Bonding looks dull, sensitivity after bonding
Normally, dullness of the bonding is due to polishing. You should definitley go back to your dentist and relay your concern and have the bonding re polished to make it shinny.
In term of sensitivity, it can be caused by two factors:
1. Depth of the bonding and its proximity to the nerve.
2. Bite issue.
Again its best to let your dentist know right away.
Great questions--Dullness on composites can be from either finishing issues or can be related to the particle size of the glass in the composite itself. Some composites will simply dull quickly and stain as well.
The finishing is also important as if not finished to a consistent shine they will dull and pick up stains more easily
Sensitivity is another issue--this can be bite related, bond seal, or even gum line finished edges that are left too bulky or open can also contribute to sensitivity
Follow up with your dentist to give them a chance to redress.