Methods: Three resin composites from Ivoclar-Vivadent (Ivoclar Vivadent, Amherst, NY) were measured: Tetric® Bulk fill IVA (A), Tetric Evoceram® A2 (B), and Heliomolar A2 (C). These composites were packed into a 10-mm deep metal, or a semi-transparent white Delrin® mold with a 4-mm internal diameter circular hole, or a 10-mm deep metal mold with a 2-mm radius semi-circular hole. The top and bottom surfaces were covered with Mylar strips and pressed flat using a glass slide, which was then removed. Composites (A) and (B) were exposed to a Bluephase®G2 curing light for 10-s on High, and (C) was exposed for 15-s. Immediately after light curing, the specimens were removed from the molds and the soft composite scraped away with a plastic spatula. The remaining hard composite was measured with a digital micrometer and divided by two. Ten specimens of each composite were made in each mold. ANOVA and Fishers post-hoc multiple comparison tests were used to compare the mold effect on the depth of cure.
Results: The depth of cure ranged from 1.3 to 4.9 mm depending on the composite and mold used.
Depth of Cure Thickness/2 |
|
|||
Mold Type |
Composite |
Depth of Cure (mm) |
S.D. (mm) |
Difference from ISO Mold |
Circular Semi Transparent Delrin |
A |
4.9 |
0.1 |
+81% |
Circular Semi Transparent Delrin |
B |
4.2 |
0.2 |
+83% |
Circular Semi Transparent Delrin |
C
|
3.4 |
0.2 |
+127% |
Circular Metal: ISO 4049 |
A |
2.7 |
0.1 |
0 |
Circular Metal: ISO 4049 |
B |
2.3 |
0.1 |
0 |
Semi-Circular Metal |
A |
2.2 |
0.1 |
-19% |
Semi-Circular Metal |
B |
1.9 |
0.2 |
-17% |
Circular Metal: ISO 4049 |
C |
1.5 |
0.1 |
0 |
Semi-Circular Metal |
C |
1.3
|
0.1 |
-13% |
Conclusions: Mold design had a significant effect on the depth of cure for all three composites (p<0.05). Composite (A) cured to a greater depth compared to (B) or (C). Composite (A) did not achieve a 4mm depth of cure in either metal mold when the Bluephase G2 was used for 10 seconds. Composite (B) did achieve a 2mm depth of cure in the circular metal mold.