I'll be honest and admit that I have no idea what the "silicon" is and why it's even there.
I had nothing like this at my final fitting - just the new teeth put in and everything was okay :)
I'm fairly sure that whatever it's there for, it will only be temporary ..... maybe it's to help with the final healing etc, of the area around the implants??
The reason why I say it'll only be temporary, is that implants are designed to feel completely natural and will, eventually, feel just like your own teeth.
At the end of the day though, like Sparky says, the best person to ask would be your dentist.
Glad you've finally reached the end and hopefully, when these "silicon thingies" are removed, you'll be 100% happy with the end product :)