Knees are wearable items. The cartilage can wear out, but you can keep it healthy and fend it off.
Runners are at greater risk, but a single marathon won’t do it.
Teeth suffer from wear and tear, too. It’s a balance between wear and tear and overall prevention and health. Stay healthy, nourished and use good running technique, equipment and training methods and you can minimize wear and tear, or reduce the likelihood of having problems.
Good genetics helps, too.
Like anything else you do for your health, nothing is a guarantee. Running increases the risk of cartilage issues, and a healthy lifestyle can help fend it off, but neither is a guarantee of anything!