Every brand of feeding bottles has its specific teat/ nipple. It is advisable to change the teat regularly for hygienic purposes.
Basically, there are 2 materials commonly used for teat: silicone and latex. Latex has a softer texture compared to silicone, but the latex requires to change more frequently.
On the packing, there is an age recommendation for your reference. Shall your baby drink a bottle of milk for more than 10 minutes, then change to the next step.