my dentist told me that whitening toothpastes just contain ingredients that only scrub off surface stains, and can wear down enamel eventually. bleaches are better because they penetrate the surface. supposedly it’s better to just bleach occasionally and then use a sensitive toothpaste every day.
however, I’m actually confused about the toothpaste thing. from what I unserstand, silica is the ingredient that provides the stain-scrubbing benefits. when I started comparing labels, I saw that they literally all have it — even ones that do not advertise to be a whitening product.