If the color of a prepared tooth darkens between the time you prepare it and the restoration is seated, the aesthetics of the final restoration can be impaired. This frustrating situation can be eliminated by knowing the causes of discoloration and what to do when planning treatment and prepping the tooth.
There are two processes that cause prepared teeth to discolor to a darker shade:
- Pulpal necrosis
- Chemical interaction between liquid vasoconstrictors and bacteria in the dentin tubules
Note that both processes can continue to further darken dentin weeks to months after you have seated the restoration. For more predictable aesthetic results, I learned some time ago to do the following.
Assess pulpal vitality first.
I am highly cautious when planning significant restorative treatment such as crown and bridge. Before prepping teeth, I review CBCT radiographs to make sure there are no pulpal health issues that need to be treated first. Like most dentists, I do not have CBCT imaging in my own practice, but I do have access to CBCT imaging via a collaborative relationship with a nearby specialist.
Use retraction paste instead of liquid vasoconstrictors for hemostasis.
Because the chemistry in liquid-viscosity vasoconstrictors can interact with bacteria in the dentin tubules to darken the dentin, I use retraction paste when I need hemostasis.
For me, these two seemingly simple steps are important ones when seeking optimal aesthetic results.