in vs over in present perfect tense

Over has to be used with a specific span of time.

I've been to the dentist quite a few times over the past few days. There were many battle casualties over the centuries.

In can be used my flexibly.

I've been to the dentist quite a few times in my life. The eye has evolved quite a few times in history.

You cannot substitute over in these examples.

Wrong: I've been to the dentist quite a few times over my life.

Wrong: The eye has evolved quite a few times over history.

You'd have to substitute or add a span of time to use over in these examples.

Correct: I've been to the dentist quite a few times over the decades of my life. Correct: The eye has evolved quite a few times over the aeons of history.

In your example, you can use either, but they expressing slightly different things.