How long is it OK for temporary veneers to stay on?

Hello

No, temps will help reshape the gums and if you want to make any changes to the final design now is the time to make any decision before jumping into the finals

It is certainly not ideal to have temporary veneers on this long.  If this is the case, make sure your dentist is monitoring the temps to make sure no decay or leakage is occurring; and that the health of your gums after crown lengthening is not being affected by the temp. veneersSteven M. Goldy, DDS

Usually veneer temps are typically connected together so that they stay on the teeth more predictably. Because of that, it's more difficult to clean in between your teeth. It's not ideal to have temps on for that long a period of time. Usually, after crown lengthening you'll need to have the teeth reprepared due to the changes made to the gums around the teeth. This would necessitate making new temps. I would speak to your dentist and see what the next step indeed would be.