How do I determine whether a broken tooth was coincidence or the fault of the dentist?

[jumpin_jumpin]

On 8/17 I noticed small crack on top of tooth #29 before bed.

On 8/18 I woke up and called my dentist; they were able to see me at 10:30am At 10:30 was examined, and told that the crack was stemming from the old filling which was not uncommon. It was just a surface crack, and the tooth was structurally sound. I asked multiple times “will my tooth break off or fall out?” and was reassured that no, that would not happen. The tooth was fine. To be safe, the dentist opted to put on an overlay and redo the filling from which the crack stemmed. A temporary overlay was put in place, and the fillings were redone.

When brushing at night on 8/20, a large portion- almost half- of the tooth broke off. I had followed all aftercare instructions and been diligent in my care.

I had been reassured multiple times that the tooth was sound and fine, based on exam and xrays done before the procedures. No xrays were done after the procedures.

To go from being told "it's all sound and OK" to missing half a tooth in 2 days is alarming, and I don't know what do do next.

 

[Dr M]

Good day

A tooth can fracture if the preparation for the overlay was done in a way where a thin portion of tooth structure was left. It is also possible that the true extent of the crack could not be determined. An x-ray only give a 2 dimensional image after all. If you had quite a large filling previously, a full coverage crown might be a better option. I would go back to the dentist so that he can have look at the amount of remaining sound tooth structure that is left. Sounds like the plan needs to be adjusted.