Natural vs nylon toothbrush bristles: which is better?

We sell a natural-bristle brush, so we have an obvious interest in this answer. That’s why the page gives nylon its real advantages first, and says plainly where the research runs out.

Side by side

Why nylon took over

Natural bristle had its critics long before nylon: the 18th-century French dentist Pierre Fauchard warned against horsehair toothbrushes as liable to cause damage. The first nylon toothbrush arrived in 1938, and a 2026 history of oral hygiene sets out why it won: nylon filaments were more durable and more uniform in diameter and stiffness than animal hair, took up less water, and their tips could be rounded to reduce trauma to the gums.

Those are real advantages, and they explain why nylon is the default today. A bristle made to a uniform thickness behaves much the same in every tuft. Natural hair can’t promise that.

What the research does and doesn’t show

Rounded tips matter, and nylon can have them

In a 46-person randomised trial, brushes with 40 to 50% or more of their filaments end-rounded caused significantly fewer gum abrasions than brushes whose filaments were simply cut. That’s a genuine point for nylon, with one caveat: rounding is possible, not guaranteed. A 2001 microscope study of 31 Italian brands found more than half the filaments rounded in only 4 of them.

On the natural side, a 1982 electron microscope study found that new swine and boar bristle brushes had filaments of irregular length and diameter, with deficient, irregular ends that got worse with use, while new nylon tufts were uniform. Horse hair wasn’t part of that study, so it tells you about boar bristle, not about every natural brush.

Cleaning: we couldn’t find a comparison

We searched for a study comparing natural and nylon bristles on plaque removal and couldn’t find one. Studies of “natural” toothbrushes are usually about bamboo handles or chewing sticks, not animal bristle. So we can’t tell you that one cleans better than the other.

Water and drying

Hair absorbs water and swells, and takes up water slowly. Horse hair is a keratin fibre that does the same, while nylon was adopted partly because it takes up less. We couldn’t find a measured drying time for either kind of brush, so the practical answer is the same for both: the American Dental Association advises storing toothbrushes upright to air dry.

Hygiene

Every bristle in our brush is cleaned and sterilised before assembly, and brushes arrive dry, clean and odourless. Rinse well and air-dry upright between uses and they stay that way. We cover the detail in are horse hair toothbrushes hygienic?

Plastic

This is the one row where the answer is simple. Nylon is a plastic, and research has confirmed that toothbrushes release microplastic particles in use. Natural bristle isn’t plastic, so it can’t shed plastic. We go through what the shedding research measured in do toothbrushes shed microplastics?

What dentists actually advise

The American Dental Association recommends soft bristles because they minimise the risk of gum abrasion, and the Australian Dental Association’s brushing basics list a brush with soft bristles. Neither page says anything about natural or nylon. Soft is the advice, whatever the bristle is made of.

One thing to know when you compare packs: bristle texture labelling isn’t standardised, so one brand’s soft can be firmer than another’s medium.

Which should you choose?

• Choose soft nylon if you want a more consistent bristle that takes up less water, or a vegan brush, and plastic in the head doesn’t bother you. Look for end-rounded filaments.
• Choose natural bristle if you want bristles that aren’t plastic, and you’re comfortable with an animal fibre and a little more care with drying. Horse hair is the softer natural option; boar bristle is firmer. We compare them in boar bristle vs horse hair.

Where we fit

Our brush is sterilised horse hair woven into the bamboo head, with no nylon and no glue. It isn’t vegan, because horse hair is an animal product, and there is one small aluminium staple inside the head, which doesn’t compost. If nylon suits you better, a soft, end-rounded nylon brush is a perfectly good choice, and we’d rather you knew that.

The short version

• We couldn’t find a study showing either cleans better.
• Nylon is more consistent, can have rounded tips and takes up less water.
• Natural bristle isn’t plastic and doesn’t shed plastic.
• Dental associations say soft, whatever the material.