Should my Root Canal last forever?

Patients ask me every week why did that dental procedure they had fail by the other dentist. When I explore the question further, it may be a filling placed 10 years ago, a root canal done 15 years ago, a crown that got decay below its margins done 13 years ago, or any number of procedures done by me or another dentist.
I then ask what in their body is as good as it was 10-20 years ago. All body parts are in a state of failure. Nothing lasts forever. A new hip or knee may only last 5-10 years. The mouth is a very difficult area to survive in. The mouth has extremes in temperature daily. Drinking fluids that are 40 degrees colder than ambient mouth temperature. Or drinking or eating stuff that is hotter than ambient temperatures. This sometimes happens many times during one meal!! The expansion and contraction caused but radially variant temperatures causes stress on dental materials.

Additionally, the mouth is a wet damp place, and materials and procedures must follow strict protocols to allow the material to adhere to the tooth so that it gets its maximum life expectancy. The dental procedures are also exposed to forces that can exceed their limit of material strength. People that grind or clench notoriously break teeth, fillings, and most any dental device placed in the mouth. Also, many patients have missing teeth or rotated teeth which place loads on teeth that are at angles that cause shear forces beyond their capacity to absorb.
So my rule of thumb for most procedures, unless specifically informed of a reason for less time, is at least a decade. I want to do work that lasts at least that long and most times longer. I always think of my brand new car that I loved and was new and shiny when purchased. After 150,000 miles or 10 years, I have many fond memories, but there are certainly scratches, dents, and certain failing parts I have learned to accept because of the age and wear and tear on the car. Teeth and dental procedures are no different. If you maintain your teeth as if it was a prized vehicle, garage kept, and never driven hard, they will last a very long time. If you “ride” your teeth hard then you will get less time and use from them. It’s just a natural law of cause and effect.
Make sure you have a good relationship with your dentist so he/she can discuss all these parameters before the procedure so you know exactly why you need it and how long it will last you.