Do you mean forged pistons (zzp, carrillo for example)? In any case, this is an expensive repair.I believe there are updated pistons for these engines. I'm am not 100% sure as I do not have one of these engines.
Others may have a more definite answer.
For what it takes to change one you would be wise to change all 4.
And yet there is no need to change chains, stars and tensioners? I do not want to spend another $ 500 on these parts.