Effect of dispensing rate on internal void formation in restorations built with sonically activated resin composite

Abstract Internal void formation in sonically activated resin composite (SonicFill 2, Kavo Kerr, Orange, CA, USA) applied at three different extrusion force magnitudes was evaluated. Forty SonicFill 2 composite compules were divided into four groups according to dispensing method and magnitude of extrusion force as follows: No sonic energy/manual dispensing (FM) (control), sonic energy with low extrusion force (F1), sonic energy with medium extrusion force (F3), and sonic energy with high extrusion force (F5) (n = 10). For F1, F3, and F5, sonic energy was delivered using a SonicFill handpiece. For the control, no sonic energy was applied. Composites were placed into the molds and polymerized. Micro‐computed tomography scanning for intrarestoration void assessment was performed and intrarestoration void rates (%) were calculated. Data were statistically analyzed (α = 0.05). Sonic energy yielded lower intrarestoration void rates than that of the control (10.58% ± 1.74%) (p < 0.05). Intrarestoration void rates between F1 (8.11% ± 0.99%) and F3 (7.00% ± 0.95%) were similar (p > 0.05), whereas F5 (5.14 ± 0.91%) led to significantly lower void rates compared to F1 and F3 (p < 0.05). The highest extrusion force (F5) setting of the SonicFill handpiece caused the lowest internal void rates in SonicFill 2 resin composite restorations compared to those of the medium (F3) and lowest (F1) settings.