Temporary bridge too big, can the dentist fix it before it's permanent? (photo)

When implants are placed after teeth are extracted, you will loose bone. When you loose bone, the temporaries must be made longer to fill in that new space. When you lip is down, the teeth probably look great. It is nice you do not have a smile line that shows your pink gums. You should talk to the restoring dentist about what you like about the teeth and what you wish you could change. Some of the changes may be possible. 

Yes the temporary can be corrected.  More important, don't let the dentist cement the permanent bridge until you are happy with esthetics.

Implants are similar to tooth roots but the bone (shape of your maxilla) will dictate where they can be placed.  The gums are more of a "skin blanket" that sits over the bone.  The space left between the gum and your lower tooth "bite" is the prosthetic space needing to be filled.  If when you smile, you do not show all your tooth in the front, the longer teeth will not be noticed.  If when you smile you see too much tooth, there will be other cosmetic procedures performed on your final ceramic work that can help...like adding pink gingiva colored ceramic at the gumline.  The thickness of the teeth are also there to add lip support so voice your concerns to the restorative dentist but also understand you have now a fixed prosthetic that is being made to replicate loss of part of your maxilla and the teeth that were there, it needs to be acceptable but it may never be perfect.  

Hi There,You have pulled up your lip.  How do your teeth look in your natural smile. Sometimes with bone loss and implant placement, dentist and dental labs have to make the teeth bigger.  That being said, yours look big, altho' in this picture they are seemingly a pretty good match color wise.  Like another Dr. said here, make sure you approve and see what you are getting before they are permanently cemented on your implants.  Good Luck!