If Veneer Comes off During Cavity Repair, Does the Tooth Have to Be Crowned?

If the cavity is small, then sometimes a filling can be placed at the edge and below some of the veneer.  Your dentist is just giving you "the worst case scenario", just as any surgeon or anesthesiologist would give you the risks and complications.

It may be very well possible that you won't need a crown.  Many times one can make a veneer that covers over more of the problem area without doing a crown.  And I do agree with you, if it was my own front tooth I would rather have a veneer than a crown.

You can still have a veneer placed after repairing the decay with a bonded filling... but it may not be the best solution.  Keep in mind that a veneer is basically a 3/4 of a crown (all-porcelain crown).  Veneers are more conservative than a crown when preparing a tooth without any fillings for a cosmetic enhancement. However, when a tooth is structurally compromised, such as those with large fillings, a crown is the restoration of choice.  Again, the visible aspect of a crown or veneer are identical since their composition is identical... if the same porcelain is used - and it should be.  Empress, e.max or feldspathic porcelain are cosmetic materials popular today.  Porcelain fused to metal crowns are falling out of favor. Regardless of the restoration you chose, be sure to discuss your diet with your dentist and try to determine what caused the decay.  Recurrent decay can happen to crowns or veneers... it is important to determine the source (usually sugar in diet) in order to prevent further issues.

Hank D. Michael, DMD - Cosmetic Dentist in Sarasota, FL

You may not have enough tooth structure after all the decay is removed to support a veneer. Your dentist should be able to make a crown match your existing veneers.