Dental hygiene giant Crest announced this week that it will remove microbeads from all its products by March of 2016.

The tiny bits of plastic, which are actually an aesthetic addition that give toothpaste its blue color, have been raising concerns for some dentists and hygienists who say microbeads can become trapped under the gums, leading to bacterial buildup and gingivitis.

If gum infection spreads, it can cause severe periodontal disease.

Without acknowledging any harmful effects of the beads, Crest said in a statement that it would remove them due to a “growing preference” in its customer base. The majority of its products will be microbead-free in the next six months, the company stated.

Crest already offers some products without beads, but the popular Pro-Health line does contain them.

Evidence on Both Sides

The plastic used to create microbeads does not biodegrade or disintegrate in water.

Federal regulators say that microbeads are safe. And on Sept. 16, the American Dental Association made a statement announcing that it would not remove its seal of approval from products containing microbeads, citing a lack of clinical evidence.

But other dental professionals—including Texas hygienist Trish Walraven, who kicked off media buzz after writing on her personal blog that she’d seen negative effects in her patients—say that including a potentially harmful product for purely aesthetic purposes is unacceptable.

Plastic Panic

Toothpaste isn’t the only product in which polyethylene microbeads are used.

Facial washes and body scrubs often boast exfoliating beads that are larger versions of the same products found in some toothpaste.

Microbeads drew attention in this context as recently as June, when Illinois became the first state to ban them over fears that they harm marine wildlife, since they are too small to be caught by water filtration systems.

Several other states have microbead bans for a variety of beauty products in various states of development.