The Dentist ground down my good tooth!

I hear this from my patient’s every day. They point to a tooth or refer to a previous dentist that “drilled on a good tooth”, so that must be the reason for the problems they are having.
I understand that sentiment 100%. I would think and feel a similar way if I was a patient and if I was not fully informed why the dentist “ground down” a good tooth. And when I say fully informed, I do not mean informing the patient that they need a different tooth smoothed down. I mean really getting the patient to understand that, most likely, the tooth that needs to be “ground down” is ultimately the villain or the cause of the other tooth problems. Let me explain further.
When a tooth breaks or is cracked, a dentist must look for the reason. Many times it is simply that the patient bit on something harder than the tooth and the tooth broke. But frequently, the reason the tooth broke is because the opposing tooth is stronger and has a very pointy, chisel-like cusp that exerts too much point contact pressure. Think of the chisel-like cusp as a log splitter. It is hitting the tooth hundreds a time per day and eventually a small crack develops and increases until the tooth either breaks or hurts to chew on it.
In those situations, a dentist MUST smooth the opposing tooth(“Grind on a good tooth”) or the new crown/filling will be under the same stress and will break just like the natural tooth. So the simpliest solution is to smooth the offending cusp and recreate a situation where the new crown will be under normal biting forces.

Please remember, nothing in the mouth happens without a reason. If a tooth hurts, is rotated, has red gums and or a myriad of other problems, something is causing the issue. Our job as a dentist is to figure out the cause and re-mediate it as best we can so the patient can function normally.