You can totally add a couple of drops of silicone in it. As for it breaking because it is plastic? I don't know. I do know that I have made a dozen fills and there is no breaking whatsoever, so far anyway. I just wanted the community to know that there is a cheap alternative out there and that it may not even cost you anything. I'm sure no one would just buy the teeth whitening syringes just for the tip. If you wanted to buy something, Jugglez's and Madmax's adapters work perfectly fine and I do use both of them
