Methods: Human dentin and bovine enamel surfaces were polished with 600 grit SiC paper, rinsed with water, and air-dried. VF was then bonded directly to dentin and enamel substrates without further surface treatment following manufacturer’s instructions. A bonding jig having a mold with an internal diameter of 2.38mm was used. The shear bond strength was tested on an Instron mechanical tester after the bonded specimens (n=6) were stored in de-ionized water at 37C for 24 hours, 1 week, 1 month, 3 months, and 12 months.
Results: ANOVA analysis revealed that there are no statistical differences (p > 0.05) among the dentin bond strengths at all storage times. The enamel bond strength after 12-month storage time is not statistically different (p > 0.05) from that after 24-hour storage time, but significantly higher than (p < 0.05) those after 1-week, 1-month, and 3-month storage times.
|
Shear Bond Strength, MPa |
|
Storage Time |
Dentin |
Enamel |
24 hours |
22.8±3.1a* |
23.8±1.8ab* |
1 week |
20.5±2.3a |
21.4±1.7b |
1 month |
25.0±5.2a |
19.3±5.4b |
3 months |
20.6±4.0a |
20.1±3.4b |
12 months |
26.1±4.4a |
28.1±4.3a |
*Means with the same letter within the same column are not statistically different
Conclusions: The bond strength of VF to both dentin and enamel substrates is very stable and not negatively affected by 12-month storage time in water.
Keywords: Adhesion, Dental materials, Dentin and Enamel
See more of: Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms