Here's a clinical case where the lower second molar needs a crown, the first molar needs a DOB, and the upper first molar needs an MOL.  EVERYTHING we teach in level 3 is how to leverage your milling time with the prep time of other teeth in the same quadrant, or even opposing quadrant. So let your mind expand a little and think of the following approach:

Get the milling machine going before you prep anything else!

Here's what I did:  Crown prep ONLY the second molar and get that milling.  While that is milling, NOW prep the first molars (upper and lower). 

Next comes the crown try-in.  With no contact to the first molar, it is an easy try in!

While the emax is Chrsytalizing, restore the upper molar with direct composite

Get ready to bond- but first do double hygiene check and give patient a break

Seat second molar.  Again very easy as there is no contact.  Clean up is supper easy

Now place section matrix band and restore the first molar's DOB

from anesthesia to dismissal was 75 minutes for a Crwon and 2 class twos, with a 15 minute break in between for hygiene checks.  That is what we do at cerecdoctors: teach you all the efficiency and time management to make CEREC a productive, quick, and easy process for you and your patients.  Join us for the fun ride!

That's the way I would have done it except it would have been about 90 min for me as I talk too much. This does make for a very efficient devlivery of a crown and the other resotrations and the patient does not have to come back to seat a crown. Question: on a second molar, how much characterization are you doing?