All About Bad Breath: Teeth and Oral Health

A lot of us grew up thinking that bad breath was something that happened when people didn’t brush their teeth. When we were children, that probably was true for us. Tiny mouths just don’t have enough room to host enough bad breath bacteria to smell bad, unless they also have infected tonsils or adenoids, and brushing really is enough to stop bad breath for most kids. In teens and adults, however, teeth and oral health have a different role in determining the sweetness of your breath.

Dental Enamel and Fresh Breath

Dental enamel is the hard outer layer surrounding each tooth. Inside the tooth there is a kind of pulpy flesh containing blood vessels and nerves that the mineralized outer enamel of the tooth protects. As long as the enamel is intact, bad breath bacteria live on the tooth, not in the tooth. It just takes a quick brushing to get rid of those bacteria and freshen the breath.

When you are an older teen or an adult, brushing your teeth, even if their enamel is intact, may not be enough to stop bad breath. Only about 30% of the bad breath bacteria in the mouth live on your the brushable surfaces of your teeth. About another 30% live in the gap you can’t reach with your toothbrush between your teeth and your gums, and about another 40% of bad breath bacteria live in a film on the surface of your tongue.

There is a point at which brushing your teeth just doesn’t get rid of enough bad breath bacteria to keep your breath fresh. You definitely need to see your dentist twice a year to get your teeth cleaned, to remove plaque on your teeth beneath your gums that can trap bad breath bacteria (and tooth decay bacteria) inside. It also helps to use an oral irrigation device—flossing won’t get rid of particles below the gum line.

For the stinkiest cases of bad breath, it’s also necessary to brush or scrape the tongue. The idea is not go get rid of tongue tissue. It’s to lift the gray or yellow film off your tongue so bacteria aren’t continuously transferred to your teeth. If you don’t take care of bad breath bacteria on your tongue and underneath your gums, no amount of brushing will ever keep your breath fresh for more than few hours.

Even if you do all of these things, however, your teeth can still be a source of bad breath.

Crowns and Bad Breath

One commonly overlooked source of bad breath is the crowns used to replace broken teeth. A crown is a dental restoration that completely surrounds a tooth. You might need a crown when a cavity becomes too large to be drilled. Or you might need a crown when a tooth is knocked out at the gum line or higher, or, more commonly among people who are over 50 years of age, a tooth simply breaks out for no discernible reason at all.

The dentist may simply glue a crown to the remaining tooth, or it may be necessary to place the crown on a post and core to bind it to the bone that is left in the mouth. The problems with crowns usually occur when the root of the tooth has to be drilled out at the endodontist’s office and there is not enough bone left to secure the replacement, or when the tooth “snaps off” and the crown is only about 1 to 1.5 mm high. That’s only a fraction of the height of a tooth.

In these cases, crowns can come lose. Before they do, they usually crack open just wide enough for food particles to get caught underneath the crown. These food particles won’t decay porcelain or gold crowns, but they will release extremely bad breath odor. If you have crowns on your teeth, extremely bad breath odor that seems to happen for “no reason at all” may be a sign you need to see your dentist right away. Often crowns can be saved and reimplanted into the tooth, saving hundreds or thousands of dollars.

Fillings and Bad Breath

Another source of breath is loose or sharp fillings. Until about 1980, cavities used to be filled with gold, titanium, palladium, or a much cheaper alternative known as silver-mercury amalgam. Nowadays, the dentist is much more likely to use a bisphenol A-glycidyl methacrylate (BISMA) resin like urethane dimethacrylate (UDMA). The dentist drills a burr into the tooth and puts in a tiny amount of the plastic resin.

The dentist then tells you not to eat or drink anything for 2 to 4 hours. If you don’t follow the dentist’s instructions and let the resin harden into your tooth, the filling may come out, or it may simply come loose, anytime from a few days to a few decades later.

Loose fillings don’t generate as much bad breath odor as loose crowns, but they are a significant source of bad breath. Loose metal fillings may cut your gums or tongues, injuring soft tissues that will decay and cause odor in  your mouth. If you have fillings and you can’t track down any other source of bad breath odor, see your dentist. It will be much less expensive to replace a filling than it will be to replace a tooth.

Gingivitis and Bad Breath

Another time bad breath is a sign it’s time to see your dentist is when breath odor is caused by gums infected with gingivitis.

The pain and inflammation of gingivitis isn’t caused by the bacteria that accumulate as a film-like plaque on your teeth beneath the gum line. Gingivitis is actually your immune system’s reaction to the plaque, and attempt to get rid of it by dissolving your gums. As your own immune system breaks down the collagen in your gums, it decays and releases the volatile sulfur gases that cause bad breath.

It’s a lot better to let your dentist remove the plaque from your teeth than to rely on your immune system. If you notice bleeding when your brush your teeth or when you eat apples or bread, see your dentist right away. The dentist will not only help you get rid of the bad breath that gingivitis can cause but may also save your teeth.