Replace Second Molar with Wisdom Tooth or Implant?

It is not easy to move a third molar into the second molar position, if the third molar is in optimal position as to move it, you might think about it but it definitively would take a long time to do and the probability of it to ideally placed is not very high.

On the other hand a implant can be done in a very predictable manner and within 4 months you can have a "new" second molar that is working properly and within this time the upper molar should not extrude.

Statistically you do 80% of your chewing on your first molar and 20% of your chewing on your second molar.  Once lost, the opposing second molar tends to migrate out of it's normal position and can become problematic.  If you are in your teens and your wisdom teeth have not fully come in, it is possible to transplant a still forming wisdom tooth into the lost second molar position.  If you are past your 20's, an implant would be a safer alternative.