The stiffness of toothbrush bristles are basically categorized by soft, medium and hard although there are additional types such as extra soft. Unless a dentist recommends another bristle type, most people are best using soft or extra soft toothbrushes. Hard, as well as some medium, toothbrush bristles can be tough on the gums by causing them to wear away. It may lead to having to have extensive, and expensive, dental work to repair the damage to gums. Bristles on toothbrushes vary in their length — many are all one height while others feature staggered bristle lengths designed to fit into uneven tooth surfaces.
A battery-operated toothbrush often has short bristles. Toothbrush bristles on all types of styles are usually in straight, even rows, but with triangular-shaped brush heads, the pattern will differ. Some triangular toothbrushes can adjust in different angles like dental instruments to better reach the back of the mouth and in between teeth.
Both synthetic and natural toothbrush bristle types are available today although synthetics are much more common. Nylon and polyester are the main synthetic materials used for toothbrush bristles. Some designer toothbrush brands feature coarse boar's hair bristles. Before synthetics became the norm for toothbrush bristles, boar's and horse hair bristle types only were used. Natural bristles may not be as resistant to bacteria as the synthetic kind; also, they're more likely to fall off the brush.
While many toothbrush bristles are white or off-white, they can be any color. Some types of toothbrushes that combine different bristle heights signify each level with another color. No matter what kind of bristles a toothbrush has, all bristle types tend to flatten within a few months. Toothbrushes used daily should be changed at least every three months according to many dental experts.
The longer toothbrushes are used, the more the bristles keep flattening and spreading apart rather than standing straight to best cleanse the teeth. Just like a household scrub brush used to clean tough stains, flat or crushed toothbrush bristles don't work as well as upright ones. Without changing toothbrushes every three months or sooner, users run the risk of not being able to scrub their teeth properly as well as effectively remove the sticky film called plaque that can build up on tooth surfaces to cause decay. When choosing a travel case to hold a toothbrush, care should be taken to find one that doesn't crush the bristles. Inexpensive, folding travel toothbrushes may be lower in quality; it may be better to buy a good brush with soft bristles.