Objectives: Bond strengths (BS) of two self-adhesive resin cements (RelyX Unicem 2 Automix, RU2; SpeedCEM, S) to human ground enamel (GE) and dentin (D), zirconia (Lava, L) and lithium disilicate (IPS e.max CAD, EC) were tested. Methods: Specimens of GE, D, L, and EC were ground through 600-grit SiC paper. L was then sandblasted with 50 μm alumina. EC was treated with HF gel etchant for 20s, rinsed, and then ceramic primer (Monobond Plus) was applied. BS was tested using indirectly cemented cylinders of composite (TPH3) with the Ultradent shear BS test method. Both light-cured (LC) (Demi LED) and self-cured (SC) modes were evaluated. Both cements were protected from oxygen inhibition during SC by a coating (Oxyguard II). Testing was performed after 24h storage in water at 37°C. Data were analyzed statistically using analysis of variance and Fisher's PLSD at the 0.05 level of significance. Results: Means and standard deviations are shown in the table. Data were analyzed by analysis of variance at the 0.05 level of significance. Means with the same letters are statistically the same.
Cement | Cure | Substrate | Bond Strength, MPa |
RU2 | LC | GE | 17.5(3.1)d |
S |
|
| 13.6(1.6)b |
RU2 | SC |
| 10.1(1.6) |
S |
|
| 14.7(3.4)be |
RU2 | LC | D | 18.7(1.3)d |
S |
|
| 11.8(1.4) |
RU2 | SC |
| 13.5(2.0)a |
S |
|
| 13.8(1.7)ae |
RU2 | LC | EC | 36.5(3.2) |
S |
|
| 34.1(5.2) |
RU2 | SC |
| 32.5(1.9) |
S |
|
| 28.0(5.1) |
RU2 | LC | L | 30.9(4.8) |
S |
|
| 14.1(2.7)c |
RU2 | SC |
| 17.9(2.1) |
S |
|
| 13.6(1.7)c |
Conclusions: RU2 produced statistically higher BS to L and EC than S when either LC or SC. S and RU2 had equivalent BS when SC to D. RU2 produced statistically higher BS to GE and D than S when LC. SC BS of S to GE was higher than RU2. LC BS of same cements were higher than or equivalent to SC except for S on D. Funded by 3M ESPE.