Can a Crown Be Reshaped?

I agree with Dr. Lockhart.  Crowns can be reshaped for minor changes, but major changes are not so easy.  It depends on the type of crown that was placed as well.  If you are flattening the front surface of the crowns it makes the porcelain thinner.  On a porcelain to metal crown this will expose the more opaque porcelain layers or even the metal substructure and make it look even worse.  You might be able to try this if the crowns are all-ceramic crowns.  Even these are often more opaque toward the core.

It is also difficult to get a highly polished surface when polishing in the mouth.  It can be done though.  I would say try to contour with the idea in mind that if it doesn't work, the crowns will be redone.  This is your smile, and you are a walking billboard for your dentist.

It is possible to re-shape a ceramic crown, however the question that needs to be addressed is whether the re-shaping will result in a lower glaze that may not be cosmetically pleasing.  If to much reshaping is necessary, it may be a wiser alternative to have the crowns remade.  Make sure that you discuss your concerns with your dentist so that communication with the lab is correct.

It is far easier to round off a flat or squared area than the reverse.  Said another way, it is easier to remove a little material than put it back.

It is critical that the lab technician consider the contours of the adjacent teeth when designing a veneer or crown so they are mimicked accordingly.  In our office we always try the restorations in and have the patient examine the look in a mirror prior to permanent cementation.  In some aesthetic cases we may place the restorations with a temporary adhesive so the patient can have their spouse or partner get a look before making things permanent.

You probably will need to have the crowns removed and replaced.  If you have a picture of the former veneers or a dental study model that includes the veneers in place, the lab can use them to make a more accurate reproduction.  You can also have the dentist place and modify temporaries until you get the desired aesthetic result, take an impression of the temporaries and have the lab use that information to duplicate the look in the new crowns.

they can be contoured with diamond drills, but this will not change the tranluscency and might make them worse.

I would do them over again and go see the ceramist at the dental lab face to face. Tell  him what you want. Make sure you are happy with the shape of the temproary crowns first. Then photo graph them and take a mould of them for the lab to copy in the design of the permanent crowns.

Yes Crowns can be reshaped. However, it is nicer if the crowns are reshaped prior to permanent cementing. This way, if a good deal of reshaping is performed, the vrown can be sent back to the lab and re-glazed to give it the natural appearance that it originally had prior to reshaping. We can polish the crown after reshaping and it will look good, but sending to the lab for re-glazing is best.

Minor reshaping is common on crowns and not a problem in most cases.  If removing some of the 'over roundness' helps the new crowns match you existing teeth, then yes reshaping is the best solution.  Your dentist can easily manage this and polish the porcelain to a high gloss again. Of course, some additional concerns apply to metal based crowns - although the great majority of anterior crowns are all-ceramic in 2011.

The only problem is if the new crown needs 'extra' porcelain to match the surrounding natural teeth.  In this situation, the crown needs to be removed and remade.

I would ask your dentist about your new crown and have him/her evaluate your concerns.  I'm sure you will be happy in the end by honestly discussing the issues you have with th shape of the new crown.