I'd probably sterilise the bottles and buy new teats. But thats only because I wouldn't know if they had formula in those bottles

(I hope this doesn't read like I'm against formula, I'm not, I formula fed 3 of mine and only successfully breastfed my last child out of all of them. So I'm not against any way of feeding LOL)
Even if you were I wouldn't even know! I think I was a formula baby after 2 months, mum had a bit of trouble. The teats look in good condition, maybe I will check out some new ones

I've used the calma teat for DD2. What would you like to know?
I just went on to the Medela website and researched the calma teat. I just didn't know what it was for And actually, I'm still not 100% sure.....