Should I Chomp Down with Invisalign?

The aligners are there to move teeth and change your bite. Dont try to overide them by biting down. Plus you are on aligner number 2 so you are just getting started. Calm down and let the aligners work...

Every force (action) has an equal and opposite reaction.  If you are clenching, although unlikely, you may alter the possition of the teeth.  I would be a little more worried that you are over developing the "clenching" muscles and when you are done with treatment you have a new habit of clenching.  Without the trays, clenching is much more likely to move the teeth as well as potentially wearing them down and developing cracks in them.  So I say stop clenching.

During the process of tooth movement with invisalign your teeth are going to be moving and your bite will be changing. This process happens slowly and over time your teeth, your bite, and your muscles will all adjust to the new tooth position and bite.

I would not recommend clenching your teeth.  I would recommend wearing your invisalign trays  the 21-22 hour/day time prescribed by your doctor so that your teeth move most effectively.  The proper wear time will also allow your aligners to fit best.  I would let invisalign work as this is only your second tray and you are still getting used to the feel of invisalign and your new aligner. You must realize that changes in your tooth position and bite are a normal part of this process.

Invisalign trays will often alter how things feel.  The bite will seem different and some aligners will seem tighter than others.  Let the trays do their job and all should be well.  If you try to "help things along" the aligners may crack and not work anymore.

Clenching into trays is not necessary or desired.  Just allow the trays to do their thing by themselves.  It is very common during orthodontic treatment to have the bite feel somewhat off as they transition from one position to another.  This may in fact happen over and over again with each tray.  Don't worry it is normal.  It will all work out in the end!