To prevent your baby from becoming too attached to one specific teat, rotate the use of 2 or more teats for about 2 months before considering replacements. If teats become worn out or are bitten, replace them earlier as needed, regardless of how many times they’ve been used. For isoprene rubber teats previously sold, they can be used for three to four weeks when two or more teats are rotated. Keep in mind that teething babies may cause faster wear and require special attention.