Is it OK if use silicone shield 24/7? Can I just take it off to shower? On a tummy tuck scar?

Yes.  Not only can you wear silicone gel sheeting 24/7 other than while showering but you should.  It is most effective when worn almost continually over a scar for a few months.

Surgeons often have different opinions so it's probably best if you discuss this with your own surgeon but if you are not having any side-effects of having the silicone strips on then there is probably no issue wearing them all the time except to shower. Hope that helps! 

Hello, usually there is no harm wearing the silicone strips continually (except for showering/hygiene), as long as there is no underlying skin irritation or maceration.  

This is fine but you have to be careful you don't develop a contact dermatitis in which your skin will get red and itchy.

I think you need to ask your surgeon, Dr Pena, if OK to do this. I would allow if you were my private patient.