Table 2.
Grading results of the dentin bridge formation following the criteria of pulp histological consecutive sections 4 weeks after direct pulp capping (n = 6 per group).
| Grade | Dentin bridge formation | |||
|---|---|---|---|---|
| Material | 0 | 1 | 2 | 3 |
| Digested DMCs (MMP-1)* | 1 | 2 | 2 | 1 |
| Digested DMCs (MMP-2) | 5 | 1 | 0 | 0 |
| Digested DMCs (MMP-3) | 5 | 1 | 0 | 0 |
| Digested DMCs (MMP-8) | 5 | 1 | 0 | 0 |
| Digested DMCs (MMP-9)* | 2 | 2 | 1 | 1 |
| Digested DMCs (MMP-13)* | 2 | 1 | 2 | 1 |
| Digested DMCs (MMP-20)*,** | 0 | 0 | 4 | 2 |
| Incubated DMCs without MMP | 3 | 2 | 1 | 0 |
| PBS | 6 | 0 | 0 | 0 |
*1 µg/ml of DMCs treated with MMP-1, MMP-9, MMP-13, or MMP-20 stimulated pulp tissue repair, compared with 1 µg/ml DMCs treated with other MMPs. **In particular, 1 µg/ml of DMCs treated with MMP-20 resulted in significantly increased tertiary dentin formation, compared with all other MMPs. DMCs: dentin matrix components, PBS: phosphate-buffered saline; MMP, matrix metalloproteinase.