Does Aetna insurance cover gingivectomy?

Call the Customer Service number on your card. It depends on the level of coverage you have.

May also depend on whether your dentist deems the procedure cosmetic or medically necessary.

First do you have dental coverage,
And even if you do there are many plans, your dentist should be able to call and get confirmation of coverage for specific medical codes

Your dentist should be able to send a predetermination on your behalf to your insurance provider. They will then let you know if and how much of the anticipated fee will be paid by them.