Case Study – 2 Stories About Cracked Teeth
Case 1 – Initial Situation
This lady presented with pain to chewing in 2012 on her lower left second molar.
This tooth had been restored when she was a teenager with amalgam.
As this tooth comes into contact with the opposing teeth, it flexes and the metal restoration flexes at a different rate than tooth. The integrity of the tooth is already compromised from the very fact that a restoration had to be placed in there in the first instance.
This patient also happens to be a bruxer. With the high levels of parafunctional force applied to the tooth and for the reasons outlined above, cracks develop through the tooth. As the crack grows it can become symptomatic.
The Treatment Plan
At the time we placed a composite restoration. This is a very conservative approach and cost effective. The advantage of a composite restoration over amalgam is that it flexes at a similar rate to tooth and so can be active in crack propagation. The patient was delighted when symptoms resolved.
Unfortunately, the symptoms returned in 2014. At this time we place a ceramic overlay using our cerec system. Symptoms did not resolve in this case.
We referred to our local endodontist (Gary Verdickt Sutherland), he noted that the crack had migrated through the pulp chamber floor which we term a vertical root fracture. This has a hopeless prognosis 3+.
This is the worst case scenario. In the vast majority of cases the placement of a ceramic overlay will prevent the crack from propagating further and ensure the survival of the tooth. In the above case, there is a strong likelihood that if a ceramic overlay had been placed in the first instance, then the tooth would still be functioning for this patient.
We do not suggest a ceramic overlay for every crack we see around an amalgam restoration. However, when they become symptomatic early intervention with the most appropriate ceramic overlay designed cadcam and milled with our in house Cerec Omnicam is the best course of action.
Case 2 – Initial Situation
Here the last tooth in the arch takes the most force. Again the patient is a bruxer and exhibited significant damage to his front teeth.
Cracking and symptoms around the amalgam in the hindmost tooth in the arch where the greatest force is applied.
The Treatment Plan
We reduce the biting surface by about 1.5mm and remove the existing amalgam. We can see the crack still present. We do not try to remove the crack as this would involve removal of too much tooth structure. The aim of this type of cermic overlay is to retain as much tooth structure as possible while still taking the pressure off the crack.
We cement a ceramic overlay which blends to give an imperceptible margin with the underlying tooth structure.