[PS4] Disc replacing

Hi there, i am playing this awesome game about 1 month :)
This is my first post here and i hope wont be the last one.
Anyway, i have PS4 and i bought ARR on the DISC BLURAY, everything fine, but i want to ask you if my disc will be scratched and totally unused within time, can i buy another disc from the shop and launch the game within the new disc ? do i need register something ? or just use the new disc and play ? :)

Because on my disc i saw a totally lisstle crack from the inside circle of the disc this plastic thing, not reading layer, and i am thinking it will explode in console ? its just like a dot crack not a big one ... My english its not good, but i hope you will understand me and help me out :)

Cheers all !! :)

I was under the impression that you didn't need to insert the disc to play (after the first time). Is that not the case?

I must put my disc everytime i want launch ARR :(
first time i put disc = install + launch
everytime now = launch

Well thanks for the reply :)

i think i must buy digital one :(

There's is no problem with using differente copies of the game, the games launches with your account infomtion, not the information in the disk, therefore, your disk only contains what's realted to the game itself not your personal information and account. So if your disk goes bad you can always get a new one and it will work on your existing account.