taken after 24 h of preparation (baseline), and then after 30 days of storage in 75% ethanol/water (75% E/W). Statistical analysis was performed using one-way ANOVA and an independent t-test (α=0.05).
Results: At the baseline, the maximum creep strain % ranged from 0.22% to 0.46%, and after solvent-storage, the range increased from 0.73% to 1.2%. Also, the permanent set ranged from 0.03 % up to 0.06 % at baseline and from 0.18 % up to 0.37 % after solvent-storage. Dependent on the material and storage condition, the percentage of creep strain recovery ranged between 69% and 91%. Increased filler loading in the bulk-fill materials decreased the creep strain magnitude.
Conclusions: Creep deformation of all studied RBCs increased with solvent-storage. Ultra-fast-photo-cured RBC exhibited an acceptable creep strain and recovery and was within the range of other conventionally irradiated RBCs after solvent-storage for 30 days.
Methods: Three bulk-fill RBCs were studied: Tetric® PowerFill (ultra-fast photo-polymerized composite) (TPF), Tetric EvoCeram® (EVO), and GrandioSO® x-tra (GSOx). Cylindrical-shaped specimens (n=3) were prepared from each material using stainless steel split moulds (4 mm × 4 mm). TFP specimens were irradiated from all sides with a Bluephase PowerCure unit at 3200 mW/cm2 for 3 s, while EVO and GSOx were irradiated with an Elipar S10 unit at 1200 mW/cm2 for 20 s. A creep measurement apparatus connected to a small water bath was used to determine the creep/recovery behaviour under wet conditions. Each specimen was loaded (20MPa) for 2 h to measure the creep and unloaded for 2 h to measure recovery. The strain deformation was recorded continuously for 4 h. Measurements were taken after 24 h of preparation (baseline), and then after 30 days of storage in 75% ethanol/water (75% E/W). Statistical analysis was performed using one-way ANOVA and an independent t-test (α=0.05).
Results: At the baseline, the maximum creep strain % ranged from 0.22% to 0.46%, and after solvent-storage, the range increased from 0.73% to 1.2%. Also, the permanent set ranged from 0.03 % up to 0.06 % at baseline and from 0.18 % up to 0.37 % after solvent-storage. Dependent on the material and storage condition, the percentage of creep strain recovery ranged between 69% and 91%. Increased filler loading in the bulk-fill materials decreased the creep strain magnitude.
Conclusions: Creep deformation of all studied RBCs increased with solvent-storage. Ultra-fast-photo-cured RBC exhibited an acceptable creep strain and recovery and was within the range of other conventionally irradiated RBCs after solvent-storage for 30 days.
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