My dentist recommended Crest Sensi-Stop Strips, but the package says not to use during pregnancy/breastfeeding. I'm currently breastfeeding, so I emailed Crest and they said they were safe to use during breastfeeding. Thoughts? They work similar to the white strips (leave on a small area for 10 mins, once a month)

Ingredients are: Aqua, Glycerin, Cellulose Gum, Dipotassium Oxalate, Carbomer, Sodium Hydroxide, Sodium Benzoate, Potassium Sorbate.