People wear silicone rings for a variety of reasons. Some think they're more masculine, but fields that require a level of physical contact or risk of injury (law enforcement, woodworkers, etc) err on the side of caution in the event their hands get busted up. The swelling would make it impossible to get them off and can lead to serious problems, like lost fingers yay.
Some metals like Titanium, etc, have come into more common use and an ER tech would need the appropriate tools to remove. For a while, those tools weren't as readily available, so it was better to use a softer metal (or just wear silicone at work).
None of this applies to Nick unless he's shoving his fingers in places that can fuck up his hands.