Bulk Fill Resin Composite Materials Cured with Single-Peak versus Dual-Peak LED LCUs

Introduction: Manufactures claim that recently introduced bulk fill materials (BFM) can be cured adequately in 4 mm increments. This requires adequate light energy to be transmitted through the material to ensure adequate polymerization at the bottom of the increment.

Aim: To compare the total light energy transmission through three BFMs and bottom/top (B/T) surface Vickers hardness (VH) when cured with single-peak versus dual-peak LED LCUs.

Methods and Materials: Samples (n=5) of two viscous BFMs, Tetric EvoCeram^® Bulk Fill X-tra fil^® [XF] flowable SureFil, were prepared. A conventional RBC, Tetric EvoCeram^® was used as a control. Using MARC^® RC, the irradiance delivered to top surface of samples was adjusted to 1200 mW/cm2. Samples were cured with singlepeak EliparTM S10 or dual-peakBluephase^® G2 for 10 seconds and irradiance transmitted to the bottom surface measured. Samples were stored for 24 hours, prior to VH measurements B/T VH ratios were calculated. Statistically analysed used oneway ANOVA (α=0.05).

Results: There was no statistically significant difference for B/T total energy transmission between materials except XF with EliparTM S10 (P<0.001). Total energy transmission ranged from 0.7 J/cm2 to 1.5 J/cm2. There was no statistically significant difference for B/T VH ratios between materials (P>0.05) when materials were cured with single-peak versus dual-peak LCU’s, XF>SDR>TEC>TBF. TBF alone, did not reach the generally accepted B/T VH of 80%.

Conclusions: Both single-peak and dual-peak LCU’s were equally effective for curing the studied bulk fill materials. Manufacture’s recommended total energy delivered to the top surface may not always be sufficient for effective curing.