Pacifiers latex vs. silicone?

Hi there. I bought some pacifiers the other day and i bought silicone kind. I totally spaced out and didn't realize it. Are there any differences? Dangers? Is it because some babies are allergic to one or the other? Please help, I need to know if i need to return them. I don't know anything about my son with them because he hasn't graced us with his presence yet. :)