Objectives:
To investigate the effect of curing durations and high vs “soft start”modes on the depth of cure of Bulk-Fill Flowable composites.
Methods:
The following Bulk-Fill materials were included: A. TetricEvoCeram (Ivoclar Vivadent); B. Surefil SDR flow (Dentsply); C. Venus (Heraeus Dental). Specimens were fabricated as cylinders ( 4mm width X 8 mm height )using the Bluephase 16i (Ivoclar Vivadent) photocuring unit with “soft-start” (SS) and high mode (HM) of curing for (10, 40) seconds. Cured specimens were longitudinally sectioned and polished. The level of curing was assessed through microhardness testing (Vickers, 100g., 25s) at depths of top, 2mm, 4mm, 6mm. Sixteen measurements for each test parameter were conducted. The results were tabulated and analyzed by ANOVA.
Results:
Percent Photocring vs. Top Layer
Depth |
2 mm |
4 mm |
6 mm |
|||||||||
Duration |
10s |
40s |
10s |
40s |
10s |
40s |
||||||
Mode |
HM |
SS |
HM |
SS |
HM |
SS |
HM |
SS |
HM |
SS |
HM |
SS |
Composite A |
105% |
99% |
95% |
102% |
93% |
95% |
92% |
98% |
83% |
99% |
94% |
107% |
Composite B |
100% |
106% |
104% |
102% |
91% |
98% |
106% |
99% |
79% |
83% |
95% |
82% |
Composite C |
119% |
106% |
110% |
103% |
124% |
103% |
116% |
103% |
113% |
99% |
114% |
107% |
Conclusions:
There was a significant difference between curing with high and “soft-start” mode (p= 0.05). TetricEvoCeram Bulk, was significantly different at 10s with the “soft-start” mode. Whereas, Surefil SDR and Venus were significantly different at 40s with high mode of curing. Photocuring duration and type of material has significant effect on the depth of cure (p= 0.05). All composites tested are capable of curing to a depth of 6 mm.